What temperature should a car engine run at?

This blog post will answer the question, ‘What temperature should a car engine run at?’, and cover topics like state of the engine when the temperature is exceeded, causes of this state, symptoms of this state, different temperature gauge conditions, and steps to take to tackle this problem.

What temperature should a car engine run at?

The normal or optimal operating temperature of a car engine should be somewhere between 190-225 degrees. This temperature can undergo rapid fluctuations, depending on the environment the car is being driven in.

State of the engine when the temperature is exceeded

Exceeding the optimal operating temperature the car engine should run on, can cause it to overheat. This is a serious issue and can cause further damage to the car if not fixed with immediate effect.

An overheating engine can cause most of its crucial components to fail. It mainly happens due to a coolant leakage from the radiator or a thermostat gone wrong. A defective water pump or a cooling fan can also cause this problem.

Causes of this state

The following are the various causes that contribute to a car engine overheating.

Leakage of coolant

The cooling system of the engine is responsible for maintaining a normal operating temperature for the engine and for sucking away all the heat. It comprises the water pump, radiator, coolant hoses, a head gasket, and a thermostat.

These components are crucial for helping the cooling system function optimally and with time and frequent use they can get worn out or even broken, thus causing the coolant to leak out everywhere and hindering the cooling of the engine.

Obstructed hose pipes

In the event of no coolant leakage, the problem might lie in the hose pipes that have been clogged or obstructed due to the accumulated dirt and other debris from the roads, thus hindering the flow of coolant to the engine.

Defective water pump

The water pump is responsible for transporting the coolant material to the engine and can get damaged or worn out after frequent use. It is advisable to take a look at the bump shaft and impeller vanes of the water pump if they are working optimally.

Defective radiator

The radiator is another vital component of the car’s cooling system and helps to suck out the heat from the engine coolant, thus allowing it to be recirculated to the engine to cool it.

At times the radiator can face a broken fan or clogged channels and thus hinder the escape of the heat from the coolant thus keeping both the coolant and the engine hot. The radiator cap might also be loose or broken.

Insufficient oil levels

Oils that are meant for the car act as both a lubricant for moving components and a cooling agent for the internal temperatures of the engine.

Low oil levels will result in lower cooling being done for the engine and all its components and also cause a lot of friction between moving components as they rub against each other without any lubrication.

Faulty thermostat

The thermostat is responsible for opening and closing whenever needed to keep the engine at a normal operating temperature. If it gets stuck in either an open or closed position, it can cause the engine to overheat.

Symptoms of this state

These are the following symptoms to identify an overheating engine.

The temperature gauge reads red

The temperature gauge is vital for determining the car temperature and it consists of a needle that points to the current state of the car. The needle should almost always stay clear of the red area that indicates the car is overheating.

Fumes from under the hood

The car engine when overheated will cause fumes to radiate out of the engine hood, that might be caused due to a faulty radiator that prevents the heat from escaping from the engine coolant.

Distinct smell

A car engine is made up of different components like metal, plastic, and rubber. In case of the engine overheating, a distinct burning smell is present inside the cabin and should be tended to immediately.

Weak engine performance

An overheating engine will result in a drop in engine performance, and trying to accelerate or get more out of the car will result in no results as the car will fail to meet any of the demands.

Different temperature gauge conditions

These are some different temperature gauge conditions.

A fluctuating temperature gauge

These are the following factors affecting a fluctuating temperature gauge:

  •  A damaged or broken thermostat needs to be replaced immediately 
  • A defective radiator is another factor and is indicated by unusual noises
  • A damaged head gasket is indicated by cracks on its surface and results in the leakage of the coolant into the engine

The temperature gauge reads high

The factors affecting a high-temperature reading are:

  • An overheating engine
  • Leakage of coolant
  • Faulty thermostat
  • Defective water pump

The temperature gauge reads low

A temperature gauge under normal working conditions can only read low when the engine is turned off. If it reads low even while the engine is running or the car is in motion, and fumes appear from the engine, the temperature gauge itself needs a replacement.

Steps to tackle this problem

These are the following steps to be taken while trying to tackle this problem:

  • The car must be parked in a cool and enclosed space immediately to help in cooling it off
  • The air conditioner must be turned off and switched to heater mode, as the heater will allow sucking in the excess heat from the car
  • In case of low coolant or oil levels, they must be added immediately.
  • Check the thermostat if it is stuck open or closed
  • Restart the engine and try to drive slowly, pull over in case of the temperature gauge reads red again
  • For a deeper analysis of the problem, it is advisable to consult a professional mechanic or have the car towed to the nearest automotive repair shop.

Research has shown the different types of coolants and the various factors that need to be taken into consideration when selecting the best engine coolant for your car.

Other articles about Mercedes Benz you may be interested in

What are the reasons behind my car engine sputtering when starting?

How to fix a car engine shutting off when idle?

Why is my car engine hot but not overheating?


This blog post addressed the question, ‘What temperature should a car engine run at?’

We understood the condition of the engine if it runs at a temperature exceeding the threshold and also came across the various causes for the condition to occur. Furthermore, the symptoms of this condition and the various steps to be taken to solve this issue have also been discussed. Please feel free to comment on the content or ask any questions in the comments section below.

Frequently Asked Questions (FAQs): What temperature should a car engine run at?

What temperature is considered overheating in a car?

An engine with an operating temperature of more than 220F is considered to be an overheating engine.

What temp is too high for coolant?

The normal operating temperature of the engine coolant should be somewhere between 235-250F.

Why does my engine feel so hot?

The primary reasons behind a car engine feeling hot are a defective water pump, damaged head gasket, a faulty thermostat, or, insufficient coolant levels.