I have a 2000 Chevy Impala. My temp gauge goes down when I'm on the highway and goes up when in city traffic. What is normal temp? ANd what can be wrong. Please help me!!

You likely need to replace the radiator or have it rodded. Phosphate scale is likely plugging some of the cooling passage ways in the radiator. Once you get the problem solved, only use a 50/50 mixture of the recommended antifreeze (likely DexCool) and distilled water.

This link should help:

https://www.askmehelpdesk.com/cars-t...tml#post235973

Ensure the radiator fan works properly. If not read this link:

https://www.askmehelpdesk.com/cars-t...ml#post1642158

Don't postpone getting the problem fixed. Engine overheating often results in warped aluminum heads, blown head gaskets, and damaged valves ($2,800).

Quote:

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Originally Posted by TxGreaseMonkey

You likely need to replace the radiator or have it rodded. Phosphate scale is likely plugging some of the cooling passage ways in the radiator. Once you get the problem solved, only use a 50/50 mixture of the recommended antifreeze (likely DexCool) and distilled water.

This link should help:

https://www.askmehelpdesk.com/cars-t...tml#post235973

Ensure the radiator fan works properly. If not read this link:

https://www.askmehelpdesk.com/cars-t...ml#post1642158

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Does it cost a lot to have it rodded? Should I take it to a radiator shop? Thanks for all your help!

I don't know what they would charge to rod a radiator. New radiators are not usually that expensive. It may be that it wouldn't be much more expensive to install a new one. Call around and get prices. Just don't wait.. . We have way too many overheating disasters on this site.

I would also add that there may be air in your cooling system. I had a 1985 Plymouth 4 cylinder and the temp gauge would go up really high for a minute, then drop to normal after running engine fast, or just driving. I did not know, but I was delivering the engine a slow death, and eventually had a blow head gasket.

I should clarify that my Plymouth's cooling system was never properly purged of air when the coolant was last flushed, and that is what caused the fluctuation of temp gauge and eventual engine troubles.