Skip the auto shop - Our mechanics make house calls

Q: Temperature gauge goes up when driving and down when not

asked by on

We got on the freeway and noticed that the heater wasn't working and the temp guage was getting hot and went all the way up we pulled over and put antifreeze in and made sure there was oil. When we would drive it would go up when we stopped at a light it would go down. We noticed antifreeze had leaked out somewhere under the hood probably when it went to hot.

My car has 199000 miles.
My car has a manual transmission.

A: Hello. This suggests you may have a faulty ...

Hello. This suggests you may have a faulty coolant fan relay switch. This is a relay that triggers the cooling fans to come on at predetermined temperatures. When this is not working properly, this can cause the fans to come on intermittently, all the time, or not at all. When they do not come on at all, this will cause the motor to get hot, especially while sitting at a stop since there is no air flowing past the radiator or engine. As you speed up, the air from the speed of the wind will cool it down slightly which is what you notice when your gauge drops. I would recommend having an expert from YourMechanic come to your home to diagnose the overheating issue and let you know what needs repair.

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

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!

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Save up to 30%

Get a quote

What others are asking

Q: I'm wondering what would cause my car not to stay when it is warm , I'm changing all pre and post cat sensors today. No power also

Hello there, a variety of faults can cause your 1996 BMW 740iL to not start when cold and run rough. Without knowing the exact code I can only give general advice. A lean condition can be caused by many faults...

Q: alarm won't stop car won't start

You may want to try closing all the doors, then putting the key in the drivers door lock and locking then unlocking the vehicle. You an also try putting the key in the ignition and trying to start the vehicle....

Q: ive got noise from rear differential and noticed ihave slight movement in nearside shaft.

Hi there: Thanks for writing in to YourMechanic about the noise coming from your rear differential. There are multiple mechanical problems that could be causing your noise, ranging from a bad differential seal to problems with the lateral link. Either...

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...
How to Renew Your Car Registration in Oklahoma(DELETED)
Having your car registered with the Oklahoma Tax Commission is an important part of driving legally in this state. You will need to do this within 30 days of moving to Oklahoma...
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...