Hi All

I just bought a 2005 Uplander with 97k (fully loaded). The engine and transmission seem good. The only thing that i observed was the Temp Gauge on the dash: The needle stays about %52 to the right-hot side,but suddenly it goes back to 42-45% range. In other words, the needle goes back and forth between 42%-52%.I don't know what is causing this, but i don't think it is normal

When i bought car, the coolant level was low in reservoir so I added some coolant, but i could not remember how much i added so i can't say if the car has lost some coolant or not.The heat works fine

Anybody experienced this yet?

Thanks

 

When was coolant last changed? Was thermostat changed?
Does it have Dex-Cool coolant?
Did you add Dex-Cool coolant to reservoir?
Does the temp gauge move abruptly or slowly from 42-52% ?
Did you test drive vehicle before buying it? Does it have a warranty?

 

I just bought the car from an auction-no warranty.I also have no maintenance record for the van.Yes, I was able to drive it before i bought. I knew the temp gauge was not normal, but i let the car idle about 20 minutes and drove it 15-20 miles or so, no overheating-never passed 52%.The color of the coolant in the reservoir was red, so i don't know if it was Dex-Coolant...I added 50/50 prinstone coolant.

 

Dex-Cool will not mix with ordinary antifreeze, it will gel up and plug the system.
Since you don't know the history of the van I would drain and flush the system and refill with fresh longlife coolant. A pressure test of the cooling system would tell if there are leaks and it would be a good time to install a new thermostat.
Good luck.

 

Thanks for the advice. Can i use prestone 50/50 coolant. I heard dex-coolant may create some problems for the van. Should i get it drained or flushed, my uplander has 97k.

 

when the thermostat opens there will be a slight drop in the guage reading. Could that be what your describing?

The upper rad hose will go from ambient to hot when this happens so you could check by having someone watch the guage and someone feel for the temp change in the hose.

also...these vehicles are bad for air pockets in the cooling system; any low heat output at idle but ok at 2000rpm issues?

 

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I would advise you to take the vehicle in for an inspection. A certified technician will be able to offer more information and possible resolutions, after a physical inspection.

Please keep us posted.

If you have additional questions, please feel free to contact me.

Louis
GM Customer Service

 

This has to have something to do with the thermostat, but it looks like the thermostat opens a little bit late, but yes there is a slight drop. I ll check the air tomorrow to see if i have the low heat problem

 

Just like Papa Bear says, don't use anything but Dex-cool coolant for GM vehicles. If you mix the yellow and orange coolants, it will clog up in the cores of the engine. So, flush it out since you already have done so. Recently, I purchase a 2005 Uplander, 74k. I also have the same issue with the thermosat. There was a few warm days and then a few 20 degree days. The engine overheat light came on. I think the theromostat is just sticking since there is some miles on it. Everything runs good. I have had it over a year. I bought a new thermostat but just haven't changed it yet since it seems a pain to do. I just changed the plugs. What a pain that is to tilt the engine forward, remove the coil pack, just to get to 1,3,and 5. After that project, I have to take a few weeks off before I go back. And I would reccommend changing the plugs too. If you change the serpentine belt, instal a new tensioner pulley on too. I just did that too. You will have to loosen all three screws on the window washer reservore to get some room to put the bolt in with you wrench.