I have a 2000 Intrigue with 80K. A few days ok I noticed the temp gauge reading over half and up to 3/4. Didn't overheat that I could tell. Fluid was changed before I got the car according to main records.

The temp gauge comes down if you shift down from D to 3rd an increase RPMs. Temperature rises as your driving even at speed. Only think that seems to bring it down is downshifting an increasing RPMs or it just drops on its own all of a sudden only to build right back up.

Belt seems ok. Had thoughts of changing fluid and thermostat. I thought I read of a new design thermostat housing to correct an overheating condition in winter. Do you need to change the housing or can just themostat be replaced? Do you need to go to dealer to get updated housing? Looks like you need to use care in changing the thermostat as it sits right above the alternator. Is there a block drain plug and a plug on the radiator? I know where the bleed screw is for the radiator.

Might there be another issue with say the water pump?

Craig

waterpump impeller blades are bad/gone. Good time to get rid of thedexcool

I was thinking it might be the water pump. Guess it is time for a complete overhaul of the cooling system. Thermostat, water pump and new fluid.

What is recommended coolant for the 3.5?

On the thermostat there was a winter issue and I have this part number.

Enhanced thermostat 12570248

Is that thermostat only available at GM?

Craig

I ordered the Enhanced thermostat 12570248 from a local GM dealer. Going to flush out fluid and try thermostat first. If that doesn't correct it I will change outt he water pump next. Will just put distilled water in to test thermostat in case I need to drain again to replace water pump.

Couple questions.

1. Is there more then one gasket for the thermostat? NAPA lists a gasket and a seal. I asked dealer to get what I need for the thermostat.

2. What is the recommended coolant to put back in?

Craig

I get a lot of folks who tell me they are overheating- I say how do you know? is there coolant boiling out? they say no-- the temp gage is higher than normal.. I say well maybe it is okay- since you are coming out of winter and you are not running your a/c yet- the cooling fans wait until engine temp is about 227 degf to come on- and don't come on at all while driving-- all by design-- so is your engine really hot? the true answer comes by using a scan tool to see what the ECM says the coolant temp is- just because a panel guage runs a little hotter than you are used to does not mean you are overheating. Turn on the a/c and see if temp guage returns to normal (because the cooling fans are now on)-- or answer this-- are cooling fans running when your temp gage is higher than normal? wait a few minutes and see if they come on....You may not really be overheating-- is my point-- just some things to consider.....before you spend a bunch of money.....

Good points and I thought about that. Temp gauges never goes above 3/4. I tried connected my scan tool. I use AutoEnginuity package which is loaded on my laptop. Has worked before and on other cars and trucks. I did have trouble with the scan tool on the Olds disconnecting while driving but it worked sitting still. I connected the scan tool to look at water temp but it wouldn't connect at all. Said it was seeing the cars connected and it said to make sure the connector was being powered. Checked some fuses and they all were fine.

What is interesting is car gauge climbs even on cool days going 60mph. Figured one wouldn't need the fans for that. If I drop out of drive and increase RPMs the gauge comes right down and fast.

Would like to figure out why my scan tools doesn't work on the Olds. Going to try different laptop to rule out the USB ports.

I figure it can't hurt to change the thermostat to the newer part number and fush system anyway.

Craig

Put in the enhanced GM thermostat the other day. Problem solved. Gauge now sits steady just above the quarter mark.

Fluid that came out was very clean. Had bit of issue with the drain plug on the radiator. Couldn't figure out how to loosen it. The end of my quarter inch socket entension fit in the end and I turned fitting a bit to left and pulled out on it.

Craig

I never open drain plugs on radiators- have been burnt too many times- they can snap off, strip, break-- I always siphon-- much cleaner way of containing used coolant-- or pull off a radiator hose.....glad you got it where you want it..