After the fan is on the engine starts to rev

When the fan starts to vibrate a little and the rpm rises.

In general, I noticed one peculiarity, when the fan starts a slight vibration and rpm rises. it feels like the engine is tripping. As soon as the fan stops spinning, everything runs smoothly. How is it related to the engine and what happened? it was not before. mileage 40 tons 1.5 years the car

PS fan is the one that cools the engine and not the cabin)

Why the car engine is Trojit, and how to fix it

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Car owners, who know how a car engine works, know what the phrase “the engine is at a standstill” means. It indicates a problem with one of the cylinders. The expression itself appeared during 4-cylinder units, when one unit stopped working. Let’s understand the causes of such a phenomenon and the ways to fix the failure.

How the problem of the engine thrashing manifests itself

If the power unit starts to thrash, it is accompanied by several characteristic symptoms:

If you encounter one of the signs listed above, there is likely a malfunction in the cylinder block and it needs to be fixed. It may be a general problem, but it still affects one of the cylinders.

How to proceed in such circumstances? What is the cause of the problem and how to restore normal operation of the system.

To begin with, you should consider that the engine often trots when cold, in neutral, or in a particular mode of operation. A cylinder stops working due to the following factors:

Therefore, the causes of malfunctions should be looked for either in the fuel supply, compression, or spark generation.

If the power unit is tripping, it’s important to find the root of the problem as quickly as possible and get it repaired. Ignoring the importance of the procedure, you can cause serious damage to the engine and “get” into an expensive repair.

Improperly operating cylinder often still receives a portion of the fuel, which washes the oil mixture in the crankcase, provoking increased wear, mechanical damage and even ignition of fuel vapors.

Diagnostic features

First of all, you should determine which cylinder has stopped working. There is a fairly simple but effective diagnostic method that is suitable for cars with gasoline units.

To do this, start the engine and at idle start disconnecting the high direction wires in sequence, which are responsible for supplying the discharge to the spark plug. If it is disconnected on a functioning cylinder, the engine is thrashing even more intensely. If the failed component has been disconnected, no changes will occur.

When carrying out diagnostics in artisanal conditions you need to remember about safety, because there is a risk of getting an electric shock.

If we are talking about problems with the injection unit VAZ with direct fuel supply, the diagnostic process becomes even easier. You don’t have to sort out the wiring and jeopardize your safety. All you need to do is disconnect the injector control one by one. You should also find the cylinder, when disconnecting which does not show any changes in the operation of the engine.

Diagnosis of diesel engines involves sequential disconnection of fuel-air mixture supply. You can unscrew the nuts from the fuel wire one by one to check. The task is the same. to find the cylinder, which does not affect the operation of the power plant when it is disconnected.

Why are the cylinders failing?

Cylinder failures occur due to the following causes:

If the spark plugs are not the right size for your particular powertrain model, this can lead to critical failures. When an engine fails, its performance is drastically reduced, and the proper operation of important organs and systems is threatened.

If you were able to figure out which cylinder caused the engine problem, you need to proceed to restore normal performance. It is also important to check the spark plug by unscrewing it and looking for traces of fuel. If the contact points are wet or if there is no spark, it is an indication that the fuel mixture is too rich or too lean.

Problems with the plugs

Try installing a fully serviceable and working spark plug in place of the old one and evaluate the quality of the cylinder. If it runs normally, it’s a problem with the spark plugs. If not, you have to look for other causes of problems.

engine, starts

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Faulty wiring or ignition distributor

Do not ignore the high-voltage harness while diagnosing the vehicle. It is important to check the contacts and insulation. Make sure the terminals are intact, with no signs of corrosion or cracks. If damaged, replace the wiring and re-diagnose the spark plugs.

There is a quick method of checking the high voltage cables. To do this, start the engine in a dark, windowless room or at night. If there is no additional light, during the diagnosis you will be able to detect signs of breakdown in the form of sparks. Similar problem causes lack of voltage for the spark.

If the wiring is perfectly serviceable, check the distributor cap. Failures occur in different cylinders due to breakdowns of this part. Cracks in the cap indicate that the contact in the switchgear assembly has been damaged and the engine has started tripping.

Air suction

If you are sure that the spark plug is fully functional, and there are no problems with the high-voltage wires, you need to check the quality of the fuel-air mixture. In some cases, air suction changes the proportions of gasoline, preventing it from igniting.

The problem with the injectors

Onboard computer Р1336-Р1340 errors can also occur because of faulty or clogged injectors.

The best way to check the resistance without removing the frame is to check the resistance on the injector pins. Repair and oil replacement in Peugeot 308 automatic gearbox after the oil has flowed out. You need a multimeter in resistance measuring mode. The rated resistance of the injector is 12.6-12.8 ohms.

You need to check it only at the moment of malfunction. If everything is normal with the resistance, it remains to flush the injectors. it is better to do it on a flushing stand with a special liquid.

Throttle with actuator mechanism

We have already mentioned above that ECU corrects revolutions after switching on air conditioner.

