Thread: Is the intake gasket a problem on 2004 & newer 3800?

05 came with aluminum gaskets so no worry.. He be uneducated lol just to be sure your car isn't an early 05/late 04, check around the end of the lim and heads to see if you see shiny gasket or black

Look under water neck on engine, you don't have to remove anything. This is the easiest spot to look at gasket The gasket is 1/4" thick and will be dull aluminum cooler or black plastic.

Might need a bright flashlight.

Also. If you still have dexcool (deathcool) in it you are going want to flush the coolant system, it is probable pretty slimy.

I flush with water a couple times over a week then fill with the green/yellow non dexcool.

Your neighbor is educated, seems like a nice person trying to help you out. May not be up to speed like a bunch of 3800 nerds that spend their days on forums. =0)

Take a look and see if your gasket is black or silver. Silver means you smile and be happy, black means should replace. As for Dex...I'm not a huge dex disliker. It will sludge up when exposed to air (at least the old versions did) and little stuff, but it doesn't cause the gaskets to break down and fail like many believed.

Originally Posted by BillBoost37

Your neighbor is educated, seems like a nice person trying to help you out. May not be up to speed like a bunch of 3800 nerds that spend their days on forums. =0)

Take a look and see if your gasket is black or silver. Silver means you smile and be happy, black means should replace. As for Dex...I'm not a huge dex disliker. It will sludge up when exposed to air (at least the old versions did) and little stuff, but it doesn't cause the gaskets to break down and fail like many believed.

Question: Is DEXCOOL more friendly to aluminum. I heard it is. The last motor I rebuilt - filled it with the DEX. Did I do a no-no?

Originally Posted by 99pgpgt

05 came with aluminum gaskets so no worry.. He be uneducated lol just to be sure your car isn't an early 05/late 04, check around the end of the lim and heads to see if you see shiny gasket or black

I found out while doing mine yesterday they didn't put the aluminum gaskets on until the 06 year.

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Originally Posted by Rico

Question: Is DEXCOOL more friendly to aluminum. I heard it is. The last motor I rebuilt - filled it with the DEX. Did I do a no-no?

Dex is fine with the aluminum gaskets, it eats away at the older gaskets. The fix for the dexcool problem as I said above was aluminum gaskets in 06

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Pretty much, every year of Grand Prixs were a Frankenstein car. Pretty much have to inspect everything yourself. Mine was an early '05 (Feb. '05) and had the black plastic LIM gaskets.

If yours is black, ~$50-$70 for you to fix it yourself. Pretty simple and straight forward job.

Originally Posted by afallucco

Dex is fine with the aluminum gaskets, it eats away at the older gaskets. The fix for the dexcool problem as I said above was aluminum gaskets in 06

This is the misconception. Dex doesn't eat the gaskets, the gaskets deform from heat etc and differences in metal from the aluminum LIM to the cast iron heads. The issue with dex is when it is exposed to air and turns back to oatmeal.

Originally Posted by afallucco

I found out while doing mine yesterday they didn't put the aluminum gaskets on until the 06 year.

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Anthony you have an 04 -_- smh

And yes...Dex was originally formulated to work better with the addition of a lot of aluminum in the cooling system. As well, it's been quietly reformulated a couple of times over the years. Last change was in about 2008-2009 from what I had heard.

And here's an article I had read at one point that helped explain the issues and takes it out of only being a GM gasket issue by mentioning how many Ford and Chrysler's were effected.

Closing The Gap on Intake Manifold Gaskets: Engine Builder

It does mention coolant neglect as part of the issue along with heat etc.

I have personally swapped out to different coolant with an hour long flush of clean water etc etc. Put plastic frammed back in (no others at the time) and used green coolant. 20K miles later pulled those gaskets to find them deforming and starting to degrade.

GM and others put metal sleeves into the plastic gaskets thinking they were being over torqued, and finally came down to redesigning them near the end of the production of these motors. The fix.. a better gasket.

Originally Posted by 99pgpgt

Anthony you have an 04 -_- smh

Doesn't mean I didn't look into it just because I have an 04.

I'd look into it even if I had an 08.

GM made changes, not necessarily by year. They made the changes more by when they ran out of a part in stock. The transmission is a perfect example. I've seen a 2003 car where the transmission didn't have the hardened 4th clutch hub. Why I'm not fully sure of.. it has production date of Nov 2002, but was a 2003 model. Which leaves the question out there.. is it 2003's built in 2003 that got the shaft or was it after GM ran out of the non-hardened ones? I'd bank on the latter.

Originally Posted by BillBoost37

This is the misconception. Dex doesn't eat the gaskets, the gaskets deform from heat etc and differences in metal from the aluminum LIM to the cast iron heads. The issue with dex is when it is exposed to air and turns back to oatmeal.

And thank you, I like learning new things everyday.

Hmm, turned out to be a good thread.