99 Grand Caravan temp problems

[garyrowland]

99 Grand Caravan, ~100K miles. Coolant level is OK.

When I first noticed the problem, while driving my caravan for about 10 minutes or so, the temp gauge would start climbing and would make it almost to hot (but no idiot light), then will drop back down to the normal range and then be fine for the remainder of the trip (even if I was driving for an hour). It didn't seem to make any difference if the a/c was on or not. It also seems as though I would hear some sort of noise coming from under the dash (like a mechanical linkage-type noise?) just before the temp would start dropping again.

The problem seems to be getting worse- this morning I drove it for 10 minutes (outside temp was about 48), then stopped and let it idle for 2 minutes. Neither the heater or a/c was running. The temp gauge started climbing to Hot and I got an idiot light this time. I didn't keep driving to see if it would come down as I was afraid of overheating it too long.

Any ideas? What do I check/try first? My first thought was thermostat, but after reading some of the posts here, I thought I'd better get some expert advice!!

Thanks for any info you can share!

[yogi_123rd]

Your problem is either with the thermostat or with the cooling fans not coming on.

[B33p3r]

Fans are easy enough to check. If the temp gauge is halfway and climbing, your fans should be on. If they aren't then you have a fan problem. If they are on but the temp keeps going, then you probably have a sticking thermostat. Easy enough to replace.

[garyrowland]

Yogi and others- thanks for the info! I'll let you know what I find out...

Thanks again.

[vipergg]

Originally Posted by garyrowland

99 Grand Caravan, ~100K miles. Coolant level is OK.

When I first noticed the problem, while driving my caravan for about 10 minutes or so, the temp gauge would start climbing and would make it almost to hot (but no idiot light), then will drop back down to the normal range and then be fine for the remainder of the trip (even if I was driving for an hour). It didn't seem to make any difference if the a/c was on or not. It also seems as though I would hear some sort of noise coming from under the dash (like a mechanical linkage-type noise?) just before the temp would start dropping again.

The problem seems to be getting worse- this morning I drove it for 10 minutes (outside temp was about 48), then stopped and let it idle for 2 minutes. Neither the heater or a/c was running. The temp gauge started climbing to Hot and I got an idiot light this time. I didn't keep driving to see if it would come down as I was afraid of overheating it too long.

Any ideas? What do I check/try first? My first thought was thermostat, but after reading some of the posts here, I thought I'd better get some expert advice!!

Thanks for any info you can share!

Replace the thermostat , it is sticking closed until it gets real hot, had the same thing happen on a old sundance I used to have , fixed it right up.