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

M

mntnbiker

New member
My neighbor told me my wife's 2005 GP 3.8L (naturally aspirated) will most likely need an intake gasket at some point since the factory intake gaskets are kinda junky. He said anywhere from 80k miles on up they start having issues. My wife's has 132k. Is what my neighbor saying have any truth to it?
 


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.
 
Thanks for the tips everyone! I will do some investigating tonight after work and hopefully see "silver" and not "black". As for the dexcool, I just had my mechanic friend put new hoses and a flush and fill and he suggested sticking with the Dexcool approved coolant. He said it is not the same formula as when it first came out and he has heard the stories/rumors of the original stuff eating gaskets and not eating gaskets.
 


BillBoost37 said:
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.
Click to expand...

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?
 
99pgpgt said:
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
Click to expand...

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

Sent from my ADR6400L using Tapatalk 2
 
Rico said:
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?
Click to expand...

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

Sent from my ADR6400L using Tapatalk 2
 
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.
 
afallucco said:
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
Click to expand...

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 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.
 
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.
 


BillBoost37 said:
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.
Click to expand...

And thank you, I like learning new things everyday.
 
[QUOTE is it 2003's built in 2003 that got the shaft or was it after GM ran out of the non-hardened ones?][/QUOTE]

I think most 97 to early 03 buyers got the shaft on that one, lol... Stupid bean counters.
 
So my wife has the black plastic gasket set on her 05 :( What should I be watching for if this gasket starts to fail? She has about 132k on the GP right now.
 
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