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Stuck engine: causes, troubleshooting
Stuck engine: causes, troubleshooting

Stuck engine? Immediately check the rotation of the crankshaft by hand or starter. The causes of failure can be of mechanical and physical origin. The latter event occurs more often due to overheating due to a lack of oil or foreign inclusions.

Problem detected

In the first minute it is not always clear what exactly happened - another unit is not spinning or the engine is jammed. What to do if the starter does not turn the crankshaft? Trying to start with a simple visual inspection of the engine compartment.

jammed engine

Trying to determine if the engine could jam from:

  • Overheating (this can only be felt immediately after it stops).
  • Lack of lubrication (check the level).
  • Examine the external condition of all nodes, it is important to notice the presence of leaks or mechanical damage. The coolant level is measured. Without it, the engine will also overheat.

If the engine is jammed, then you should check the operation of the entire cooling system. Boiling liquid indicates a faulty priming pump. The pump is responsible forcirculation, without this, the temperature in the engine channels rises.

Why isn't the crankshaft turning?

Stuck engine - manually checked: is it possible to break the crankshaft. If this does not happen, then you can turn on any transmission of the box and try to push the car. It is strictly forbidden to pull the machine with a cable. This could cause even more damage.

jammed engine causes

Stuck engine - it is recommended to unscrew the candles and repeat attempts to crank the crankshaft manually. The reasons may be third-party objects in the wells or crumbled liners, which is a rather rare case. The fluid in the pistons will be squeezed out when the spark plugs are removed, and foreign objects and dirt can be seen through the inch hole.

Additional sources of failure

If after elementary checks it remains unclear why the engine jammed, it is recommended to recall previous events. Have you added oil before, if so, what quality. Two oils of different types and viscosities could easily coagulate and foam.

can the engine seize

Adding low-quality additives to engine oil will also adversely affect the operation of its components. Similar consequences will occur if oils not recommended by the manufacturer are used.

Fuel affects the condition of pistons and rings. Too high an octane number leads to their deformation, and because of this, the engine has jammed more than once. The reasons for the failure may also bemalfunction of the ignition system.

Irregularities at work

If the engine is jammed, also check the moment of spark formation in the engine. Each moment of ignition of the fuel must occur when it is at the top point. If this is delayed, the movement of the crankshaft will be resisted when the other piston is pushed down with the force due to the mixture.

jammed engine what to do

Similar problems occur when fuel is injected into the piston at the wrong time, when the spark is supplied correctly. It is better to carry out diagnostics of these knots in the conditions of car service on the modern equipment. It is also not allowed to drive in hot weather with a defective cooling fan.

The oil pump is mechanically connected to the crankshaft. The sufficiency of getting oil on the rubbing surfaces is checked. It turns out to diagnose hidden defects, alas, when the engine has already jammed. VAZ has similar problems with insufficient car care.

Oil starvation inside the engine occurs when the level in the crankcase is constantly low. The crankshaft should practically bathe in protective additives. Otherwise, the metal expands under the influence of temperature. Therefore, delaying with periodic oil changes is strictly not recommended.

Ridiculous cases

If the engine is seized, signs of thickened oil may indicate that sugar has entered the system. Similar consequences occur when a raw egg is stirred, which, when the motor is running, will definitely heat up and brew all the channels. Howhow the last substance enters the system - known only to the owner of the car.

why is the engine stuck

Sugar can be poured by ill-wishers through the filling hatch into the fuel. There are many substances that change the composition of the oil. It happens that a driver may mistakenly pour a mixture that is deadly for iron into the engine neck.

A malfunction when coolant penetrates the oil can also lead to wedging of rubbing metals. This can be seen when measuring the level on the dipstick. The changed composition is noticeable to the eye and to the touch: by color, viscosity, by the presence of foam. A whitish tint indicates a loss of oil quality.


Engine wedge can be prevented by carefully maintaining the car. Periodic inspections and constant monitoring of the performance of monitoring and signaling units helps to avoid the option when operation continues in case of malfunctions. It is important to notice the following conditions in time:

  • visually low coolant level;
  • visually low oil level in crankcase;
  • lack of oil pressure sensor operation;
  • deviations in economizer readings;
  • changing engine thrust;
  • extraneous sounds in the car: knocks, hum, ringing, rattle.

Immediate diagnostics in a car service of suspiciously working components will save you from costly overhaul. It is recommended to stop operation if you are not sure about the he alth of the engine.

Miscellaneous occasions

Procedure forengine failure depends on when it happened. If the car stopped abruptly in motion, then most likely a mechanical hit of a foreign body or a breakdown of the rotating assembly. It is recommended to look for a faulty place and abandon further attempts to turn the engine by force.

stuck engine signs

After a long drive, the engine was turned off. And the next morning it is impossible to scroll manually. High chance of clotted oil. Major renovation required. Most likely, it will be possible to rotate the crankshaft, but with a lot of effort.

If the car stood for a long time and it was necessary to start it, but the engine does not turn, it is recommended to force the rotation through the gearbox with a cable or manually. Often this happens in cold weather, when mineral oil thickens a lot. There is no malfunction, you just need to warm up the oil or wait for warm weather.

How's it going?

Most often, foreign objects enter through the carburetor flaps. Dust and larger inclusions also get there when cracks form on the air intake path. It is required to check the integrity of the pipes, the cleanliness of the filter.

After repairing the carburetor, a loose part could fall into the engine wells. Similar consequences can be obtained with careless mounting of the engine head with valves. It would be useful to check the purity of the lubricant by draining it from the crankcase. But the latest work is carried out in a pit in a service environment.

Broken belt

A deplorable result is observed when the timing belt or chain breaks. Often evenbending cylinder blocks. At the moment of impact, the valve covers break. As a result, the engine has to be overhauled.

jammed motor

If not properly repaired, broken parts may remain in the crankcase, under some circumstances they will again fall into the next engine wedge. A loose damper can also get under the timing belt or chain. Valves and cylinder blocks are deformed under incorrect operating conditions.

There are scuffs that constantly touch the moving metal. At some point, when the wear becomes large enough, the final wedging occurs, and the crankshaft can no longer be rotated.

Mechanical wear

The main cause of the wedge in domestic cars are internal loose mounts in the engine due to poor-quality lubrication and its non-periodic replacement. The nuts of the main bearings, the timing belt tensioner, the fastening of the connecting rod head can loosen. After a makeshift overhaul, the retaining ring may come out of the piston. The reason for this is non-standard parts.

A broken valve can be checked visually by removing the engine cover. Often a spring flies out or the valve itself bends when the timing belt breaks. Malfunctions occur when the cylinder head is tightened without a torque wrench, when a crack appears in the walls due to overvoltage and, accordingly, the pressure on the lubricant drops. The likelihood of an engine stall increases with excessive loads while driving.

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