After replacing valve stem seals and rings smokes. Signs of wear on the valve stem seals of a gasoline engine

They are also called valve seals. Why do we need these very small parts? Their purpose is to prevent the flow of oil from the head of the block into the working cylinders through the valve stem. By design, the products are a steel sleeve, “wrapped” with rubber with a twisted spring. Today, acrylate rubber is used for the manufacture of valve seals - a durable and reliable artificial material.

Timely replacement of valve stem seals prevents increased consumption oils and drop performance characteristics engine caused by the mixing of the air-fuel mixture and the lubricant composition.

Why are valve stem seals needed and how do they work?

The valve reciprocates due to direct contact with camshaft Timing. As it spins, an oil mist is created. In this case, the valve periodically enters the zone of the combustion chamber, where the presence of a lubricant is unacceptable. The valve stem seals just remove the oil from the valve stem, not letting it inside the cylinder block.

Over time, they age: rubber loses its elasticity, parts become stiff and lubricant begins to seep into the combustion chamber. In order to avoid excessive wear of the oil seals, they must be replaced in time.

Signs of worn valve seals

If it is possible to recognize the failure of these parts in time, then more serious engine breakdowns (parts of the cylinder-piston group) will be avoided. Main symptoms:

Thick smoke with a white or bluish tint is visible from the muffler pipe: it appears for a short time when the engine is started.
The concentration of smoke increases when you sharply press the accelerator pedal or change gears.
Lubricant consumption increases markedly (more than 1 liter per 1000 km).
Oiling is found on the spark plugs, they have black soot. This is due to the fact that when high pressure is created in the combustion chamber, oil particles are literally squeezed out through micro-gaps (enough 0.3 mm) in the candle thread and traces of lubricant consumables are visible even around the screwed candle.

Wear of valve stem seals cannot be avoided: these components of the gas distribution mechanism operate under increased load. In just one minute, the valve manages to make 150-1200 “walkers” (cycles). Plus, the products are affected by an aggressive environment: and exhaust gases.

The question arises, when to change the valve stem seals? If you bought a new car, then you need to do this after about 50-70 thousand kilometers (on imported cars mileage can be 180 or more thousand km).

If you ignore the above signs of oil seal wear, you should expect problems with the engine, namely:

power reduction (the car will become worse “pull”) due to poor performance of oily candles;
"swimming" revolutions on Idling;
When the rpm drops, the engine may stall.

It is also worth paying attention to dynamic characteristics car - for example, acceleration, and fuel consumption. If these two parameters have not changed, then we can talk with a high degree of confidence about the wear of the valve seals. This is also indicated by the normal compression in the engine cylinders.

Replacement of valve stem seals

The duration and complexity of this process depends on the brand of car and the specific model. But the general principles of substitution can be stated. To successfully replace valve stem seals without removing the head, you must:

Cool the engine completely and remove the valve cover.
Match the marks on the pulley, distribution and crankshafts.
Loosen the drive and remove the camshaft.
"Dry out" the valve springs (it is better to use a puller).
Using pliers or a special collet, remove the valve seals.
Take new products, lubricate their inner surface with engine oil. The same needs to be done with their seat.
Slide the valve seals onto the stem and press them in with gentle blows with a rubber mallet.
Put back the springs and dry them.

If there are suspicions that the valve stem seals have not been changed for a long time, you will have to remove the cylinder head and clean the elements of the cylinder-piston group from carbon deposits.

Replacing caps on VAZ 2121 (16 valves)

It is best to carry out this operation on the removed cylinder head. But if this cannot be done, do-it-yourself valve seal replacement can be done on the spot. You need to prepare in advance:

When everything is ready, you can go directly to the process. The algorithm of actions is as follows:

Disconnect the positive terminal from battery, remove high voltage wires and remove the spark plugs.
Set the top dead center, as you do when changing the timing belt (the marks on the camshaft, pulley, crankshaft must match).
Take a 12mm socket wrench and remove the valve cover.
Pull out the plugs connected to the sockets.
Remove the ignition coil.
Remove the throttle (if it is dirty, then take the opportunity to clean it).
Dismantle the valve cover and unscrew the screws that secure the rocker arms (pull them out too).
Take the squeezer and “dry out” the valves, after wrapping the device with a rag so that the valve retainers do not scatter in different directions. One part of this device is fixed, and the other presses on the valve disc, while compressing the spring and releasing the "crackers".
If the valve, when exposed to a tool, goes into the combustion chamber, then you will have to insert into the candle hole wooden block, or similar device to stop the valve.
Remove the worn valve stem seals from the bushings and press on new ones. Reassemble in reverse order.