It does it with the help of the throttle assembly, changing the angle of the damper position. If the choke is dirty, including its bearing, the choke will not turn and the rpm will not increase, and thus the engine vibration will continue.

Diesel engine

If the cold engine on the “diesel” is tripping, then there are also plenty of options here:

  • firstly, the compression in the engine may be too low (or absent at all). Here everything is trivial. the cylinder simply does not reach the necessary temperature for ignition of the fuel;
  • secondly, the nozzle can fail, which will deliver a jet of fuel into the cylinder with no signs of atomization. Here the cause may be a breakdown of the atomizers themselves (in this case you can save only by replacing);
  • Third, a malfunction or improper operation of the fuel pump is also one of the likely causes of a diesel engine tripping;
  • Fourth, wrong assembly of the engine and wrong ignition setting;
  • Fifth, swapped fuel pipes;
  • Sixth, failure of spark plugs and so on.

After start-up, it works fine, it throws up as it warms up

It happens seldom in real life, and the search for the cause may take a long time. Most likely, it will be difficult to find the cause without a minimum set of tools. Electrics are rarely to blame in this case, the most probable cause is purely mechanical. First of all, it is worth checking the compression and valve gap adjustment. Most likely, the valve clearance is broken somewhere. However, it is worth to check the spark plugs, wires and coil. But then you will have to go to service for more serious diagnostics.

Of course, we did not consider many reasons for the engine thrashing. Low compression, gauge errors, phase mismatch, and other things I left out on purpose. All this is difficult to diagnose without equipment and experience. And such troubles occur much less often than punctured wires and half-dead gas pump. But the methods of elementary search of the TNT reason, described above, can help in many cases. Well, not to drive the situation to necessity to look for runaway spark, it is enough just to change spark plugs and wires in proper time, do maintenance and not to forget about trivial defects in engine’s work.

engine, starts

Even the insignificant ignition skips because of the “almost” serviceable spark plugs can lead to a wire breakdown, and even worse. the coil, which can cost quite a lot. Driving with three-way is no good, either. If only petrol consumption increases and the dynamics fall, but no. the consequences can be much more diverse and very unpleasant. For example, increased vibration of the motor kills both supports and weakly fixed wiring elements. And also the automatic transmission electronics can go crazy, which does not understand why the crankshaft rpm is constantly jumping up and down sharply.

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In general, there could be all sorts of consequences, although all this could be avoided by buying some spark plugs for 300. So, if you can not do something yourself, it is better to give your car to professionals at once. Sometimes it’s a lot cheaper.


Cracks in the cylinder head or block are one of the most common causes of hot runaway. Metal is known to expand with increasing temperature, accordingly small cracks may enlarge and let coolant, little into the combustion chamber. It will interfere with the normal combustion of the mixture in the cylinder and the engine will be in a rush when warming up. The same effect happens when there is a widening of the crack in the gasket under the head of the block, when it is burned out.

Particular attention should be paid to engines with manual valve adjustment. The clearances should be set according to the manual to this type of engine, you can not ignore it. If the valve is jammed, it will not close all the way, the tightness in the combustion chamber is lost and the cylinder does not work when heated. Incorrect clearance setting burns the valve and the seat, it sags in the cylinder head and the process becomes irreversible.

Cotton piston rings are also the cause of unbalanced engine operation when the engine is hot. Here plays the role all the same thermal changes of the metal, uneven wear, overheating of the engine. Run-out of camshaft journals leads to the unbalance of engine. Engine warms up and shakes, throttles periodically, typical knocking noises appear.

In the cold the engine is inoperative: causes, methods of elimination

Many vehicle owners are faced with a situation where the engine is tripping when cold, but as soon as it warms up it levels out and runs all day. Many people puzzle over in search of the reasons of the given malfunction, and as a result they change spare parts, go to diagnostics and make expensive repairs. Let’s understand the sequence of operations when searching for the causes of touching when starting up, especially when the car also stops.

The main problem in troubleshooting is that the engine may be tripping for short periods of time. This point must be caught and the cause must be found. It is especially actual, when the car is checked in an auto service center. The car should be left overnight for the diagnosticians to look at it when it’s cold. Otherwise, it will be difficult to find the reason when the engine is hot, when it works normally.

Engine mechanics

First of all it is necessary to measure the compression on a cold engine. It should not differ from the standard value for this type of engine. As a rule, for common atmospheric gasoline engines, 12-13 atm is normal. If the indicator differs by 1-2 atm it is necessary to think about the problem in the mechanics of the motor.

If the difference in compression is no more than 1-2 atm, you need to measure the thermal valve gaps, with a manual adjustment of the timing mechanism (timing).

If the design provides automatic adjustment due to hydro-compensators, pay attention to the knocking on the side of the valve mechanism. If the sound disappears with warming up, remove hydro-compensators, check their performance.

engine, starts

The initial check of the scrolls is made on the engine, with the removal of the valve cover. Without removing the camshaft, put the cams in the up position, so as not to press on the valve to put pressure on the expansion joint. It should not press. Otherwise replace or flush.

