Q: Can a bad thermostat cause me to have to keep putting coolant in my car?

asked by on

My car runs hot sometimes. The temperature guage will go all the way up and come back down to normal. Also I smell the coolant sometimes when I get out my car and I never had that problem before. On some days it runs hot but most days it is fine.

My car has 161000 miles.
My car has an automatic transmission.

Hi, thanks for writing in. The thermostat in the engine cooling system is a valve that opens and closes as engine temperature fluctuates. The purpose of the valve is to keep the engine operating temperature at a relatively constant, optimal level of roughly 200 degrees. Keeping it at that temperature maximizes the efficiency of the engine while preventing damage from too high a temperature. If the thermostat is malfunctioning, for example sticking, that could cause the car to overheat. The odor of coolant is probably due to very hot coolant overflowing into the reservoir, and perhaps even out of the reservoir, on those occasions when the engine is operating too hot. Overheating is not good for the engine. If severe, it can cause quite a bit of damage actually, including things like a warped cylinder head or engine block. If you are having to add coolant more than once or twice a year, you have a leak somewhere in the cooling system. If the engine is overheating, the best to do is get the cause identified and repaired. YourMechanic specializes in just that sort of diagnostic and would be glad to help you with this issue so that you can get your car repaired and running normally. Our technicians can come directly to your home or office to inspect your car for you.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1,000 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

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!
  1. Home
  2. Questions
  3. Can a bad thermostat cause me to have to keep putting coolant in my car?

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: My 2012 Scion tC will over rev when I'm trying to accelerate.

If your clutch is slipping you will be able to hear the engine rev, and the tachometer rise without any apparent acceleration of the car. It tends to happen in the higher gears because that is when the load on...

Q: Method used to replace clutch fluid

There are two different methods that can be used. One is to use pressure on the master cylinder with fluid and push new fluid through the system. The other method is to use a vacuum at the clutch slave cylinder...

Q: is it possible to tamper digital odometer readings?

Hello. On this vehicle it is not typically possible to adjust the mileage reading on the dash. If the instrument panel was replaced then that would contain a new mileage read out but the vehicles on board computer would always...

Related articles

How Long Does a Distributor O Ring Last?
The distributor is part of the ignition system in your vehicle and its purpose is to route high voltage from the ignition coil to the spark plug. The spark plug then...
Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...
P2428 OBD-II Trouble Code: Exhaust Gas Temperature Too High Bank 1
P2428 code definition A P2428 trouble code signifies that the PCM has detected a problem in the exhaust gas temperature sensor circuit in bank 1, which subsequently contains the number one...