Half on temperature gage

[Bill Wilky]

I have a 1999 OLDS Sil van with 3.4 engine. I just had the engines upper and lower intake gaskets replaced with a 195 thermostat installed. Now it reads half when ideling and will go down to 3/8 when driving. I'm being told by the mechanic thats normal. But before the gaskets went bad, it always read at 1/4. The mechanic says if it bothers me that much we can replace the therostat with something lower or just turn on the air conditing and it will kick on the two fans up front on the radiator to cool down to almost the 1/4. The book I looked at does call for 195 degree. So is it normal for this?

[MagicRat]

If you are really concerned, get a real, aftermarket temp gauge, so you can see the actual temp.

FWIW, it sounds as if your old thermostat was a 180 deg. or was malfunctioning. What you describe is normal for many vehicles.

I would suggest drive it for a while. Make sure the overflow tank has coolant in it and the 'drop valve' in your rad cap is working. This will allow the engine to purge itself of any air pockets in the water jacket over time (these sometimes produce an inaccurate reading.)

Do not put a 180 stat in it. Your ECM was designed for a 195 stat. A 180 will decrease fuel economy a bit because your ECM will (in theory) think the engine is too cool for best emissions and will be trying to warm it up, by making it run slightly rich.

[rdh2]

I just put a rebuilt engine in my '02. I hooked up my scan tool to monitor the temp, because I don't trust gauges. The half mark on my temp gauge is at 201 degrees. With a new thermostat and the cooling fan operation, the temperature varies from 195-215. 215 is about 3 needle widths above half.

['97ventureowner]

Both of the Ventures I owned did that, ( the needle on the temp gauge stayed at the half mark.) That was with the 195 thermostat installed ( never had any other temp range thermostat installed.) All of the other vans, Montana, and Silhouette, that I've seen over the years also read the same. You could also watch the needle move up from half if you were stuck in a line like at a drive thru. I'd either run the A/C or heater in cooler weather, and the needle would move back. When I first had concerns about this about 10 years ago, a couple of my friends who were GM techs said that was normal for these vans to do that and to just keep an eye on it so the needle doesn't go too far up. And to keep an eye on the coolant level, making sure it was maintained at the proper level.