In the case of low compression, check with oil, if the figure increases, it’s all about the piston group. If there is a slight increase in compression repair the cylinder head. If oil gets on tight piston rings, it closes micron-sized gaps and the pressure increases.

One of the types of mechanical damage is a punctured cylinder-head gasket. Depending on where the gasket is punctured, it will leak coolant, get into the oil, leak oil, or get back into the heating oil. If it gets punctured between the cylinders, you will lose compression.

The most costly problem is a crack in the cylinder head and short block. Hard to diagnose, expensive to fix. Metal expands and contracts depending on temperature, which is why the engine may be tripping exactly when cold.

Mechanical problem is the most common cause of cold engine noise.

Injector condition when cold

The second and very important problem of modern engines is the quality of fuel that we get every day at the gas stations. The disadvantages are not even in the quality of gasoline itself, but in the presence of water and condensation. Moisture enters the filling reservoirs under the ground from ground water, rain and is formed by the condensate. It comes in huge quantities. Pump picks up gasoline and pumps it all into our tanks. What to do in this situation.

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It is necessary to constantly preventive maintenance of the fuel system: wash injectors every 30000 km and pour pure alcohol in the tank in an amount of 350-500 grams of 20-30 liters of gasoline.

On a cold engine, a dirty nozzle does not give a proper atomization and fuel volume into the combustion chamber. Accordingly, the fuel-air mixture breaks its proportions and does not ignite. Injector system fails, consequently, the engine starts to stall when starting. With warming up, water in the injector nozzle goes away and the engine runs smoothly.

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Air suction

A common type of malfunction in the cold. Rubber bands on injectors, intake manifold gaskets get compressed in cold weather and let in excess air, which leads to failure of stoichiometric mixture composition. It is practically impossible to ignite such a mixture, as there is a sharp increase in the volume of oxygen molecules. And it is very difficult to pierce these molecules with a spark, as you know from physics course.

Check for air intake with a smoke generator. They are at the diagnosticians at service stations. You can make a homemade device out of plastic bottles and a cigarette. There is a lot of information about them on the web. You need to check for leakage when the engine is cold.

Basically, the leakage occurs through the injector seals, which are in the cylinder head or in the intake manifold. There are old methods of diagnosis, with a soap solution spill, but it is very erroneous. But in the absence of anything else, it’s a good help.

The second place in the ranking of leakage is the gasket between the intake manifold and the cylinder head. It is also possible to pour liquid on this place and if there are air bubbles replace the gaskets. The smoke machine is an accurate diagnostic.

There are cases when the manifold cracks inside and it is very hard to find such a crack.

A common area of leakage in the intake system is the purge adsorber circuit. So called tank purging. Hoses, the filter itself, the valve have rubber seals that over time crack, deteriorate, soften and let excess air into the system. To exclude this cause, you can temporarily turn off the purge adsorber system connector on the intake air receiver and observe.

This system is an environmental standard. It is therefore a violation of environmental regulations to pull the hose completely out of the tank!

Ignition skips on the Peugeot 308. what is it?

It is possible to detect spark gaps without diagnostic equipment. Here are the main symptoms:

  • engine is in tailspin;
  • The check light is on;
  • the fan is running all the time;
  • the power decreases sharply and the fuel consumption increases;
  • error message appears.

On Peugeot 308, ignition fault codes start from P1336 (ignition fault, not identified cylinder), in sequence up to P1340 (ignition fault in the 4th cylinder).

There can be many reasons for skipping. from low-quality fuel, to insufficient compression in a particular cylinder. If we have already replaced spark plugs, all is fine with coils, then we measure the compression. Rating is 12.6-13 atm in each cylinder. If the compression is abnormal or one of the cylinders has low compression. this will indicate that the compression rings are laid, it is possible air leakage, malfunction in the gas distribution mechanism.

The problem with the injectors

Errors P1336-P1340 can also occur because of a faulty or clogged injector.

To avoid removing the ramp, you can check the resistance on the injector pins. For this you need a multimeter in resistance measuring mode.

Nominal resistance of the injector is 12.6-12.8 ohms.

It should be checked only in the moment of occurrence of malfunction. If all is all right with the resistance, it remains to flush the injectors. it is better to do it on a flushing stand with a special liquid.

A problem with the timing gear

It is difficult to diagnose and repair timing system problems with your own hands.

This requires removing the block head and doing a visual diagnosis, and measuring the height of the valve lift. For example, the EP6 engine has a valve lift of 0.4 mm at idle. and at high rpm, it’s about 4mm. BMW’s VVTi system is responsible for the phase change, which is quite difficult to figure out.

A common breakdown on 308s is valve seat misalignment or loss of. soot on the valve, which will also cause the above-mentioned errors and symptoms.

engine, starts

Attenuation of air

Air intake can occur in several places:

  • head gasket;
  • Inlet manifold gasket;
  • Leakage through the inlet manifold connections;
  • EGR valve failure or clogging.
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