Really Cold Engine...Thermostat?
Thread Starter
Advanced
Joined: Jun 2004
Posts: 83
Likes: 0
From: NC
Really Cold Engine...Thermostat?
I have a 1990 automatic coupe that does not want to heat up. When I drive about 15 miles with the A/C on at speeds around 35-45 mph it only heats up to around 150, in the summer it will sometimes get around 160-170. Back in July of this year I flushed, cleaned radiator and refilled my coolant system. Is there any way to know whether my thermostat is stuck open? Also what is involed in replacing it?
I also have an 1987 4+3 convertible that will heat up to around 180 degrees after driving about 5 miles at 35mph, this is why I think that it is odd that my 1990 runs so cool.
Thanks for the help!
Its beginning to get pretty chilly here and I don't like the thoughts of my engine running very cold, and I would enjoy some heat coming from the vents realtively quickly like in my 1987.
I also have an 1987 4+3 convertible that will heat up to around 180 degrees after driving about 5 miles at 35mph, this is why I think that it is odd that my 1990 runs so cool.
Thanks for the help!
Its beginning to get pretty chilly here and I don't like the thoughts of my engine running very cold, and I would enjoy some heat coming from the vents realtively quickly like in my 1987.
Race Director
Joined: Sep 2004
Posts: 13,793
Likes: 0
From: St. Peters MO Sometimes you have to prove yourself by doing alot of killing or alot of dying...
I have a 96 LT4 that I put a 160* stat in and I am running around those temps. On the TPI motors I believe that the stat housing is just under the throttle body. It's been a while since I've seen the TPI. It should be held in by two bolts. It is a simple fix... but a messy one too
You'll need to drain the coolant - loosen the hose clamp adn remove the inlet hose from the TB - disconnect the radiator hose from the housing - remove the two bolts and the housing - stat is inside - pull and replace.
Remeber to remove any and all traces of the old gasket and replace with a new one.
You'll need to drain the coolant - loosen the hose clamp adn remove the inlet hose from the TB - disconnect the radiator hose from the housing - remove the two bolts and the housing - stat is inside - pull and replace.
Remeber to remove any and all traces of the old gasket and replace with a new one.
Last edited by kwik_ta; Dec 19, 2004 at 04:01 AM.
Le Mans Master
Joined: Apr 2002
Posts: 5,726
Likes: 46
From: Waukesha WI
St. Jude Donor '15
How are you getting the temp? The 90 instruments are known to be inaccurate - I know mine are. Have you noticed poor heater performance or bad gas mileage. When my thermo stuck open my mileage went down a few MPG and my heater only blew outside temp (not fun in northern WI)
Replacing the thermo is pretty easy. The above directions are pretty close. If you have never done this before, you may want to get a Haynes or Helm book for the car to make sure everything goes smoothly.
Replacing the thermo is pretty easy. The above directions are pretty close. If you have never done this before, you may want to get a Haynes or Helm book for the car to make sure everything goes smoothly.
Thread Starter
Advanced
Joined: Jun 2004
Posts: 83
Likes: 0
From: NC
Dale you ask about poor gas mileage and heater performance, well the the heater does not get extremely warm, and I am getting around 13 mpg, although my 1987 convertible gets around 16 mpg. Maybe this information will help us determine if my thermostat needs to be replaced.
Thanks for all the help.
Thanks for all the help.
Race Director
Joined: Sep 2000
Posts: 17,298
Likes: 33
From: The Top of Utah
Originally Posted by 828790vetteman
Dale you ask about poor gas mileage and heater performance, well the the heater does not get extremely warm, and I am getting around 13 mpg, although my 1987 convertible gets around 16 mpg. Maybe this information will help us determine if my thermostat needs to be replaced.
Thanks for all the help.
Thanks for all the help.
RACE ON!!!
Safety Car
Joined: Sep 2000
Posts: 3,524
Likes: 4
From: Hinckley Ohio
Originally Posted by 828790vetteman
only heats up to around 150,.
even if it were a 160 stat you would get warmer than 150.......Plus it should NOT take 15 miles to reach operating temp.....so I don't think gauge is problem
Thread Starter
Advanced
Joined: Jun 2004
Posts: 83
Likes: 0
From: NC
For the stock L98 engine the thermostat is a 180 degree stat right? Can you guys suggest any particular brands that I should use to replace it?
Thanks for all of your help, greatly appreciated.
What fun get to start a car repair in 30 degree weather!
Thanks for all of your help, greatly appreciated.
What fun get to start a car repair in 30 degree weather!
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)
Joe Kucinski
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!
Michael S. Palmer
10 Revolutionary 'Corvette Firsts' Most People Don't Know
Joe Kucinski
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2
Michael S. Palmer
2027 Corvette vs The World: Every C8 vs Its Closest Competitor
Joe Kucinski
Melting Slicks
Joined: Jan 2002
Posts: 2,238
Likes: 4
From: Milan
Originally Posted by 828790vetteman
For the stock L98 engine the thermostat is a 180 degree stat right? Can you guys suggest any particular brands that I should use to replace it?
Thanks for all of your help, greatly appreciated.
What fun get to start a car repair in 30 degree weather!
Thanks for all of your help, greatly appreciated.
What fun get to start a car repair in 30 degree weather!
-Beppe-
Race Director
Joined: Sep 2000
Posts: 17,298
Likes: 33
From: The Top of Utah
Any good name brand of stat will work fine. Dole and Stant, first come to mind. Beware of the in store bargain, or no-name stats. The cheapies fail closed, causing a boil over, and possibly stranding you on the side of the road. The better stats fail open, like yours did, and don't create a disaster. A good stat should cost $5.00-$7.00. Don't pay over $10.00 or less the $5.00. Don't forget the gasket.
RACE ON!!!
RACE ON!!!
Burning Brakes
Joined: Nov 2003
Posts: 935
Likes: 2
From: Beverly, NJ
Originally Posted by CFI-EFI
Any good name brand of stat will work fine. Dole and Stant, first come to mind. Beware of the in store bargain, or no-name stats. The cheapies fail closed, causing a boil over, and possibly stranding you on the side of the road. The better stats fail open, like yours did, and don't create a disaster. A good stat should cost $5.00-$7.00. Don't pay over $10.00 or less the $5.00. Don't forget the gasket.
RACE ON!!!
RACE ON!!!
I also agree. I went with a 180 stat so my engine would run cooler, along with chip tune. I would not use the 160 stat unless you do alot of racing, and are concerned with squeezing more HP. I got one of the good ones too, where they fail open. Get that one. Good luck.
