In regard to the notorious 3.1L v6 by GM and it's upper and lower intake manifold gaskets... Do seal additives even come into contact with these seals from within the engine? Or is it that they do, but on the oposite side of where the antifreeze is? Basically, you have the seal holding back antifreeze on one side and oil on the other; therefore, seal conditioners do nothing to prevent this from eventually going bad?
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? about seal conditioners and intake gaskets
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Intake gaskets should not come in contact with oil.
Originally Posted By: Johnny
Intake gaskets should not come in contact with oil.
That said, help me understand because I don't understand the design from within. If oil does not come into contact with intake gaskets, then how is it that antifreeze leaks into the oil when the go bad? To me, it sounds as if there is oil on the other side of the seal. I'm just trying to understand how it is that this occurrs?
Intake gaskets should not come in contact with oil.
That said, help me understand because I don't understand the design from within. If oil does not come into contact with intake gaskets, then how is it that antifreeze leaks into the oil when the go bad? To me, it sounds as if there is oil on the other side of the seal. I'm just trying to understand how it is that this occurrs?
The gaskets deteriorate due to poor design, and perhaps the type of coolant (Dexcool) helps accelerate this deterioration. Anyhow, the coolant can then leak down into the "valley" of the engine below the intake manifold, which is an "oil only" area. This is how the coolant gets into the engine oil and causes some real trouble. Some times the coolant leaks to the external part of the engine as well and can be seen as a dried, orangish crust in those areas.
Is GM now reimbusing folks for these repairs? Seems like that is what I read somewhere, after a class-action lawsuit by some consumer group.
Is GM now reimbusing folks for these repairs? Seems like that is what I read somewhere, after a class-action lawsuit by some consumer group.
I think I understand what you are describing bmwtechguy; however, I still don't completely undertand. When I think of a manifold, I think of an exhaust manifold... But you are saing there is an oil intake manifold? Located on the back of the engine between the firewall and the engine? Is that where it is?
I wish I could find a diagram of what happens when antifreez leaks down into this area.. ??
I wish I could find a diagram of what happens when antifreez leaks down into this area.. ??
BTW, it's not always obvious you have a problem until the engine starts making lifter tapping noises or worse. I have heard that it's not WHETHER your engine will get the problem or not, it's WHEN. I have seen issues as early as 40-50k miles. Keep an close watch on coolant level, etc.
Originally Posted By: bmwtechguy
BTW, it's not always obvious you have a problem until the engine starts making lifter tapping noises or worse. I have heard that it's not WHETHER your engine will get the problem or not, it's WHEN. I have seen issues as early as 40-50k miles. Keep an close watch on coolant level, etc.
Yes, I have been doing that... I purchse the car with 50k and the gaskets were replaced the week a bought it, it now has 140k and 8 years later. I noticed the coolant level dropped in a 6 month period just slight below the cold line. It only took like a half cup to bring back to level. That said..When I first start the car in the morning when engine is cold, the engine makes a lot of tapping noises, but not sure if it is lifters that I am hearing. As soon as the engine warms up or I start driving it, this sound goes away. Also, after the engine is warmed up and I get out whie still running, It runs very quiet.
This noise I'm hearing...could that be lifters I'm describing?
It sort of sounds like a "click clack click clak" LOL How's that? I wish I could put a soundbite up on there so you could here it. As it steted, it goes away as soon as you throw it in drive or the engine is warm.
If it were a lifter..would it continue to make that noise?
BTW, it's not always obvious you have a problem until the engine starts making lifter tapping noises or worse. I have heard that it's not WHETHER your engine will get the problem or not, it's WHEN. I have seen issues as early as 40-50k miles. Keep an close watch on coolant level, etc.
Yes, I have been doing that... I purchse the car with 50k and the gaskets were replaced the week a bought it, it now has 140k and 8 years later. I noticed the coolant level dropped in a 6 month period just slight below the cold line. It only took like a half cup to bring back to level. That said..When I first start the car in the morning when engine is cold, the engine makes a lot of tapping noises, but not sure if it is lifters that I am hearing. As soon as the engine warms up or I start driving it, this sound goes away. Also, after the engine is warmed up and I get out whie still running, It runs very quiet.