It is worth taking seriously the choice of valve stem seals for the VAZ2112. Experts recommend the following kits:

2112-1007026: these are original products manufactured by AvtoVAZ and installed on the conveyor - ideal for a Russian car;
setMaster-sport;
Herzog;
trialli;
STD "Reserve";
Goetze: this manufacturer is worth dwelling on. Most professionals prefer these products, despite the higher cost. The fact is that valve seals from this company are easier to install (the risks of damage are minimized) and they last longer than even “native” VAZ ones.

When buying oil seals for a foreign car, you need to consider the design of the caps. For example, on Japanese products, there is a protrusion on the inside that matches the corresponding groove on the sleeve.

It is clear that such valve seals cannot be installed on European, American or Russian cars. It is worth noting that removing and installing valve stem seals with your own hands will cost less, even taking into account the purchase of a “raskuharivatel”, than a trip to a car service. If there is no opportunity to immediately replace the valve stem seals, then you can try to delay the inevitable repair using special additives. They are able to seal the gaps between the valve and its stuffing box for some time. Autochemistry of this kind will cost less than replacing caps (even independently): it allows you to continue to operate the car for some time. The most commonly used additives include:

Wagner (USA);
Liqui Moly (Germany);
Lavr (Russia).

Why You Shouldn't Drive With Worn Valve Seals

When lubricant enters the combustion chamber, fuel and lubricants are mixed, as a result of which the oil begins to turn into a combustion product and settle on the electrodes of the candles in the form of black soot. As a result, sparking becomes unstable, the motor is unstable and does not develop full power. Contamination of candles will sooner or later lead to the failure of one of the cylinders. Another threatening nuisance is the burnout of one or more valves. This is also fraught with cylinder failure and a sharp increase in oil consumption.

Many car enthusiasts and owners of used cars are faced with such a problem as smoke when starting the power unit, or when gaining high speed, and they will not understand anything from where it comes from. At the same time, in some cases, the motor smokes white smoke, or smokes black smoke. Of course, this is evidence that there are some problems with caps or piston rings. Below we will talk about what to do when the engine smokes, how to understand rings or caps are the cause of smoke in the engine.

Cause of smoke in the exhaust pipe

In order to understand the question of why the engine smokes, you need to have an idea of \u200b\u200bwhat happens in it during operation.

A fuel mixture is formed in the combustion chamber, which is compressed by a piston and ignited by a spark from a spark plug. The mixture is supplied through the intake valves, and the spent mixture is discharged through the exhaust valves. The pistons have special oil pick-up rings, they are needed in order to collect excess oil on the walls of the cylinders so that they do not enter the combustion chamber.

Engine valves also have special seals (caps), which serve to ensure that the oil in the cylinder head does not enter the combustion chamber. In addition, candles also play an important role, and if they have a weak spark, or the gaps between the electrodes are incorrectly set, then the fuel mixture in the engine will not burn out completely.

Based on this, it is possible to identify such causes of engine smoke.

Spark plug . If the spark plugs are faulty, that is, they give out a weak spark, or the gaps between their electrodes are set incorrectly, then the fuel mixture does not burn completely, and is removed from the combustion chamber with blue smoke. In the most severe cases, it may be black.
Piston oil pick-up rings. As mentioned above, oil pick-up rings perform the function of cleaning the cylinder walls of excess oil so that it does not enter the combustion chamber. They are subjected to a powerful force of friction. If they wear out, the oil enters the combustion chamber and ignites along with the fuel mixture. In this case, black smoke appears. Similar functions are also performed by engine rings, which also take excess oil from the surface of the cylinders and can wear out over time.
valve caps. These are seals that serve to ensure that the oil in the cylinder head cannot enter the combustion chamber, and are made of dense rubber. When it wears out, the lubricant enters the combustion chamber and ignites. This produces white smoke (or bluish).

The last two causes of smoke will be discussed below. If a motorist notices the appearance of blue or blue smoke, he needs to pay close attention to the operation of the spark plugs of the power unit and diagnose them, or change them.

It must be remembered that sometimes the cause of smoke in the exhaust pipe can be bad gasoline. It may contain various additives or additives that will create smoke of black or another color. This problem usually disappears when refueling with other fuel.

Diagnostics of malfunction of oil rings of the engine

As mentioned above, if the engine smokes black, then the whole problem is that the piston oil rings are worn out, and lubricants enter the combustion chamber.

Ignoring this problem can lead to the fact that the rings will not remove the lubricant, and therefore, it will constantly need to be topped up. In addition, rings may lie down, and they will need to be decarbonized. How to decoke rings that are stuck can be found in other publications. But it is better to do this at a specialized service station.

