Another GM Intake Manifold Gasket

[Redneck53]

Good Day Guys,

I have a 95 LeSabre (3.8)which recently had the leaky intake done. This engine has never seen Dex. The problem is more than likely the low-ender material they used in the factory gasket. Wow, what a nerve, using this sh*&&y material for 27 yrs

and we let them get away with it.

Cheers

Bry

 

[ekpolk]

During my Buick ownership odyssey (98 Regal GS), I was at the dealership (a sadly frequent occurrence...) and actually had a tech flippantly refer to the infamous orange stuff as "RustCool". I almost started leaking myself (if you know what I mean) I was laughing so hard. Myself, I like to think of it as Agent Orange for Engines.

 

[beanoil]

ek,
I don't know if Dex had a specific role either. Seems like quite a coincidence that more gasket issues came after Dex's intro. I think that GM had a lot riding on Dex, as one of the first long life fills for auto's, and wouldn't have changed from it if it poured out on the assembly line. Obviously, Ford "had a better idea", as they only used Dex in a couple of cars, for a very short time before adopting their own version of G05. It would be very interesting to have feedback from an early V6 owner on green, and someone who switched from Dex to another fill, to see if there is a relationship.

 

[lght1]

Hi

I dont think dexcool is the issue but rather plastic framed gaskets.

OAT coolant suffers from other issues such as any trapped air in the system.
Unlike silicated coolant, OAT requires that it always be in contact to prevent corrosion..or rust forms.

Silicated plates the surfaces and thus, there is always a level of protection available.

The metal framed gaskets for all the all the LIM gaskets for bothte 660 family and the 3800 SII should solve thee problems.

I suspect (hope) GM has used the aluminum framed gaskets for their new 660 versions staring with the 3500 Malibu.

 

[tmorris1]

quote:

---

Originally posted by beanoil:
ek,
I don't know if Dex had a specific role either. Seems like quite a coincidence that more gasket issues came after Dex's intro. I think that GM had a lot riding on Dex, as one of the first long life fills for auto's, and wouldn't have changed from it if it poured out on the assembly line. Obviously, Ford "had a better idea", as they only used Dex in a couple of cars, for a very short time before adopting their own version of G05. It would be very interesting to have feedback from an early V6 owner on green, and someone who switched from Dex to another fill, to see if there is a relationship.

---

I think it is somewhat coincidence. These engines were introduced about the same time that they started using Dexcool so it is hard to say that Dexcool is the problem.

 

[ekpolk]

tmorris:

Respectfully, the 60 degree family (2.8L, 3.1L, 3.4L, and now 3.5 and 3.9L) goes all the way back to the late 1970s. Dexcool is a much newer product. As a point of interest, the 231cid/3.8L/3800 90 degree V-6 started production way back in the early 1960s and has development roots into the 50s. It is interesting that there does not seem to be a reputation for bad gaskets in the early days before Agent Orange (dex). That does not, of course, mean that the coolant is the cause. Who knows. . .

 

[brianl703]

I am running a Dexcool clone (the Peak stuff) in my 1988 Mustang GT which has the 302 engine.

I will certainly report on the cooling fluids forum here if the intake manifold gasket develops a problem!

 

[lght1]

Hi

Plastic framed gaskets.

2-EHA found in OAT coolants has been said to be a "plasticizer".

Whether or not this is true is unknown to me, but the plastic framed gaskets have always shown the same sort of failure.

The silicon impregnated sealer is pulled away from frame yielding a pressure leak.

The fix is the Fel Pro Problem Solver. With this properly installed...I now wouldnt hesitate to buy a 660 engine

 

[ekpolk]

lght:

So basically what you're saying is that the Dexcool attacks gaskets of the older design, which apparently had worked just fine before the change from lime juice to Agent Orange?

Would the safe strategy for a car that has not yet begun to bleed be just to switch to green coolant?

 

[Frank D]

I had a 1990 Corsica with the 3.1 V6 and green antifreeze. I bought the car new and kept it until it was totalled in an accident in 1996. It had 95,000 miles on it and never had any antifreeze leaks.

 

[cousincletus]

^^^ I've heard the same thing. I switched the orange to the green in my 2002 Cavalier because of the possible issues with dexcool. The problem seems to be that the orange stuff doesn't last as long as advertised. So I figure if I have to change more frequently may as well use the cheaper green stuff.

 

[Dark Jedi]

well I dont know if the dex coolant is the cause of the gasket failure. maybe a coinencadence(I know I cant spell lol) I know I saw my gasket and it had a long tear in the side of it. so cant see how the coolaint can cause a gasket to tear. but again I am not a master mechanic for that matter lol. maybe the gaskets cant take the pressure the engine produces? but again the car is hardly WOT. I accually baby that car lol. now my V-8 Dakota I do WOT alot. must be the sound of the V-8 lol.

 

[lght1]

Hi

EK-

I just dont like plastic framed gaskets, silicated coolant or not.

With the Series II 3800 ( first to get Dex), one can expect the LIM gasket to fail about 70-120k range. Some had already switched to another coolant (OAT or not? - unknown) and still failure.

I did the Upper and loweres last year on my car using the felpro gasket. It was much more robust than the OEM blue silicon design.

There have been several attempts to "cheap" fix it. At first, over torquing the gaskets was suspected to be causing the issues and they added steel rings to the bolt holes on gasket.

This fix lasted about a year or so, and now the aluminum is now offered across the board for many engines.

I have seen the FelPro Problem Solvers...and this gasket alone would now make it possible for me to purchase a car with the 660 in it.

 

[Mud]

lght1 is right on the money.

Dex-cool does not play well with air in the system. It does not attack any gaskets.

Inferior gasket AND crush design (too-small, to few fasteners, loosening over time) = seepage when engine warms.
Seepage allows air back into system as engine cools.
Dex-cool reacts with the air in the system - sludge and more problems as the cycle continues.

Dex-cool of itself is OK, but the green stuff is much more tolerant of any air in the system.