Skip the auto shop - Our mechanics make house calls

Q: Car Overheating

asked by on

I just topped off my coolant, but my car temp is still getting very high and close to over heating within two miles of starting to drive. There is no noise from the water pump. Is is possible that I just need to replace the thermostat?

If your coolant level was really low and you added coolant you could have air trapped in the system that creates a block to normal circulation. There are little weep holes set high in the coolant "piping" that allow you to purge air as you add coolant. Normally, these are opened when you are refilling a totally empty system in order to avoid trapping air and creating a blockage.

A malfunctioning thermostat is a common cause of overheating but before you condemn the thermostat make sure radiator electric fan(s) are fully functional, radiator is not obstructed with external debris, radiator is not internally plugged with sludge, and you don’t have a collapsed rubber coolant hose. There are some checks a mechanic can do to try to assess flow rate to see if thermostat is not open and/or radiator is plugged.

Note that if car is seriously overheating, you can easily cause significant damage to the engine via warping of the head and/or block. If it’s overheating at all, the prudent thing is to not drive the car until it is repaired; that will help you avoid needless additional problems. YourMechanic can evaluate the overheating situation for you and will be pleased to do so.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Car overheats and smokes

The overheating could be from one or more problems on this particular engine and vehicle: the water pump, radiator, or thermostat may be bad or leaking. If the smoke is coming from the tailpipe, you likely have blown a head...

Q: I don't have any clue what happened!!!

Hello. The squeaky drive belt was the cause of the problem. It has likely failed. The water pump, which is driven by the drive belt, is responsible for the flow of coolant through the cooling system and the heater core....

Q: Heater not working reliably, is it caused by a bad thermostat?

From what you've described, it sounds like you have a stuck open thermostat. I'd recommend replacing the thermostat to see if this is the cause of the slow heat up of the vehicle since it's a relatively quick repair. In...

Related articles

What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the...
What are the Car Pool Rules in Hawaii?
Hawaii is widely regarded as a land of vacation and relaxation, and as such, its scenic roads and routes are far better known than the state’s freeways. But, as with all...