intake manifold gasket help?

hi I have recently purchased a used 3.8L impala. drove the car with no problems for about 2 days, then 20 mins into driving the car on the third day, the car started misfiring and I heard this rattling/wierd noise sounded like from my engine, I only heard the noise when I pressed on the accelerator, took the car to a local mechanic shop, the mechanic looked at it and said both intake manifolds needed replacing, I did not ask how much because I knew it would be alot, I went and bought the gaskets, both upper and lower, and new spark plugs and wires, I dont have a garage so I have to work outside, so should I work on it myself?/ how difficult is it if you have done it? I am confused on what torques I need inches or foot, and also could this be the cause of the sound I heard?

would also like to add that I checked the oil not vanilla looking under cap, oil looked very chocolatly and was muddy and suddy looking soupy stuff, The coolant looked as though it had mud around cap, and brown stuff in it

The upper intake is the usual issue, as well as lower gaskets but they are less probable, no way for us to know your capabilities here. Google or do a site search for 3800 intake gaskets, plenty of info out there. BTW, do not drive the car in this condition.!

Weird rattling/ Misfireing sounds like a Clogged Catalytic to me...

Sound like this?
http://i232.photobucket.com/albums/ee46/MaImpala/2002%20Impala/th_100_4688.jpg (http://s232.photobucket.com/albums/ee46/MaImpala/2002%20Impala/?action=view&current=100_4688.flv)

yes hemi it does sound something like that, saw a video on youtube that had the sound clearer but cant seem to locate it at the moment

I found the video of the sound that sounds similar to the one my car is making here it is
http://www.youtube.com/watch?v=PiEXUtUPFRY

You may have a bad cat. I think you need to change the oil and flush and change the coolant to original Green. This will buy you some time with the intake gaskets. Also change you radiator cap to Stant 10230 or 11230. Dexcool is all right but it's not particular compatible with the silicone and nylon intake gaskets used and the cap on the radiator cooling system and all iron engine.

If you replace the gaskets with Felpro problem solvers and fix all leaks, then the Dexcool would probably work OK but you would need to make sure the radiator is compltely full at all times.

I've run dexcool with NO issues as long as you maintain your vehicle (like your kinda... Supposed to? :rofl:) but green stuff IS cheaper anyways, isn't it ? lol

other video has me wondering if its the Cat after all. when you rev up, does it die out (like in my video, couldn't go past 3900 RPM).

I found the video of the sound that sounds similar to the one my car is making here it is
http://www.youtube.com/watch?v=PiEXUtUPFRY

I could be wrong but that kind of sounded like the timing chain. It's really hard to tell from the video, but the knock sounded constant with increasing engine speed, whereas a rod or tappet knock would normally speed up with increased RPM. It could be other things, maybe even one of the drive belt pulleys or tensioner.

no car does not die at all, just makes this noise

Keep rumning with the oil/coolant mix and the world will hear your engine noise!

well guys I took everything apart step by step by the book, and put it all back together again with new gaskets upper and lower and I put coolant in and the coolant ran out of the lower intake manifold I am so frustrated I dont know what I did wrong

Sounds like maybe you didn't get one of the coolant elbows on good.

This thread was given to me by someone here. I hope it helps you solve the issue. I have not yet started mine so I can't really help. Best of luck.

The thread is step-by-step with pic's. It's all about the 3800.

http://www.pontiacbonnevilleclub.com...hp?f=53&t=3591 (http://www.pontiacbonnevilleclub.com/forum/viewtopic.php?f=53&t=3591)

well guys I took everything apart step by step by the book, and put it all back together again with new gaskets upper and lower and I put coolant in and the coolant ran out of the lower intake manifold I am so frustrated I dont know what I did wrong


Just wondering, when you took it apart, did you check the push/oil rods to see if any were bent?? Rolling them on a true flat surface like a pane of glass. If one wobbled it would need to be replaced. Hard to tell from a video, but I heard a knock, IMO an oil or piston rod knock. I could be dead wrong though. Honestly sounded like a piston rod, when the bearing gives out. Light noise until high RPM's then louder as the bearing try's to stall.

doing the upper intake gasket for my 05' 3.8 tomorrow, does anyone have any pics of the burnt/melted coolant passages near the TB? I'm told this is common when it leaks from this location and means the upper plenum needs to be replaced. I'd like to make sure I know what I'm looking for, or will it be fairly obvious? I also wonder about picking up one of the 60$ plenums from ebay anyone have feedback on them? I avoid ebay parts like the plague on my Z, but I need to get the DD going as quickly and cheeply as possible.

Also will I need to remove any of the accessory drives or is that assosiated with the lower plenum removal only?

TIA,
Casey

See, the threads that I posted in this thread:

http://www.automotiveforums.com/vbulletin/showthread.php?t=977062

These should explain the problem and the procedure to fix. One also has links to types of plenums and where to purchase.