Now let's move on to the question of how to diagnose this problem.

There are two ways, the first is a compression check, which will be discussed in detail below.

The second is diagnostics while running power unit.

In order to determine the problem with the rings, it is imperative to warm up the engine to operating temperature, since this problem only appears when the power unit is running hot.

Then press the gas pedal, giving standard or increased speed. If with exhaust pipe black smoke will go, then the problem is in the rings, and they need to be changed.

How to replace piston rings in this case. Here you have to disassemble the cylinder head, remove the pistons, buy a new set of rings and replace them. If the car is foreign-made, then it is better to entrust such work to specialists, since it will be problematic to do this without removing the engine.

It is important to remember that if the problem is in the rings, then the engine will generally not start well after a long downtime.

Diagnosis of malfunction of valve caps

If the engine smokes white, then the problem is in the caps. At white smoke may also have a bluish tint. Based on this, the motorist needs to urgently change the seals on the valves, otherwise he will face a large engine oil consumption.

Such a problem can be identified on the cold operation of the motor, or in the process of movement.

Let's consider the first case. The motorist must put the car in a garage or other place, and wait until the engine cools down. After that, put in neutral gear, and start the engine, giving speed.

When winding up in this way, white or gray smoke will pour out of the exhaust pipe. This means that oil enters the combustion chamber through the valve caps.

In the second method, the driver is required to be observant. When the car is moving, it is necessary to disperse it, then brake the engine, and again press the gas pedal, giving significant speed. In this case, you need to constantly look in the rear-view mirror. If white or gray smoke pours out, then you can safely diagnose the malfunction of the caps.

What to do in this case. This problem can be solved in your garage. You just need to remove the old seals and replace them with new ones. Such work does not require great skills and even a beginner can handle it.

It is important to remember that if the machine still smokes with the replaced oil seals, then the problem may be in other engine components, so in this case it is better to contact specialists and conduct professional diagnostics.

Diagnostics using compression

You can identify the above problems with the power unit with special diagnostics using a compression gauge. This is a device that measures pressure. You can do such a diagnosis in your garage.

To do this, you need the help of a friend and the presence of the device itself.

To do it correctly, you need to adhere to the following algorithm. First you need to put the car in the garage, and warm up its engine to operating temperature.

After that, disconnect the candle of the first cylinder, and insert the compression gauge there. Using the starter, start the engine for a few seconds (crank the crankshaft), and remember the pressure that the device shows. Next, you need to pour no more than 20 grams of oil into the cylinder chamber, and turn the crankshaft again. If the pressure in the first case is low, and in the second case it rises, then the problem is in the piston rings and they need to be definitely changed.

As you can see, there is nothing complicated in such a diagnosis, but it helps to identify one of the problems with the appearance of smoke.

It is important to remember that the loss of engine power during high speed or load also indicates that the piston rings are worn.

The reason for the appearance of smoke of different colors from the exhaust pipe may indicate several problems in the power unit. If they are diagnosed on time, then large deviations in the operation of the motor will not appear. If you start, then serious damage can occur, and high costs for their correction.

