Dex-Cool, in GM 3.8

[Drew99GT]

Originally Posted By: WishIhadatruck
I think for the 3.1 & 3.4 motors the Fel Pro problem solver gasket is the way to go but for the 3.8L motors GM makes a metal framed gasket that is problem the best way to go. They never offered a metal framed one for the 3.1/3.4 motors so Fel Pro is the best bet for those.



Hey Wish, do you know by chance if the first updated gasket set that GM put out for the 3800 was metal framed? Or did they go through a few design phases that led to the metal framed gaskets?

Our 99 Olds 88 had the gaskets and manifold replaced about 4 years ago.

 

[Drew99GT]

I don't even think there is a current 3.4L. There is the 3.5L and 3.9L VVT High Value motors and the 3.6L High feature DOHC motor.

The Lsx based motors are all leak free - Vettes, Gm trucks, GTOs, Impala SS, and the G8s.

 

[ls1mike]

The 3.4 is used in the Equinox and Torrent.
It features a roller cam, new intake manifold and gasket moving the location of the egr. Updated rods, bearings and pistions.
I belive it shares the water pump block and heads with the old one.
I have one sitting in my Garage.

 

[ls1mike]

Because I am bored...

New intake design

 

[Drew99GT]

I stand corrected Mike!

 

[ls1mike]

It has been good so far, 07 and we have put 60,000 miles on it.
(don't ask). All I have had to do is change oil.
No power steering pump (electric steering) While not as refined as similar motors of it's size. It has no timing belt to worry about and we average right around 23 to 24 mpg in mixed driving. With the redesigned intake and coolant system I should get a bunch more trouble free miles out of it.

 

[Drew99GT]

Unfortuentally I had Grand Am with the OLDER 3.4L and it was not a happy experience.

 

[WishIhadatruck]

Originally Posted By: Drew99GT
Originally Posted By: WishIhadatruck
I think for the 3.1 & 3.4 motors the Fel Pro problem solver gasket is the way to go but for the 3.8L motors GM makes a metal framed gasket that is problem the best way to go. They never offered a metal framed one for the 3.1/3.4 motors so Fel Pro is the best bet for those.



Hey Wish, do you know by chance if the first updated gasket set that GM put out for the 3800 was metal framed? Or did they go through a few design phases that led to the metal framed gaskets?

Our 99 Olds 88 had the gaskets and manifold replaced about 4 years ago.


I'm not sure when they started offering it. My '01 had a plastic framed gasket. My guess is not until at least '04 or '05? I don't really know however.


I considered trying for the lawsuit money but at best I'll get $50 due to the cars age. If I find the time I might give it a try.

 

[monte]

Some good info. So, I am thinking I should just change out the intake manifold w/ the one "wishihadatruck" posted. Has anyone used this one? If so, how long should it take and is it a feasible task for a novice? I figure for about $115 and a coolant flush I could have some peace of mind. I would also get a "stant spring rad cap" like the article "ls1mike" posted recommended.
Also, I ordered a UOA test kit. Would the results tell me if there is indeed a leak?

 

[Drew99GT]

Yup, a UOA will tell if it has a leak.

Changing the intake manifold and gaskets on these engines is not something I would do as a novice. If it was an old mopar small block V-8, it could done done in 10 minutes. But on the Series II 3800, you're totally disconnecting the fuel system, and I think you also might need to remove the push rods and rocker arms.

 

[Rock_Hudstone]

Originally Posted By: Drew99GT
Changing the intake manifold and gaskets on these engines is not something I would do as a novice. But on the Series II 3800, you're totally disconnecting the fuel system, and I think you also might need to remove the push rods and rocker arms.

Agreed, definetly not a job for beginner, you can get in over your head very quickly.

I just did the intake manifold gasket on a 3.1L GM engine, it was major job and I've been at this stuff for many years and have all the air tools and such. I was super careful and still had to remove the upper plenum twice because of fuel leaks on the injectors.

Even for my mechanic its a 5-6 hour job and they've done dozens of them.

I'd shop around for a trusted mechanic who has done the job successfully quite a few times, and don't let them talk you into using Dex-cool again.

 

[sciphi]

No pushrod or rocker arm removal needed.

First the fuel injection stuff gets taken off, then the upper manifold, then underneath it is the lower manifold. Unbolt that and remove carefully to get at the gaskets. Shop towels to stuff into the cylinder heads would not be a bad idea, since you can see the valves from there.

You can see the pushrods once you've removed the lower manifold. They do not need to come out, though.

And do not go with real Dex-Cool. Prestone long-life is similar but will not degrade the gaskets. You could even go to regular green as long as every last trace of Dex is out of the system.

 

[WishIhadatruck]

I believe sciphi is correct. 3.1/3.4 60 deg. motors require pushrod removal but the 3.8 does not. I considered doing it myself but decided against it. I've heard it is a minimum 6 hour job if you've never done it before but are experienced with engine work. I've done a bit of work on engines before but this would be more than what I've done in the past and so I was figureing 10 hours of work which I just didn't have time for. Luckily I had recently found a good mechanic and he's done lots of them. He seemed to think the new UIM was pretty nice and had no trouble with it and was impressed with all the extra pcs that came with it incase they were needed. I believe it even came with a couple of different EGR tubes to fit the different years to give you the reduced diameter even for the previous years. You should call them to check first however. My mechanic was unaware of the alum. framed GM gaskets but called and discovered they only cost a little more so that is what he used. His experience with the newest plastic framed ones is they still only last about 80k miles. He was glad to learn of the newer alum. ones.

Good luck.