I have a 1994 Land Rover Discovery with 126,000 miles. I just had the radiator flushed, but it is still running hot when the A/C is on and in stop in go traffic. It doesn't run hot if the A/C isn't running or on the freeway. Before I take it in, are there any other services that can be done to help it run cooler? I recently had the water pump replaced. Thanks for any info and help.

Dareck

 

Have you checked your cooling fans, are they both working? Have you checked to see if you have air trapped in the engine? Does your truck blow hot air at an idle with the heater on, or do you have to raise the idle for the heater to work?
Mike

 

Two things to check first, the electric cooling fans should be running always while ac is on which is a relay turned on through the ac system, and second is to make sureyour termosat is good, with 126k on it would not be a bad idea to change it. I would consider adding water wetter (at autozone)or simullar item to see if it helps. do you loose any water? if so maybe you have a small crack in a hose or something that is causing it to get air in the system

 

Thanks for the replies.

Last night I ran the Discovery with the overflow cap off and watched for air bubbles (is there a better way to check?). After about 5 minutes about two ping pong size air bubbles came out and some smaller ones. I drove it around some today, not much, but I had the a/c on recirculate going full blast and most of it was stop and go traffic. The temp gauge didn't go much past half way. Hopefully that was the problem. I am going to go through my records, the previous owner kept meticulous records to see if or when the tstat was replaced. How often should they be replaced? The electric fans are working and I feel resistance when trying to spin the other. I will check to see if the heater is working at idle if it isn't, what would cause that? Also, I haven't noticed a lose of coolant, but I will keep checking to make sure.

Thanks again,
Dareck

 

The heater not working at idle would indicate trapped air in the system, which you seemed to have found there was some so that could very well be the problem. If that air bubble was were the temp sensor was it would cause the sensor to get hotter because it is not contacting the water, this would make the gauge read high, the engine itself may or may not actually be getting hotter in reallity. I have had some cars that cannot have any air bubles or they over heat and others that did not but the gauge would show it as hot till the bubble moved around