The '00 Grand Prix I just bought has a coolant in the upper intake, and it was Dex Cool tha was in the radiator. I'm going to get it fixed with the reinforced intake from ZZP; guess I'll save all my receipts and see if I can get a refund on it.

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2004 Impala SS - ZZP PCM, 3.4" Pulley, K&N CAI, TOG Headers, SLP Cat-Back, 180* thermo, Autolite 605s, PRJ Performance wires, Alternator rewire, GMPP Handling kit
2000 Grand Prix GT, Commuter Car - K&N CAI, GMPP Handling kit, ZZP downpipe w/U-bend delete, ZZP Plog, Alternator rewire

dexcool> plastic intakes....

toasty> useless information

GTP> GT

Turbo> SC

Summer> winter

oh....wait. that was too much huh?

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2001 GTP street car- GT45 turbo,Stage 4 Intense turbo cam,FMIC,150 wet, double roller timing chain, Diamond forged coated pistons 8:0:1, Diamond piston rings, cryoed L32 connecting rods, Cryoed crank, Clevite77 main bearings, Clevite77 cam bearings, Clevite77 L32 rod bearings, ARP Everything, Intense/meizere true billet Flexplate, Custom UIM, Intense oil pressure kit, Cometic 4 layer head gaskets, OE-R lifters, Cryoed L67 block, ATI turbo dampner, MUCH MORE, 6 more to choose from ASE Certified

does not GM put those seal tabs in the cooling system from the factory?

I also dont think its all the stuff people put in their cooling systems as, generally speaking, people are pretty neglectful of their cooling systems. Im sure adding something to fix a leak doesnt help, I agree with you there as there is virtually no way to know if there will be a chemistry conflict in the composition of the products, but I dont think its a leading cause.

Dex Cool itself may not be a 'bad' product so much as it is a bad combo. A high maintenance product (Despite its label) coupled with one system in a car that gets very little attention by most owners.

One of the major things seems to be Dex-Cools sensitivity to air. And then the mentioning of contaminants in a virtually closed system. I would like to know how, in a virtually closed system, I would be responsible for contaminants. Ive pulled radiator caps off extremely low mileage vehicles (we're talking less than a year old) and there had been dex sludge in quite abundance on them.

Im not picking Reptile, just kinda contesting what you are saying because I see things a bit differently. You certainly have an inside track on things. But the information I have read over the years certainly doesnt say that DexCool is a 'bad' product but it is far from being as good or equivalent to anything else out there.

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Scotty Hall
Bartlesville, OK
2001 Pontiac Grand Prix GTP
It whines a lot, but I like it.

The only limitation you will ever face in life is yourself!

I agree!

Interesting to me that I've not run into one GM mechnic that has flushed their Dex for green. I'm sure there are some but I've not met them yet.

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04 Indy SS build #972
XP, TOG's, Lightning injectors, 2.8 pulley, 105 CC springs, Wizaired, 3.29 gears, tripleedgeperformance ported blower, machined LIM, 180* tstat, RS12YC@.053, FP rewire, Alt rewire, stage 1 V boost, PRJ wires, Stage 2 IC

Well, here's the deal Scotty.....and I know that this article mentions fleet vehicles.

Fleet owned cars/trucks run a strict maintenance schedule, they check things regularly, change fluids at a certain interval etc. The bottom line is....if they don't take care of their stuff, they lose hundreds to thousands of dollars per day.

Joe Blow who buys a new car, and runs it without barely changing the oil every 10,000 miles and who never checks anything else just because the label on the bottle says that you can run something for 100,000 miles is ignorant at best. Just because Dex says just that, doesn't mean it will...just like the platinum/iridium plugs. You have to check your stuff. It basically boils down to just being an "extended life" coolant. It simply means that if you change your green at 30k miles, then you might go 50k miles on the extended life. It's not perfect, but in 10 years at this dealership, I have never seen Dex sludge on it's own.

They "used" to put a type of stop leak in as a preventative thing. If you talk to any old school engine builder he will tell you the same thing. You build an engine, and you "run in" an engine. Meaning that after you have a few warm up cycles...you re-check your gasket surfaces. When things warm up, things shrink. The benefit of the newer style gaskets that GM has put out in the last very few years is that the silicone seals tend to hold their normal size, pretty much eliminating having to go back over things like intake gaskets. I still do this after I put my intake gaskets and VC gaskets on...just for peace of mind.

It all still boils down to maintenance! I've personally had 4 Dex filled vehicles since 98....put well over 100k miles on all of them except for my GTP. I have never had any issue with anything other than not changing my plugs in a Grand am I had...I did that at 70 k miles, and they were pretty much toast.