Good day to all
I have a 99 premaska. I got it in February - this is my first car :) So far I have invested a lot of money in it, starting from all consumables / seals and suspension parts, ending with soundproofing and replacing all the acoustics in a circle. Literally all this time, the machine was regularly in the services, because. did for himself and literally worked for her. At the very last moment, I left an oil change, because. the owner, who reported that the oil does not eat up, and the planned (every 10 tons) replacement will be in 3 thousand. Having left during this time (I didn’t travel much, occasionally on business) a little less than a thousand kilometers, I drove the gearshift knobs to adjust the loose backstage, and at the same time, earlier than indicated to me for replacement by 2 thousand. oil, because I was impatient to change it, I even bought 8 liters from a dealer so that there are no fakes, and rinse before, baying the second "set" next for the summer. Changed with a complete drain of the old at my request. Judging by the remainder in the canister, they filled in 3.5 with a filter replacement, which is the norm.
When I picked up the car, handing it back in the box, I noticed that I had smoked the entire repair box with white exhaust smoke. Standing nearby, went out to watch the exhaust. It smoked a little, then it seemed to disappear altogether. Calmed down, he took her to the painter for minor finishing touches (scratches, Kotska).
I was only able to pick it up after 3 days. Driving back from the stand, I noticed the smoke, again this smoke! Starting to finally understand that something is wrong here, I again observe the exhaust. It's warm outside, about +20 in the sun, noticeably warmer than on the day I picked it up from the service. The smoke, meanwhile, began to subside again as the engine warmed up. I ran my finger - there is condensate on the end of the pipe. Everything seems to be in order. The smoke is barely visible.
I decided to drive home around the city, bypass. During the route, periodically turned off the music, listened to the movement. Turnovers - as usual. The liquid temperature is in the middle of the scale. The oil pressure indicator and other things related to the engine on the tidy do not light up. Sounds are all right. Everything seems to be ok.
came and installed. Today I began to google, ask questions to motorists with experience. There were suggestions about the breakdown of the cylinder head gasket, etching of the coolant into the cylinder. The serviceman from whom I service the car (at the time of picking up the car, he was absent from the box), suggested by phone that these could be stubborn valve seals. The only question is that this smoke did not exist before.
And finally, almost the denouement - in the evening, having accumulated the theoretical course of a young fighter, I come to my Masa, check the coolant level, which is 2 centimeters in the tank, and under the radiator cap - under the neck, which seems to be excellent, I make sure that there are no whitish streaks on the oil filler cap neck of the engine and camshafts, I start the heart of the masyanya. Factory in a fraction of a second, then seven seconds of quiet, flawless work that seemed like an eternity. And suddenly! - as if fresh grass was thrown into the fire - thick white smoke begins to pour and slowly rise into the air. Dense smoke, obviously not condensate, and what the hell is condensate when it’s already over 20 degrees outside and in such conditions the exhaust activity should already be indistinguishable. Half a minute passed (no less), the density of the smoke decreased several times, becoming an exhaust visible to the eye. The father, who volunteered to help, at my request, adds gas at idle, and the smoke screen spreads across the yard with renewed vigor, hiding everything from view. During gassing, I tried to see the bubbles in expansion tank, which would indicate exhaust etching into the cooling system. NOTHING! The liquid, perhaps not having time to warm up, did not even move anywhere during the entire 5 minutes of engine operation, no bubble, no twitching, no oil stains on the surface of the liquid. Nothing: (Turning off the engine and opening the radiator cap, I also didn’t see any oil there. Under the oil filler neck, everything is also in normal mode, there is no emulsion on the dipstick, the oil level is closer to the maximum. Only the yard of 100x50 meters is half hidden in smoke. And it has a little smell gives off gasoline, not very reminiscent of oil, and the color is not gray or black, but white.And I did not wait for traces on a white sheet of paper attached to the exhaust.
In general, I'm completely confused.
And finally, introductory (sorry for the end of the topic):
dvig- fp-de 1.8 petrol injector, mileage 178t
oil before change 5w-40 castrol synthetic http://castrol.com.ru/castrol/magnatec_sae40c.php
oil after change 10w-40 liquid moly semi-synthetics http://catalogue.liquimoly.ru/index....talogue_id=424
(the seller claimed that he did not reel, he did not need it). By indirect signs, I believed him then, now I don’t know.
Antifreeze - blue. Just blue :) the only thing that did not have time to change.
I chose the oil by studying the forums, since the engine was already running, semi-synthetics should be shown to it for use. Passed despite the seller's statement that he does not eat oil. So calmer. The figure of low-temperature density - in connection with the upcoming summer in Krasnodar (temperatures from 30 to 43 in the shade), I think that's what we need. I took Liquimoli through a friend, from a supplier, so that there are no fakes.
I confess, I did not measure the coolant level after the purchase, how could I know. Maybe the antifreeze was leaving - but as I wrote above, I did not see this by indirect signs. Unscrew option drain plug crankcase and look for the presence of a heavy water fraction at the bottom of the oil? or again unscrew the recently replaced candles and try to find “cleaner” ones, which, in theory, could “eat up” the coolant. Would you have time? moreover, replacing the old candles, I noticed that almost everything is fine with them. "Almost" - because the end is slightly coked, but the terminals of the arresters are clean and reddish, I threaded the edges - well, the mixture was over-enriched, I changed it because of this fuel filters(both) in the tank, and the air filter. I wanted to clean the nozzles with ultrasound myself or in the service during the week. So all these metamorphoses with the engine began to occur after an oil change in the service. Did the cunning owner use an anti-smoke additive in the old oil? But damn it, the smoke is now pouring out so much that it can only be appeased by a young tree if you drive it into the exhaust.
Help, good people. It’s a pity for the machine, it’s scary to say how much I invested in it: (Ask questions, maybe I didn’t take something into account in my story. I’ll try to answer. Maybe one of my friends came across. I really look forward to advice. Of course, I’ll describe myself if I can (and have enough money) to solve this problem.

Quite often you have to notice that increased smoke appears from the exhaust pipe of a car. Sometimes situations reach the point that the car is literally shrouded in clouds of thick smoke. It is quite obvious that for every motorist the appearance of excessive smoke indicates the appearance of certain problems with.

