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1995 Pontiac Grand Prix GTP Engine Coolant / Antifreeze

I bought this car on 9/3/2003 and am very impressed with it. Really I am not complaining. It is a great car. I love the 210 hp 3.4 L DOHC engine.

I checked the engine coolant and saw that it was BROWN! I decided to get a Prestone Back Flush Kit and back flushed the entire cooling system for 30 minutes. I then put in a bottle of Prestone Super Radiator Cleaner and ran it with just water for 5 hours of on and off driving. I then back flushed the entire system again for 30 minutes, took out the overflow tank and cleaned it, and replaced the thermostat.

I didn't know what antifreeze to use so I put in about 2 jugs of Prestone Extended Life 5/150 Antifreeze (Red DEX-COOL). I was smart enough to look through the whole owners manual for the car and it didn't say anything about DEX-COOL, but it didn't say anything about just plain green coolant either. All it said was to use a coolant that met GM Specification 1825-M. Both Prestone green and red meet this specification.

My question is which coolant did my car come with? If it did come with green, should I go back to green after putting in the red? I am gonna try calling a few parts departments at Pontiac dealerships to find out. If it is green, it won't bug me much to back flush the system again for 30 minutes, run Prestone Super Radiator Cleaner through it again for 5 hours, back flush again for 30 minutes, replace thermostat, clean out overflow tank, and fill up with Prestone green.

Thanks In Advance, BTJustice

Reply to
Buford T. Justice
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Called a local Pontiac dealership and talked to both parts and service. They said it was red. The car was made in 12/1994.

BTJustice

Reply to
Buford T. Justice

If it says nothing about DEX-COOL in the manual or on the coolant reservoir, it came with regular green coolant. Many models did not start using DEX-COOL until '96.

Reply to
Robert Hancock

Wonder if I should flush again and go back to green then.

BTJustice

Reply to
Buford T. Justice

I found an old GM bulletin on this subject:

"DEX-COOL(TM) MAY BE USED IN GENERAL MOTORS VEHICLES ORIGINALLY BUILT WITH CONVENTIONAL (GREEN) COOLANT WITH THE FOLLOWING CONSIDERATIONS:

  • VEHICLES ELIGIBLE FOR BACKSERVICE ARE 1994 AND 1995 MODELS (EXCLUDING 1994 J BODY WITH 4 CYLINDER ENGINES).

  • THE SERVICE INTERVAL FOR DEX-COOL(TM) INTRODUCED INTO AN OLDER MODEL VEHICLE ORIGINALLY BUILT WITH "GREEN" COOLANT WILL BE 2 YEARS/30,000 MILES (50 KM) (NOT 5 YEARS/100,000 MILES (160,000 KM)).

  • ALL THE "GREEN" COOLANT MUST BE REMOVED FROM THE COOLING SYSTEM BY MEANS OF A SYSTEM FLUSH. THIS MAY BE ACCOMPLISHED WITH A WATER FLUSHING DEVICE OR A GMDE WATERLESS COOLANT CHANGER (USE A UNIT DEDICATED TO "GREEN" COOLANT, NOT DEX-COOL(TM)).

IMPORTANT: WHEN USING A GMDE WATERLESS COOLANT CHANGER, CONDUCT THE PROCEDURE TWICE, ONCE WITH WATER, AND ONCE WITH DEX-COOL(TM).

BACKSERVICE WITH DEX-COOL(TM) IS ADVOCATED BECAUSE OF ENHANCED WATER PUMP SEAL DURABILITY EXPERIENCED WITH THIS COOLANT."

Reply to
Robert Hancock

Please look under each paragraph for replies...

OK. So the red coolant will work with my 1995 Pontiac Grand Prix GTP with the 3.4 L DOHC engine. However, I will not have the 5/100 length but the

2/30 length instead. Why is that exactly?

Backservice is advocated? Meaning that by using red instead of green my water pump will last longer? Will red affect the seals in the engine?

Sincerely, BTJustice

Reply to
Buford T. Justice

I called another Pontiac dealer today and talked to their service department. They said it was green originally since the car doesn't say DEX-COOL on the radiator cap and there is no DEX-COOL sticker. The owner's manual also never mentions DEX-COOL. Not only all of that, but by switching to red, I will run the risk of damaging / ruining hoses, seals, and gaskets.

So, right this instant, my car is sitting outside back flushing all the red DEX-COOL out. I am gonna run a bottle of Zerex Super Cleaner though it for about 5 hours driving time, reflush, and fill up with Zerex Green 5/100.

DEX-COOL is great if that is what your car came with, but mine didn't so it is green for me which is also great. It is nice that Zerex (Valvoline) has a green coolant that will last 5 years / 100,000 miles.

BTJustice

Reply to
Buford T. Justice

I'm not exactly sure why they don't advise any longer service interval - it may be because the extended-life coolant additives don't work as well as they could if there's any residue of green-type additives in the system.

One of the advantages of silicate-free coolants like Dex-Cool is indeed supposed to be extended water pump seal life.

Reply to
Robert Hancock

What are you using in the 1995 Sunfire on your webpage?

BTJustice

Reply to
Buford T. Justice

I don't have that car anymore, actually (suppose I should take that picture off there..) but when I changed the coolant when I had it, I just used the green stuff. Didn't have the equipment to totally flush out the old coolant, anyway..

Reply to
Robert Hancock

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