I've always been a Gm fan, even though the pops retired from Fomoco. But this is the final straw. I now know that 99% of the gen II 3.8l intake manifolds will fail before 100000 miles whether you maintain your vehicle or not, and regardless of the type coolant you use. Talk about fleecing, I'm so f#%&ing angry I'm not sure I'll ever purchase another American made vehicle again. I'm not a rocket scientist by any means but I would have had reservations if one told me they were going to run 1000+ degree air through a plastic part. I love my Bonne' but she'* leaving my life after I replace the intake, the tears will dry, and I'll drive again but it will be with a more responsible manufacturer.

Perhaps, before you go out and buy another plastic plenum you might get the part # for the Series III aluminum plenum and the Series III plenum -> Series II TB adapter so that it will never happen again.
Once you get the part # for the Series III upper intake plenum go to www.gmpartsdirect.com and order the aluminum plenum for $106 -to your door. The TB adapter plate is gonna be about the same price, but you can't go wrong for $200 -heck the Dealer is gonna get you for $200 for just the plastic plenum alone.

Better luck -oh, and I'm still going strong at 174,000 miles on my original plenum -my friends old 1995 SLE just had the upper intake plenum bite the dust at 234,000 miles, and I am aware of more than just these two Series II'* that are still using the original upper intake. My sisters 1997 GP GT has 152,000 miles on the original, my cousins 1997 GP GT has 137,000 miles -still the original intake, my brother'* 1998 GP SE 159,000 miles original upper intake mani, same brother'* 1998 Olds LSS still on the original upper intake plenum at 162,000 miles.
Key to these survivors -180* t-stat drilled with either 2x 1/16" or 4x 1/16" holes. Not complete protection, but buys a few miles.

Tim, I understand why you resent the fact that you KNOW the original intake design is faulty, but the answer is not to buy a different car! Once you buy something else you'll have a whole different set of issues to deal with. I PROMISE you will be hard-pressed to find another setup with the reliability, power, and responsiveness of the 3800. There are at least two viable solutions to the upper intake problem. The first, as already suggested, is to get an aluminum upper intake and throttle body adapter. The second is to modify your EGR stovepipe in order to redirect the hot gases away from the composite. The composite upper intakes will hold up without any problem if the EGR setup is changed.

I would strongly suggest that you let your anger subside a little before deciding to wave goodbye to the Bonneville. Like OLBlueEyes said, if you can throw $200 at your car and have a reliable machine that will take you to 200,000 miles or more, you've got one of the better cars of the last two decades.

Sorry guys but I'm with Tim on this one. I've just had my second intake manifold go in 52,000 miles as detailed in this thread:

http://www.bonnevilleclub.com/forum/...ic.php?t=27138

I too have always been a diehard GM fan but this is just a scam. I will never buy GM again. And as for your remedies you offer, for those of us with little or no mechanical experience our only recousre is to take it back to the dealer and have it fixed. And as your home-made remedies are not officially recognized GM alternatives, they won't do 'em. All Mr. Goodwrench can do is patch it up until it blows again.

I suppose I could throw the dice and try to explain these possible solutions to another mechanic and hope they understand and can fix. But it'* just really not worth my time. When I pay this kind of money for the top-of-the-line that Pontiac has to offer I shouldn't have to waste my time and money finding better design solutions to problems they built. And this is no small problem. This affects millions of automobiles manufactured over many years. They had ample time to fix or even acknowledge the problem. They chose not to even after redesigning the parts. This is not the definition of a responsible manufacturer. I'm not giving up on all American made cars, but I'm not giving GM another chance.

They acknowledged the problem, and have fixed it on the newer models. But its not a safety hazard so its not like their gonna recall it. Obviously plastic is gonna flex. Big deal. If you honestly think your gonna find another car that can go 200k miles with the only problem being a bad intake gasket, I think you're wrong, but I'd like to see you try.

I'm die hard GM and we have 7 GM cars right now. The GTP has NEVER been in the shop...imagine that a 400hp FWD car thats never in the shop. Nothing has broken. The SSEi has been in the shop once, and thats for a lower intake manifold gasket, wow 125k on the car and we've had to fix one thing on it. (oh yeah, the rear window cables or whatever broke, but that was an easy fix) The '90 GP coupe was in the shop once to get an oil leak fixed. (it wasn't even a big leak) My STE has been in the shop only for transmission work due to the modifications i have done to it, that has nothing to do with the manufacturer. And neither my sisters '93 GP LE, nor my other sisters '93 Olds 88 have ever been in the shop since we have owned them. My winter beater is a POS $200 car, but even with 185k and big rust holes it still starts every time i turn the key and everything works on it, not only that but it runs excellent and gets really good gas mileage. May I add that all of our cars besides the GTP (28k) and my STE (80k) have over 100k on them. Actually they are all at right around 130k besides my beater.

And then there is my neighbors Audi A4 1.8T which is in the shop at least twice a month, usually for more than one day each time.

If you honestly think a bad intake gasket is a reason to get rid of a car, then maybe you should start walking o riding your bike or something, because car ownership is a little more complicated then that for most.

Shawn

Still running strong at 138,000 in the LTZ. Had no issues int the old LTZ as well. Although I see that there is an issue with the Plastic one, with the Aluminum one available, I don't see why giving up on GM should be an issue. yes the design was faulty, but it is fixed and it doesn't speak for all GM models. Give them another Chance.

200k? I'd be happy with half that. But after having to replace it twice in 50k I doubt this car will ever see anything close to that.

You can't beat the reliability of a Jap car but there is some kind of magic with the
GM Bonnevilles. I get in and drive and I love it. The comfort, performance, safety, and feel.
OH by the way don't forget most foreign jobs have rubber timing belts that have to be changed @ 60k ($300-400) after they soak you. Aluminum heads that blow gaskets
etc etc.
I think an intake gasket on the 3800 is a minor fix. Like changing a water pump.
Its right on top and easy to do.

If you've replaced two in 50k, either someone isn't doing something right, or something is warped, and the gaskets are gonna keep going until thats fixed. Personally I would recommend changing the gasket by yourself since the part itself is only like $20, but if you want to pay over ten times more because you don't know how to and don't want to learn (since there is at least one descriptive write-up on here of how to do it), then go ahead, I can somewhat understand that. Besides, if the car only has 50k on it then I would bet at least one of those gaskets was fixed under warranty and didn't cost you anything. But lets say that 2 of them do go every 50k, its still not gonna cost much in maintenance to drive the car. I mean a battery every 5-8 years, and an alternator or two and you're at 200k. Other than that what goes wrong? You buy something foreign and chances are you're gonna have to replace a timing belt every 40-60k miles, as was already said earlier, and thats gonna run you close to $500 each time. So its gonna cost you at least as much just to maintain that engine as it will cost to fix this one a bunch of times. And yeah, you could probably hold off on the timing belt until 80 or 100k, but sometimes not, you never know when they're gonna go, and if it does go, its gonna cost you a LOT more than just a belt costs.

I understand what you're saying here, but I'm telling you all cars have their problems and you're really not gonna do better going with a different brand.

Shawn

Thats true - all cars are going to cost you one way or the other.
Just try tapping the bumper on some of these new models and see
the damage you get.
You'd be lucky if the thing doesn't fall off on the road, styrafoam and all.