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What coolant color should a 1999 Grand prix GTP have?

Tomtopdog12

New member
Hey guys

I check my engine bay quite a lot, i've been meaning to flush the coolant out of my car (not because it's bad but because i want to :p) and mines green. I heard you're suppose to use orange? I've been using green Prestone for years and years and the car runs super well. The Temp gauge doesn't go over 100C ever. it sticks around 80c in the summer and in the middle of that in the winter.


What do you guys think?

Thanks!
 


Run the green. As long as you change it at regular intervals and refill using distilled water you should have no issues. I switch both my GP and Bonneville to green years ago and have yet to have a problem related to the coolant type.
 
I was super worried, I've ran that in my car since we got it 4 year ago (starting modding a year ago) and i was thinking i was hurting it. what's the regular temp for these cars as dailies? every time i'm out i'm peering down at the temp gauge hoping it doesn't get to high. Though I've never had a heat problem. (trans cooler next?)
 
Factory is dexcool, which is orange.

Many switch to green, it makes no difference.

195-200º is the avg coolant themp they will run at with stock thermostat on the open road. Factory gauge cluster does not truely tell you the coolant temp, it's not something that is very spot on. The first big line past 160 is around 190ish.
 
I've heard to stay away from dexcool.....not even the guys at my work like that stuff. And okay, I was thinking of putting in a fan switch so i can turn the fans on when ever i want. But i think a new PCM tune will already do that for me.
 
Any of the dexcool stuff made after like 2009-2010ish or so (they switch how it was made) is just fine to use. Both my old 2010 and current 2012 silverado run factory dexcool and it has no issues. Just over 100k on my 2012 with the factory stuff and it's still bright orange, no sludge/brown stuff.
 


I wouldn't bother with a fan switch, just let the PCM do it's thing. These engines are designed to run hot from the factory, IIRC the high speed fan comes on around 228F or so.
 
I wouldn't bother with a fan switch, just let the PCM do it's thing.
Very much agreed. I had aux fan switch from uhh ..pfyc, I think.

I didn't feel it benefited much unless it was over 100 ambient in stop n go. Even then I thought it might be kinda hard on the charging system, so barely used it.
 
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