We note right away that not always, but often increased smoke indicates serious. At the same time, it will not be difficult for experienced drivers to determine the cause by the color and composition of the exhaust. However, for beginners, it is not always easy to understand why the engine smokes, as well as to establish the cause and identify rings or caps. Let's figure it out.

Read in this article

White or black smoke from the exhaust pipe

Let's start with the main types of smoke for a better understanding of the problem. So, white smoke from the exhaust pipe is quite normal for cold engine warm-up modes. Moreover, it is a mistake to believe that it is smoke. It's actually steam. Vaporized water is a natural product of the motor.

In unheated exhaust system this vapor partially condenses and becomes visible, and water usually appears at the end of the exhaust pipe. As the engine warms up, condensation decreases.

The colder the environment, the denser the steam. At temperatures below 10 ° C, steam is also formed on a well-heated engine, and in frost at minus 20 - 25 degrees it acquires a thick white color with a bluish tint. Humidity also affects the color and saturation of steam. The larger it is, the thicker the steam.

Note that if steam is visible in the warm season, it is quite possible that this is due to. Its shade depends on the composition of the coolant, weather, light, and also on the amount of coolant in the combustion chamber. Sometimes it can take on a bluish tint, resembling "oily" smoke. But, unlike oil smoke, which leaves a bluish haze in the air for a long time, the vapor quickly dissipates.

It is quite difficult for an inexperienced motorist to appearance determine what is the source of the smoke. In this case, you can use a proven verification method. To do this, on a well-heated engine, briefly close the cut of the exhaust pipe with a sheet of white paper, while the condensed vapor in the form of water droplets will gradually evaporate when it hits the paper and will not leave obvious greasy marks.

If this simple test confirmed that exhaust system it is steam that comes out, not oil smoke, it is necessary to take measures to eliminate the malfunction that contributes to the penetration of coolant into the cylinders.

Most often, liquid can enter the cylinders through insufficient traction (in winter, coolant leakage is often observed at the junction of the block and head), burnout, and less often as a result of formation. By opening the radiator cap or, it is easy to detect the smell of exhaust gases and an oil film on the surface of the coolant.

All problems associated with white smoke from the exhaust pipe require the elimination of not only direct causes, but also a mandatory check of systems that can affect their appearance: the switch on sensor, the clutch or the fan itself, the condition of the radiator, its plugs, hoses or connections. If white smoke and its accompanying defects are noticed, then the car cannot be operated, as the defects progress rapidly.

We go further. Black smoke from the exhaust pipe indicates over-enrichment fuel-air mixture or deterioration of fuel combustion conditions. Therefore, we are talking about malfunctions. Such smoke is usually clearly visible against a light background and represents soot particles - products of incomplete combustion of fuel.

Black smoke is accompanied by high fuel consumption, often poor starting, unstable engine operation, high exhaust toxicity, and often loss of power due to a suboptimal air-fuel mixture.

It is important to understand that monitoring the symptoms and quickly identifying the problem will further reduce the cost of repairs and avoid serious and rapidly progressing engine breakdowns.

Smoke from the oil filler neck*

Which can sometimes be seen, for example, if the oil filler neck is opened on a running engine. On a good (i.e. serviceable) engine, air will simply come out from there (as an option - with an admixture of oil mist, which is not a malfunction). If the engine consumes a lot of oil and strong smoke comes out of the neck, then the piston group is worn out. If the engine consumes oil, and it is clean from the neck, then the matter may be (but not necessarily) in the valve stem seals.

* So this symptom is more likely not indicative of wear on the valve stem seals.

The threaded part of the candles is covered with oil

This is also one of the symptoms of the need to replace valve stem seals. However, not always. Those. it happens that the caps already require replacement, but the threaded part of the candles is still dry. For there is still not too much oil getting into the combustion chamber, it has time to burn out.

Why is the threaded part of the candle covered with oil under the conditions when it enters the combustion chamber? It would seem that if there are gaps in the thread between the spark plugs and the block head, then they are minimal and do not exceed 0.2 mm?

Consider the process of the engine. The fact is that at the moment of inlet of a portion of the combustible mixture, oil enters the cylinder, while there is a vacuum in the cylinder (as well as in the threaded gaps of the candles). The mixture is then compressed. Naturally, it (including the oil and gasoline contained in it) begins to penetrate into all places where it is possible, including the threaded gaps of the candles. The mixture is then ignited and burned. It burns almost everywhere, except, just, for threaded gaps. For they are very small (in the region of 0.1 ... 0.3 mm), as a rule, combustion cannot spread into such small gaps. As a result, oil accumulates in the threaded gaps. Gasoline evaporates, because the candles are heated.