Question me if you will, but you can't argue with experience....and I'm sure there are plenty of people who can speak from their own experience.

OK, I'm done with my run on's.

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GreenBastardPerformance2000 GTP Coupe (the green bastard)
XP, Pacesetters, LS1 TB & MAF,MSD System, P&P LIM, P&P GenV w/ 3.2, 3.0, 2.8, Devil'sOwn Injected 100% Methanol,PowerTuned, TripleEdge Trans w/3.29's
12.92 @ 105mph

I see your point completely. However, if I have to change the coolant at 50k to keep in good shape, then why label it as a 100k coolant. I agree with you on the point of 100k plugs too. Ive done maintenance on more cars than I care to count and I cant begin to tell you how many platinum plugs I have pulled that were in horrible shape long before the 100k. So I do understand what you are saying.

With regards to experience, my wifes GA had the sludge on the radiator cap and that is despite having it flushed on a regular basis, probably every other year or so. She never drove that much her maintenance schedule was more time based than mileage based. My GP had the same issue and we all the know the story with it. I have serviced customer vehicles, many, not all, but many have had the same sludge build up on the radiator cap. But I have yet to see one green, yellow or red coolant based vehicle with this issue.

So I wont argue experience but ours have been basically polar opposites.

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Scotty Hall
Bartlesville, OK
2001 Pontiac Grand Prix GTP
It whines a lot, but I like it.

The only limitation you will ever face in life is yourself!

I've gotta say that I haven't seen the green stuff sludge up as well...BUT I have seen severe corrosion because of the protective properties breaking down.

Now that I typed that....for some reason I kind of remember reading up that Dex-Cool was a "self destructing" type of coolant. Giving signs of breaking down before other engine damage can occur. I'll have to see if I can dig up something on this.

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GreenBastardPerformance2000 GTP Coupe (the green bastard)
XP, Pacesetters, LS1 TB & MAF,MSD System, P&P LIM, P&P GenV w/ 3.2, 3.0, 2.8, Devil'sOwn Injected 100% Methanol,PowerTuned, TripleEdge Trans w/3.29's
12.92 @ 105mph

There are two major classes of coolant that I am aware of. OAT (Organic Acid Technology) and HOAT (Hybrid Organic Acid Technology). I believe, dont quote me, DexCool is a HOAT, and I have often wondered if it was possibly the formulation that makes it a HOAT that is the issue. As far as I know the green ethelyne glycol is a OAT coolant.

That said, I do not know what the yellow (Ford) and Red (Toyota and others) coolants are. They may well be HOAT's but Im pretty sure they are formulated differently and what level of silicates they have I dont know either. I also have not had much chance to look into the G-05 coolants either.

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Scotty Hall
Bartlesville, OK
2001 Pontiac Grand Prix GTP
It whines a lot, but I like it.

The only limitation you will ever face in life is yourself!

I stand corrected, I went and looked at my info again and DexCool is a OAT coolant. What DexCool does differently from other OAT coolants is that it does not contain coolants and I believe reduced potassium if not completely eliminated.

I know prior to switching out the Dex Cool in the GP, my oil analysis showed virtually no potassium (high sodium coupled with potassium usually indicates a coolant leak) though I knew for fact I had a coolant leak from the LIM. As soon as I switched from Dex Cool to a green coolant my potassium skyrocketed in the oil analysis giving the final confirmation that there was a coolant leak.

So if I were a gambling person, I would say there is something in the formulation of DexCool that causes that sludge and the reason its not seen in all vehicles I would bet could be traced to metals used in the coolant system and engine, i.e. iron block and heads vs. aluminum. Just a thought.

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Scotty Hall
Bartlesville, OK
2001 Pontiac Grand Prix GTP
It whines a lot, but I like it.

The only limitation you will ever face in life is yourself!

I went down a long line of used Fleet vehicles mostly Impalas and a coupe of GP with varying mileage and looked at their cooling systems (overflow bottles and radiator caps). All of them had sealing tab "sludge", but none had that redish rusty looking stuff the guy with the 96 blazer (originator of the Dex Internet postings IIRC) posted about seeing.

I'll look at my sons 99 GTP this afternoon to see what his radiator cap looks like. I know his car has had nothing but Dex, since we bought the car from the original owner and I saw his maintenance records.

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04 Indy SS build #972
XP, TOG's, Lightning injectors, 2.8 pulley, 105 CC springs, Wizaired, 3.29 gears, tripleedgeperformance ported blower, machined LIM, 180* tstat, RS12YC@.053, FP rewire, Alt rewire, stage 1 V boost, PRJ wires, Stage 2 IC