Temperature needle rises to red zone?

Tiny
MEY549
  • MEMBER
  • 2000 HONDA CIVIC
  • 4 CYL
  • 2WD
  • AUTOMATIC
  • 150,000 MILES
Needle rises to red zone. Rad and fan ok. Thermostat was changed 9 months ago. When putting heat on it lowers needle. Is the problem a sensor or the thermostat?
Wednesday, August 6th, 2008 AT 6:58 AM

1 Reply

Tiny
SQM
  • MECHANIC
  • 6,383 POSTS
Hello,

It is possible to have the thermostat failed at the stuck closed position, which is triggering the engine to overheat.
Another possibility is that the water pump is not circulating coolant properly, which could be due to a bad impeller.

If the thermostat is stuck closed, you will have a significant temperature difference between the upper and lower radiator hose, when the engine is at operating temperature or above.

https://www.2carpros.com/articles/how-an-engine-thermostat-works
https://www.2carpros.com/articles/replace-thermostat

Here is a helpful guide on water pump:

https://www.2carpros.com/articles/water-pump-replacement

I have attached diagrams for your reference.

Please let me know if you have any questions.
Thank you.
Was this
answer
helpful?
Yes
No
Tuesday, February 1st, 2022 AT 10:31 PM

Please login or register to post a reply.

Sponsored links