Candles are covered with black soot. Increased smoke from the exhaust pipe

Nagar can (but not necessarily) be oily. As a rule, when the valve stem seals are worn, it is terry. Although, too rich a mixture can also give terry black soot. Blue-gray, sometimes black smoke from the muffler indicates wear of the cylinder-piston group, as well as an excessively rich mixture.

However, similar symptoms are also observed when the valve stem seals are worn out (blue exhaust during regassing), the ignition system malfunctions (the ignition timing is incorrect, the high-voltage wires, the distributor cover, the slider, etc. are “broken”, and also, possibly, a malfunction ... alarm), violation adjustments of the fuel supply system (for example, carburetor, injectors, etc.).

Those. black smoke from the muffler and black-coated candles are far from always evidence of an overly rich mixture. Both of these signs also appear both when the valve stem seals are worn out, and when the ignition system is disturbed. Why?

Because if the ignition system malfunctions, the spark on the candles will be defective, although in appearance it may be quite acceptable. Accordingly, the combustion of the oil-fuel-air mixture will also be defective. In particular, the oil and gasoline contained in the mixture will burn WORSE (than with a good spark), i.e. black soot will form, giving the appearance of an overly enriched mixture. For example, this is exactly what was observed in the case when it was “cunningly” broken.

Alarm malfunction

It can also be the cause of carbon deposits on spark plugs if circuits related to ignition pass through it. A common case is when some connectors in the alarm have bad contacts (when they are old and / or made of Chinese metal). In this case, the ignition will be either excellent, or “not very”, then (for a fraction of a second) it will be completely absent. And so - all the time.

There was a case when the car periodically stalled on the move after 10 ... 20 minutes of driving. And after - flatly refused to start. However, after a 10 ... 15 minute parking incident, it started up, as if nothing had happened and drove as long as necessary.

Note: exactly the same behavior of the machine in another case was the result of a malfunction of the valve stem seals.

In addition, the car often (but not always) stalled when trying to move uphill. The recommendations of the servicemen to repair the power system, of course, did not lead to anything at all. They only cost money and time to think. However, the problem was completely removed after the restoration of electrical contacts in two alarm connectors (by removing them and lightly crimping the connectors).

Why did the car start after 10 ... 15 minutes of parking? Because during this time the signaling unit cooled down a little, the contact parts of its connectors slightly changed in size (under the influence of thermal constriction), slightly shifted relative to each other (i.e., the “male” connector was slightly displaced relative to the “mother” connector ”), there was a sort of scratching, slippage of their contacting surfaces relative to each other, and contact was restored again for some time.

Why does the engine sometimes stall when driving uphill? Because in the signaling unit, which is under dashboard, when the orientation of the machine relative to the vertical changed, the signaling unit moved slightly to a different position, as a result, electrical contacts were sometimes broken. And when the car moved to a horizontal surface, contacts were restored.

Smoky exhaust when regassing

Symptoms of the formation of smoky exhaust during regassing are similar - both in the case of a malfunction of the valve stem seals, and in the event of a malfunction of the cylinder-piston group. The difference is that if the caps are faulty, then repeated regassing (4 ... 7 times) usually leads to the (temporary) disappearance of smoky exhaust. Those. There is usually no permanent smoke. Whereas in the event of a malfunction of the cylinders and pistons, the smoky exhaust DOES NOT DISAPPEAR after several regassings.

The reason is that in the first case, the oil accumulated near the junction of the edge of the valve stem seal and the valve stem, as a result of a sharp pressure on the gas pedal, is TEMPORARILY sucked out through the gap between the valve stem and the guide sleeve, into the cylinder, which leads to several smoky exhausts at regassing. When all the nearby oil has been sucked out, there will be no smoky exhaust (until the oil accumulates again). Whereas in the latter case, oil enters the cylinder, regardless of whether the gas pedal was sharply pressed or not; no matter how many times and with what frequency it was pressed.

When idling, when the cylinders and / or pistons are worn, the smoke will be thick and bluish (like old Soviet motorcycles, Druzhba-type chainsaws), while when the valve stem seals are worn, it will (at first) seem to be “bluish”. If you look at the exhaust pipe from above with the engine running, it is not always visible. But looking ALONG the exhaust pipe, when viewed from behind the car, sometimes (but not always) makes it possible to see such a bluish haze.

Also, if, when the engine is HOT, white smoke comes out of the muffler, then this is also a sign of wear of the valve stem seals, but not of the cylinder-piston group. By the way, another reason for the appearance of white smoke on a warm engine is the ingress of coolant into the engine cylinders due to a malfunction of the head gasket.