As far as the ebay plenums are concerned are they stock OEM? If they are you may have the same problem down the road. If they are the new style with the redesigned stove pipe then they might be okay.

I found those links in other threads while I was researching here, but unfortunately they 'no longer exist'

Well, it appears that the entire "Techinfo" section of the site is gone. I'm betting on a forum glitch and that it will be back up and running again. May have to check back later.

As a matter of fact, none of the forum topic "exist" either. I'm definitely betting on a server glitch.

Sorry!

EDIT: It seems that the host server company had some sort of goof. It's being worked on and should be up again soon.

Links are back up!

Well I got it all apart, not a bad job, but I don't see any evidence of where it could have been leaking, so I'm a little nervous that this repair won't fix my problem. It was diagnosed as an upper intake vacuum leak by the dealership because it looked like there was some coolant in the area. It looks like there is a pretty clean border around the gasket area and I don't see any signs of coolant penetration. also, the entire inside of the intake is covered with oil and carbon, and I don't see anywhere that has penetrated the gasket either. I'm posting pics of everything to get a second opinion. Should I just install the gasket, re-assemble and hope for the best? or is there somethign else I should look into? I have a persistant 'bank 1 lean' code which is what set me down this path in the first place btw...

In the first and second pic you can see what looks like a puddle of coolant, but I see no evidence it came from the plenum, do you?

Also on re-assembly I will clean the surfaces, but should I put RTV on the new gasket or no?

http://www.fuergrissa.com/images/UIM/1.jpghttp://www.fuergrissa.net/images/UIM/1.jpg
http://www.fuergrissa.net/images/UIM/2.jpg
http://www.fuergrissa.net/images/UIM/3.jpg
http://www.fuergrissa.net/images/UIM/4.jpg
http://www.fuergrissa.net/images/UIM/5.jpg
http://www.fuergrissa.net/images/UIM/6.jpg
http://www.fuergrissa.net/images/UIM/7.jpg
http://www.fuergrissa.net/images/UIM/8.jpg
http://www.fuergrissa.net/images/UIM/9.jpg

http://www.fuergrissa.com/images/UIM/3.jpg
http://www.fuergrissa.com/images/UIM/4.jpg
http://www.fuergrissa.com/images/UIM/5.jpg
http://www.fuergrissa.com/images/UIM/6.jpg
http://www.fuergrissa.com/images/UIM/7.jpg
http://www.fuergrissa.com/images/UIM/8.jpg
http://www.fuergrissa.com/images/UIM/9.jpg

Now that I look at it agian there is oil all around my valve cover on the front bank (bank 1?) could a bad valve cover gasket be making me run lean on that bank?

*edit* also you can plainly see the oil pooling in the low spots of the inside of the LIM, should I be concerned about that?

Looks like the UIM has the reduced stove pipe and doesn't appear to have any signs of deterioration.

Are you going to take the LIM off also? This may be where your coolant leak is. Have you been running Dexcool? Has it been changed on a regular basis?

If it's the original LIM gasket chances are that some of the gasket material has deteriorated and is leaking coolant in to the cylinders.

what does the reduced stovepipe tell you? are you referring to the EGR tube?

well LIM gaskets came with my kit so I guess I may as well do it all and just hope one of these things fixes my lean condition. I just hate not having a smoking gun. not a big fan of pursuing possibilities untill the problem goes away. Wish I could have properly diagnosed the problem from the start, although at the time I thought I had (via the dealer).

well everyone here is the update, finally gave up and took the car to a professional mechanic that I trust. after he fixed it he said he does not believe that was ever the problem. and here it goes ready ...believes it was something down in the motor maybe a rod... he said you would have to tear the whole motor down and check for problems and it would be cheaper to just find a new motor and swap it. after paying for parts twice plus new plugs and wires plus labor I now need a new engine. After he fixed it the car still made the same, drove the same everything so the intake was never the problem, something in the motor maybe bent rod, so now i have to look for a new motor and pay to have it put in, not sure if its worth it:lol2:

what does the reduced stovepipe tell you? are you referring to the EGR tube?

well LIM gaskets came with my kit so I guess I may as well do it all and just hope one of these things fixes my lean condition. I just hate not having a smoking gun. not a big fan of pursuing possibilities untill the problem goes away. Wish I could have properly diagnosed the problem from the start, although at the time I thought I had (via the dealer).

Yes, the EGR tube that goes up into the Plenum.

The reduced stovepipe size was the fix used by some companies to reduce the deterioration of the plastic plenum around the stovepipe. The clearance of the original was much tighter and, with the high temp provided by that tube, the plastic would deteriorate into the coolant passages and cause leaking of coolant into the UIM.

As far as lean condition, my son in law and daughter's Mazda had a lean condition. It ended up being the MAF sensor being dirty. Make sure you clean that and the Throttle body well.