I have a '99 Intrigue with 3800 motor that is overheating.
First time my daughter was on her way back to school. Overheat, got it towed in. They couldn't find anything so they replaced the thermostat and no more Deathcool.
I drove it around and it seemed fine.
Then before my daughter could get home from college to pick it up, my girlfriend took it and it overheated on her. She let it cool and drove it home. Took it to the shop. Nothing wrong.
So... I took it out. Took it to the shopping center, let the fan cycle. It would idle for an hour, no problem. Took it on the highway for about 15 minutes at high speed. (Yeah, really high speed) The gauge went up about 2 needle widths, but no problem.
My daughter was supposed to take it back to school but just in case, I took it out and went for a 1 hour or so drive. Not at high speed, just on the highway. It worked fine for about 50 minutes. At times the gauge would climb slightly, about 2 or so needle widths, then come down.
Then it shot up. In about a period of 2 minutes it crept up to pin at full hot. I pulled over. No steam, but the gauge was as far as it could go. What was really bizarre was that the hoses were soft and not overly hot. In fact, I shut the engine off and expected a boil-over. Nothing. About 5 minutes later I popped the cap and there was fluid. It wasn't low. I even felt the water pump on the engine block, and it was hot, but no so hot I couldn't touch it. And again, no boil-out from reducing the pressure, and the fluids were ok.
So, I'd say it was just a gauge or sensor. Except that when I got back in the car there was an ADDITIONAL red light on at the temp gauge. I thought sensor/gauge. But when I tried to drive the vehicle it would get to about 3000rpm as I was pulling on the highway and then 'shut off'. The ignition would die.
I had it towed in.
And of course now it's working perfectly. Sitting there idling and cycling the fans, for an hour or longer. And even driving around town it works fine.
It only seems to be triggered by SUSTAINED highway driving.
I'm about to try to get a scan tool and leave it hooked up and take it back out on the highway. Would that tell me anything more than I know (or don't know) already?
Any ideas?
Mike