Note that the appearance of white smoke disappearing after warming up on a COLD engine, on the contrary, is a completely normal symptom. After all, as a result of the combustion of the fuel-air mixture, in particular, water is formed. The vapors of which become visible until the engine and muffler warm up. For the same reason, water drops can even fly out of the muffler. It often happens that water drips a little from the end of the muffler pipe.

When the muffler warms up, the water vapor on its walls will no longer condense - and the white vapor will disappear. The water will stop dripping.

Too rich combustible mixture will also give an exhaust of increased smoke, including during regassing. Which, it seems, SHOULD NOT disappear after repeated regassing.

However, in fact, not everything is so simple. There was a case when, due to a too rich fuel mixture, the car engine started with great difficulty "hot" (whereas "cold" started with half a turn). After repeated re-gassing, the exhaust of increased smoke (blackish) DISAPPEARED. However, the problem was - it was in an overly enriched fuel-air mixture.

Increased fuel consumption

The fact is that the oil that enters the cylinders during engine operation makes it difficult for the combustion of the fuel-air mixture. Accordingly, in order to remove the required power from the engine, a larger amount of mixture will be needed than in the absence of oil in the mixture.

By the way, not only valve stem seals, but also almost all other engine malfunctions also lead to increased fuel consumption, whether it be wear of the cylinder-piston group, a malfunction of the ignition or alarm system, or a non-optimal composition of the combustible mixture.

Loss of power and throttle response, failures in engine operation

This manifests itself in reduced dynamics when accelerating, overtaking. And also there may be "failures" when you press the gas pedal. Those. you press the gas, and the car SOMETIMES, instead of jerking forward, it seems to slow down, the engine stalls. If you release the gas pedal or press it SLOWLY, the engine runs normally. In such cases, it is usually recommended to adjust or repair the fuel supply system. More advanced ones also recommend paying attention to the ignition system.

This is often true, but not always. Sometimes - with a sharp increase in vacuum during the intake stroke of the fuel-air mixture (which is the result of a sharp pressure on the gas pedal), this vacuum is transmitted through the valve guides to the valve stem seals. If they are worn out, then a portion of oil is sucked in, which enters the cylinder, filling the spark plug, i.e. (at first - temporarily, and then - permanently) turning it off from work. This explains the "failure" in the engine. If the vehicle is equipped catalytic converter, he "for some reason" will soon fail.

Oil gets dirty quickly

Yes, this is also one of the symptoms of valve stem seal wear, which is far from known to everyone. Why does the oil become contaminated, becoming dark, then black? There are usually two main reasons for this:

wear of engine parts and the ingress of wear products into the oil
soot formation caused by the combustion of oil contained in the fuel-air mixture and its subsequent flushing

Well, quite banal reasons, for example, disruption of work (or absence) air filter, as a result of which dust from the air enters the cylinders, which causes oil pollution or simply low-quality oil that quickly collapses during engine operation, we will not consider here.

The first is generally known. But, at the same time, there should be metal particles on the magnetic oil drain plug. And if there are few or none at all?

Then, obviously, the black particles that cause the oil to darken are nothing more than coke washed off the cylinder walls. Indeed, in most modern engine oils contains quite effective detergent additives, which help to wash off carbon deposits. If not for them, then as a result, the piston rings would simply coke. Fast. Well, their presence in the oil saves, thereby, the engine. True, the whole blow is taken by the oil, which quickly becomes contaminated.

Since soot is formed GRADUALLY, its particles are very small in size, they, being washed off from the walls of the cylinder, freely pass through oil filter and for this reason remain in the oil, causing the need for its accelerated replacement.

However, too rich a mixture can also take place here. Which also gives black soot on spark plugs, as well as on the surface of the cylinder. Accordingly, after this soot is washed off with oil, it will enter the engine crankcase.

glow ignition

It is expressed, in particular, in the fact that the engine continues to run for several seconds, or even more, even after the key has been removed from the ignition. Yes, and this can also be a symptom of oil getting into the combustion chamber, including as a result of a malfunction of the valve stem seals. Why?

Because modern gasoline cars, perhaps, without exception (both carburetor and injection) are equipped with a fuel cut-off system when the ignition is turned off. For example, if we talk about carbureted car, then in carburetors, as a rule, there is an idle solenoid valve that shuts off the flow of the working mixture when the ignition is turned off.

