Thermostat.....

[knightrider2000]

Does any one have a number for a GM Thermostat, on a 99 Silverado 5.3??

 

I think mine is getting ready to go out..  it only runs 170-180

 

Matt G.

[CapnDean]

Matt:  You have hit a big one!  First off, if your truck is not overheating, your thermostat is not likely bad.  99% of the time they stick shut...not open.

 

I believe your truck comes with a 195 degree unit.

 

Basically there are 2 camps on this:

One says 195 is too hot and too close to boiling.  The other says the higher the temperature, the more efficient your engine is performing (obviously except overheating).

 

So:  Changing to a 180 thermostat, which is what us old schoolers were taught that an engine should run...180 degrees... Could possibly adversely affect your computer's instructions to your engine "hey, you're not running hot enough...lean out the mix"  etc....

 

Also:  I wouldn't bet my life on the accuracy of your factory gages either!

 

Just another 2 cents....boy am I full of yap today!

[chevy4x4trucks]

Quote from knightrider2000, posted on Oct. 31 2001,12:29

Does any one have a number for a GM Thermostat, on a 99 Silverado 5.3??

 

I think mine is getting ready to go out..  it only runs 170-180

 

Matt G.

 

Mine only runs in that range.

[knightrider2000]

Mine normally ran around 200-205..  Seems like it just taking it longer and longer to warm up than it did before.  I am kinda like what yall say, sometimes the cooler the better, but with that computer, it could screw everything up,  as usual  

 

Oh Well, if it gets to where it wont come up at all, i will replace it, otherwise i guess it is fine for now.  

 

Matt

[chevy4x4trucks]

If you're going to replace it might as well get an HPPIII and a 180 or 160 thermostat.

[CapnDean]

Matt:

 

 If your temp does not rise at all......it's not your thermostat!