Today we will give you complete information about how to diagnose overheating engine, which you can easily fix the problem of overheating.

The problem of overheating is seen in 50 out of 100 cars and there are many different causes of overheating which can be very difficult for a mechanic to diagnose.

Looking at these problems, we will tell you different ways to fix car overheating, with the help of which you can check the problem of overheating.

how to diagnose overheating engine diesel and petrol

Know how to check the problem of overheating

(1) . coolant level check

Whenever your car is overheating, the first thing you have to do is to check the coolant level because the main reason for car overheating is the low coolant level.

So first check the coolant in the radiator, if the coolant level is low, then after the car cools down, complete the coolant level in it and start the car and check if the coolant level is fine, then check further.

(2) . radiator cap check

After checking the coolant level, you have to check the radiator cap because in most of the cars we have seen that the radiator cap leaks due to which air is formed in the coolant.

When air is formed in the coolant, the coolant heats up but the radiator fan does not run, due to which the engine of the car is overheating and we do not know the problem.

(3) . radiator fan check

If the radiator cap is correct and the coolant level is also correct, then you have to check the radiator fan because in most of the cars, the fuse of the fan gets damaged due to which the fan stops.

When this happens, the engine is overheating but the fan is not on, which does not cool down the engine and the problem becomes worse, there are some reasons for the radiator fan to stop like

(1) . bad fuse and relay

(2) . bad wire and connector

(3) . bad coolant tempecature switch

(4) . low coolant level

(5) . bad fan module

(6) . bad radiator fan

If the radiator fan is not running then you can check all these things

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(4) . check leakage

Leakage is one of the main reasons for car overheating, so after checking the radiator fan, you have to check the coolant leakage.

You have to check all the pipes properly, there is no leak from anywhere or there is no chock due to which coolant is not being supplied or air is being created in the coolant, so check all the pipes.

(5) . check thermostat valve

A major reason for the problem of car overheating is the thermostat valve because it works to cool the engine and helps to run the radiator fan.

If there is a problem of overheating in the car, then you have to check the thermostat valve, it is not damaged because the spring of thermostat valve is very bad and 60% of the car heats due to thermostat valve.

(6) . check coolant tempecature switch

In case of overheating problem, you must check the coolant temperature switch because this switch works to run the radiator fan.

And when this switch is bad, the fan is not on, the easy way to check this switch is to remove the connector of this switch and start the car and check whether the fan is running or not, if the fan is not on, then this switch is bad, but in some cars the system is slightly different, so check the switch differently.

(7) . check water pump

If everything seems fine to you and there is no coolant leak, then you should check the water pump because when the water pump is bad, the car starts overheating after driving some distance.

For this, you remove the pipe in the coolant bottle and start the car and check the supply of coolant in it, if coolant is coming, then the water pump is correct, if coolant does not come, then there is a problem with the water pump.

(8) . check heater coil

After checking everything, it is necessary to check the heater coil installed in the dashboard because the supply of coolant in your car engine goes through the engine to the heater coil and comes back from there.

Many times the heater coil gets choked or leaks due to the use of water instead of coolant, due to which the engine starts overheating, so check the heater coil.

(9) . check radiator

If the car is overheating again and again and everything is fine then you should check the radiator once because the radiator gets chocked.

We have seen many cars in which there is radiator chock, the pipe of the radiator becomes chocked, when this happens, you should get the radiator cleaned.

If your car is overheating, then you have to take care of all the things mentioned above and check all the parts mentioned above.


Hope you have come to know about how to diagnose overheating engine and now you will not have any problem related to it, if you have problem related to overheating, then you can comment, we will help you completely and solve your problem.

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Know the answers to some questions

Q. What to do when the engine is overheating?

ans. After the engine is overheating, you should first cool the engine, do not immediately pour water into the radiator, pour water into the radiator only after the engine has cooled down.

Q. How to detect engine overheat while driving a car?

ans. Whenever the engine of a car is overheating, then the warning light turns on in the dashboard of that car, through which we come to know that the engine has overheated, along with it, other symptoms also appear.