99 Intirgue overheating in idle

When it rains it pours. I just posted a differnet thread last week for a different proble. My daughter's Intirgue has the following proble.

1. Originally the "low fluid" light came on the display panel. I think I added too much coolant because it was spewing out when she got home and shut the car off. There are no obvious leaks anywhere in the system.

2. The car is running hot when idling (just below the top of the gage), so my brother removed the thermostat to see if this made any difference. It didn't......... I'll have to put the thremostat back in (and I'm assuming along with the housing, since it was very difficult to remove the thermostat from the housing). The car still idles hot, and the temp runs at just below half-way when the car is moving ..................

3. Does this mean the thermostat wasn't bad? and we're not sure what to do from here? Could it be the water pump? There is no noise and leakage (at least that is obvious). Could the radiator be clogged? Any thoughts?

Thanks,

Rick

Did you happen to test the thermostat while you had it out? I dont think the thermostat is your problem, since you said it still ran hot even with the thermostat completely removed.

With the thermostat completely out it shouldve at least cooled back down, or if it was from a cold start it wouldve taken forever to warm up.

It could be either the waterpump or the radiator, you might try either flushing the cooling system yourself or having someone else do it for you. That would at least elimnate the clogged system theory.

Are you losing any coolant? I mean once you fill it up to the proper level are you losing any after letting it run for a while then shutting it off?

You also didnt mention which engine you have, Im assuming you have the 3.5 since you said the thermostat was a pain to change...but the 3.8 was still optional in 99.

Not a mechanic myself but I would guess the loss of coolant can be related to the high coolant temperature that might have causing increased pressure in the system and have opened the pressure valve in the reservoir cap, hence coolant spraying out?

I don't see a point why removing the thermostat, since you're saying temperature becomes normal when the car moves at normal speeds, and that means coolant is being sent to the radiator and being cooled off by the air flow, it also means that the thermostat does open at the temperature as supposed. Therefore, in comparason, when the car stands still idling all it lacks is airflow, and that would immediately point me to the cooling fans for their normal operation, which you didn't mention about, before I would look elsewhere.

When it rains it pours. I just posted a differnet thread last week for a different proble. My daughter's Intirgue has the following proble.

1. Originally the "low fluid" light came on the display panel. I think I added too much coolant because it was spewing out when she got home and shut the car off. There are no obvious leaks anywhere in the system.

2. The car is running hot when idling (just below the top of the gage), so my brother removed the thermostat to see if this made any difference. It didn't......... I'll have to put the thremostat back in (and I'm assuming along with the housing, since it was very difficult to remove the thermostat from the housing). The car still idles hot, and the temp runs at just below half-way when the car is moving ..................

3. Does this mean the thermostat wasn't bad? and we're not sure what to do from here? Could it be the water pump? There is no noise and leakage (at least that is obvious). Could the radiator be clogged? Any thoughts?

Thanks,

Rick

I hadnt even thought about the cooling fans, that could definetely be at least part of the problem.

I cant recall at what temperature the fans are supposed to kick on, but from the sound of the temperature youre reaching, they should definetely be running.

They should also run anytime the AC is on, you might want to verify this as well, im not sure if the same circuitry controls the fans kicking on with hot temps, and kicking on when the AC is engaged, but its highly likely.

Do some experimenting and see if your fans are kicking on, and under what circumstances.

Hi everyone, Thanks for all the advice, I really appreciate your time and expertise. I'm still monitoring the situation. Since removing the thermostat as described above, and the "idling hot" issue, I added a bit more coolant and now the car isn't running hot. I'm still watching the fans and they appear to be kicking in and pretty much running all the time (it's been hot here, so the AC is on constantly). The "low fluid" light has not come back on either. The AC still lags a bit before kicking on...... sometimes right away, other times it takes 4 or 5 minutes). In addition, somtimes the display is blank and/or none of the AC controls work, then they all kick on when the AC engages ..... By the way, the area around the thermostat was very clean, and there are no leaks at this point. This is puzzling (at least to me, a very inexperienced person with cars). Does monitoring for now make sense?

Thanks again, Rick

I think you should definetely have the cooling system flushed, either do it yourself or have a mechanic do it. A good honest mechanic shouldnt charge you too much for it, but those are also hard to come by sometimes.