How to repair a 2003 Chevy Impala cooling system.

Have you checked the temperature sending unit for accurate readings?

I agree with Bmark,the only other thing that may be doing this if the guage is right,would be internal intake gasket or head gasket.

He (Sorry, I used the editorial we in the question as I am just doing the typing-husband is on the phone and I am relaying his question) said that he didn't test it but that he feels sure it is not accurate as it can read 260 and the engine doesn't feel hot yet at other times the engine is extremely hot and the hot signal does not even come on. At times the hot signal comes on yet drive another few blocks and it goes back down to normal. I do know for a fact that I have to put water in the radiator every time I drive the car. I can run to the store less than a mile away and by the time I get back the water is gone. We can't figure out where the water is going. It was leaking from the gasket on the thermostat but that was replaced yesterday and the water is still gone.

No leaks that we can see both with the engine running and/or shut off. No water in the oil nor coming out of the tail pipe. No oil in the water - just can't figure this out.

If you are loosing water this fast,i think you may have and internal leak,meaning intake gasket,it may be burning it off through the tail pipe,rev car up,with white rag on tail pipe a few time,s,rag will get damp,if it is this,

So if the gauge is not accurate and the engine is definitely hot than it would be one of those two gaskets?

Is that easier to repair than the head gasket? I sure hope so as my husband and my neighbor are both "shade tree" and I am beginning to wonder if my car will ever be okay. I will try the rag test myself. Be back in just a few minutes. Thank you so much for answering me.

Yes, I just did the white rag test and the rag is wet. I didn't have it tight enough on the tail pipe the first time and when I rev'd up the car it came off. The driveway right behind the car was wet. I put the rag back tighter and rev'd up the car again and the rag did get wet. Not sopping wet but wet not the less. Also when I raced the motor with my foot on the gas pedal the engine was slowing down and speeding back up as if I was taking my foot off and on - but I wasn't. It was doing it on its own. I held my foot steady but the motor kept backing off and then speeding up again.

Wow - good for you. It is so nice of you to help me.

Of my goodness - thank you so much. We have asked everyone around here and no one knew. You are very smart. If he get someone to replace that gasket then will my care be okay?

Im pretty sure that it is the intake,have you pulled the oil stick?And checked it for water?

Yes just yesterday. It doesn't seem to have any water in it.

Good,that is a definate ,,no head gasket problem,it will be the intake gasket,and yes it will fix your car >>>>: )

Bless you! Thank you so much.

Bless you back,and good luck with it.

The original chevy impala ran hot while idling at lights. I had to put a transmission cooler on mine to stop it. The cost is about $250 but well worth it.

I have a 2003 Impala 3.4 Base. I had the same problems. The 2003 was notorious for lower intake gaskets and head gasket problems. I had to replace both. Took care of the problems.