By the way, for reference, modern petrol car does not have to be injection. For example, many military vehicles are, as before, carbureted. The reason is probably clear to you: military vehicles are required, among other things, increased reliability and high maintainability even in the "open field". It is clear that a knowledgeable person will be able to clean and adjust the carburetor quickly and in almost any conditions, while for adjustment injection engines can't do without a computer. Well, cleaning nozzles in the "field" is definitely impossible without special equipment. And, in fact, the military will not carry a diagnostic computer and other devices with them just to use the injector, when it is quite possible to get by with a carburetor that has proven its reliability and quick maintainability. Well, which slightly increases fuel consumption, slightly increases the toxicity of exhaust gases. And, nothing more.

Then, the more electronic parts in the car, the higher the probability of their failure, for example, when exposed to an electromagnetic pulse.

So, if even when the gasoline supply is turned off at idle, the engine continues to work, therefore, there is something in its cylinders that can burn out. In this case, it is nothing but oil. Located there in SUCH concentration at which the engine is still able (but not always) to work. It is clear that when the caps are even more worn out, even more oil will enter the combustion chamber, then the glow ignition may disappear. But, at the same time, the car will be difficult to start, there will be increased oil consumption, etc.

The car is difficult to start "hot"

If it is difficult to start “cold”, then the reason is often not at all in the valve stem seals. There, most likely, more obvious reasons, such as wear of the cylinder-piston group, fuel supply failure, ignition malfunction, including, as already mentioned, alarms. And also - a malfunction of the battery, starter.

But if “on a cold” engine it starts with half a turn, but on a hot one, paradoxically, you have to spin it with a starter for 5 ... 10 seconds or even more (or even the car’s engine stalls as soon as it warms up well), then the reason for this may well be be worn valve stem seals.

The fact is that in a cold engine, the oil is also, of course, cold. And having a high viscosity, and therefore - reluctantly leaking into the gap between the valve stem and the working edge of the valve stem seal. When the oil warms up, its viscosity decreases (sometimes by several orders of magnitude), and it is much easier for it to pass into this gap.

However, a violation of the composition of the combustible mixture, ignition malfunctions, alarms are also not excluded, of course.

Exhaust gas has a very disgusting, suffocating smell.

It is clear that the smell of exhaust gas cannot be called natural, pleasant and safe.

However, having sniffed, say, cars driving in the United Arab Emirates (UAE), I concluded that the situation with exhaust gases is MUCH (!) Better there than in Russia. It seems that a continuous stream of cars is driving, and the exhaust smell is insignificant ... Sometimes, even leaning close to the exhaust pipe, somehow you don’t catch that nasty smell that comes from Russian cars. One of the reasons for this is, of course, quality gasoline. Which, by the way, was also much cheaper than in Russia, at least until the ruble was sharply lowered against the dollar and many other currencies.

Yes, after all, after all, exhaust gas, what to expect from it. However, when the combustible mixture is of poor quality, incorrect (in particular, as a result of a large amount of oil in it), then, naturally, the smell of the exhaust becomes much, much more disgusting. In such cases - it is worth standing a little near the exhaust pipe when the engine is idling - and you want to get away from this smell somewhere. The neutralizer, we repeat, at the same time fails very quickly.

Therefore, if the exhaust of a car has become somehow especially unpleasant, suffocating, not the same as it was before, you should pay close attention to engine parts through which excess oil can enter the combustion chamber. In particular, these are valve stem seals.

However, a very rich combustible mixture can also be the cause of such a smell.

Worn valve guides, valve stems

Of course, the wear of their working surfaces in itself does not indicate the wear of the valve stem seals. He simply speeds it up, and significantly. It also makes it useless to replace the caps with new ones.

The fact is that if the holes in the guide bushings and / or valve stems are badly worn out, even a new high-quality valve stem seal will not be able to fully retain oil during engine operation. Which will enter the combustion chamber, as with worn caps.

So if, after replacing the valve stem seals, those symptoms of wear remain, then you should think about repairing (replacing) the valves and their guide bushings. And then about overhaul(replacement) of the engine, because, as a rule, by such a time, its other parts are also partly exhausted. It makes no sense to change only the bushings and valves, if after another 20 ... 30 thousand the chain, sprockets (pulleys), rockers, pistons, rings, as well as cylinder boring, grinding of the crankshaft journals are to be replaced.

How to measure play in valve guides? If roughly and roughly, then the backlash can be considered large if, when the valve stem is swaying from side to side, it feels much higher than it was on a new (refurbished) engine. If it is much higher than the typical felt backlash for a particular engine model. Well, for a more accurate measurement, of course, you need to remove the block head, get the valves, etc.

Also on topic

Jagged Crown Acquire the Jagged Crown of skyrim.

mods skyrim revival of the dark brotherhood 2

Cutting Room Floor - Mods and plugins for TES V: Skyrim Special Edition

Where can I find spell tomes in Skyrim?

Daedric Princes: Mehrunes Dagon