Hi,
I have a 96 coupe w/ the 2.2 and 3 spd auto. 71k original miles and runs great. This is my first cold season w/the car (I live in Chicago) When driving in the city or even going 50-60 mph the gauge is right in the middle, heat works fine. When on the tollway going to work doing 65-70 mph, temp gauge goes way down, below the normal area.. Car had flush and fill 3 years ago w/Dexcool ( the orange stuff) installed and new T-stat. Is this considered normal? If not, any ideas why it does this?
Thanks!
if it wasn't a gm thermo, could be that the spring isn't sufficiently strong enough to keep closed at highway speeds. also, you're due for another flush and fill.
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yeah prob thermometer stuck
another idea is that your going faster= more air flow =cooler temp just a thought
mikieb510 wrote:another idea is that your going faster= more air flow =cooler temp just a thought
yeah, but there's no reason for the temp gauge to drop and to lose heat if your thermostat is working.
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mine always stays right in the middle, i would say the thermostat is not closing all the way.
I have the same problem with my S-truck, only in reverse. In the summer heat, it reads a normal temp cruising the highway but once I get onto the surface streets in stop-&-go, well...
A check showed me it was the fan-clutch to blame, but then I also have the same max operating temp problem as you. I've had a Robertshaw & a Rad-Cool thermo in it since I got it back from the engine rebuilder, and it still don't hold at 195* like it did before. Having read this thread, I'm wondering if maybe it is beacause I don't have a GM 'stat in there. I'll try & see...
Thanks Rich!
Go beyond the "bolt-on".
Nickelin Dimer wrote:I have the same problem with my S-truck, only in reverse. In the summer heat, it reads a normal temp cruising the highway but once I get onto the surface streets in stop-&-go, well...
A check showed me it was the fan-clutch to blame, but then I also have the same max operating temp problem as you. I've had a Robertshaw & a Rad-Cool thermo in it since I got it back from the engine rebuilder, and it still don't hold at 195* like it did before. Having read this thread, I'm wondering if maybe it is beacause I don't have a GM 'stat in there. I'll try & see...
Thanks Rich!
Im guessing with you though...your temps are going up dramatically...whereas his are going way down.
I had this happen in a car of mine. It had a Failsafe thermostat in it which stuck open, so in city driving I was fine, but once I hit the insterstate...you could see that needle drop. I am pretty much 100% sure that is your problem.
Thanks for all the answers! Is the stat difficult to get to? I'd like to do this myself, any things to watch out for? I get the impression the OEM stats are best, are the ones from the discount stores crap?
Thanks again!
Most stuff from the discount stores is.
"You get what you pay for"
Remember that.
If you can locate the housing, you can replace it.
Go beyond the "bolt-on".
Its in the upper rad hose, remove the 3 10mm nuts holding the aluminum housing on the engine, pop the thermostat out, remember which way was pointing in( spring towards the engine) replace the gasket and reinstall the thermostat, be careful that the thermostat doesnt drop down out of its place while installing it or you will crack the housing when you tighten it back up. Be sure to bleed out the air when filling the coolant, there should be a bleeder on the thermostat housing to bleed out the air.
As far as brands, Stant is a safe bet, or you could get a thermostat from a dealer but It may be a Stant brand anyway. when you go to the parts store ask what the most expensive thermostat is and buy it. If its more than 15 bucks they are trying to hose you. Here is a good example
http://shop.advanceautoparts.com/ProductList.aspx?parttype=133&ptset=A&searchfor=Thermostat+-+OE+Replacement
get either the 10.99 or the 11.99 instead of the 6.99 one. Sure they are the same brand but you gotta think in your head that there has to be a difference in quality if you can get a same brand thermostat at half the cost in the same store! Now if you dont see that, i dont know what to say.
01 cav w/01 3400 gam gt 4t45e
I did the flush and stat change today and have a few observations. I ended up buying a Stant "superstat", the store didn't have the premium one. The old stat had a very cheesy spring, the new one had a much thicker and stronger one. I would say the old stat spring was the same size as #14 wire. The new stat spring is like #10 wire, I should have taken pics but wanted to get finished. I haven't had it on the X-way yet as I'm on vacation but I think this will do the trick.
I want to thank everyone who took the time to reply and wish everyone a safe and happy holiday.
It's fixed, WooHoo!
I had a lengthy X-way drive today and the gauge stayed right in the middle. Car is toasty warm inside.
Thanks again, you guys are great!
good to hear, stop back if you run into any other problems.
01 cav w/01 3400 gam gt 4t45e