This noise I'm hearing...could that be lifters I'm describing?
It sort of sounds like a "click clack click clak" LOL How's that? I wish I could put a soundbite up on there so you could here it. As it steted, it goes away as soon as you throw it in drive or the engine is warm.
If it were a lifter..would it continue to make that noise?
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On some engines, the intake manifold seals both coolant and intake air passages. But if coolant finds its way past this seal, it can go into the air intake passage (not common), outside the engine (common and can usually be seen as described above), and inside the engine drains down the valley due to gravity and eventually mixes with the oil, causing sludge to form. The intake manifold covers the valley where the pushrods and lifters can be seen when it is removed. This area under the intake is part of the crankcase system and an oil-only area.
The other design is when you have an upper and lower intake manifold. Usually the upper one is some type of black-colored plastic and is for intake air only. The lower intake manifold (LIM) is then a separate manifold directly under the upper one, and is the effective "cover" of this valley area and provides the seal from the outside world for the crankcase/oil valley area. This LIM also has coolant passages to the clinder heads on either side and when the LIM gaskets leak, coolant can then leak directly down (internally) into the valley and contaminate the crankcase/oil system. I'm sure there are pictures somewhere online, but this is the best I can explain without pictures.
The other design is when you have an upper and lower intake manifold. Usually the upper one is some type of black-colored plastic and is for intake air only. The lower intake manifold (LIM) is then a separate manifold directly under the upper one, and is the effective "cover" of this valley area and provides the seal from the outside world for the crankcase/oil valley area. This LIM also has coolant passages to the clinder heads on either side and when the LIM gaskets leak, coolant can then leak directly down (internally) into the valley and contaminate the crankcase/oil system. I'm sure there are pictures somewhere online, but this is the best I can explain without pictures.
Thanks....
As for the noise I'm hearing upon cold start up...sort of a real fast..clack clack clack type sound which goes away when I start driving or the engine is warm... Do lifters stop making noises like this once it's warmed up? Or if the lifter is bad, would I continue to hear it?
As for the noise I'm hearing upon cold start up...sort of a real fast..clack clack clack type sound which goes away when I start driving or the engine is warm... Do lifters stop making noises like this once it's warmed up? Or if the lifter is bad, would I continue to hear it?
Yes, sounds like start-up lifter noise, but not necessarily due to coolant ingression. Does it last more than a few seconds or maybe 15 seconds? Then I would be more concerned. However, even small losses of coolant are suspect. Check the water pump weep holes first, to make sure you are not leaking there.
I had one with one continuous loud lifter tap and all the signs (slight coolant loss, etc)-even the oil had a very orange tint, but had not gotten to the emulsion-looking stage. We changed the oil and filter, then added a strong engine flush and ran it up to 2000 rpms for about 20 minutes. Lifter clap went away and never came back after changing the LIM gaskets on that 2003 Buick Rendzvous 3.4L (less than 50k miles). Of course we changed the oil a couple of short intervals after all that to flush it out some. It's still going strong several years later.
Those LIM gaskets have been revised several times over the years and we have seen several cars have them replaced only to go bad again. Seems like the most recent gasket design was the one that really fixed the problem, but it did not come out on the new cars until 2004 or thereabouts. There's lots of discussion on the Net about this if you do a search. Fel-pro has a good one now, IIRC.
I had one with one continuous loud lifter tap and all the signs (slight coolant loss, etc)-even the oil had a very orange tint, but had not gotten to the emulsion-looking stage. We changed the oil and filter, then added a strong engine flush and ran it up to 2000 rpms for about 20 minutes. Lifter clap went away and never came back after changing the LIM gaskets on that 2003 Buick Rendzvous 3.4L (less than 50k miles). Of course we changed the oil a couple of short intervals after all that to flush it out some. It's still going strong several years later.
Those LIM gaskets have been revised several times over the years and we have seen several cars have them replaced only to go bad again. Seems like the most recent gasket design was the one that really fixed the problem, but it did not come out on the new cars until 2004 or thereabouts. There's lots of discussion on the Net about this if you do a search. Fel-pro has a good one now, IIRC.
The hydraulic lifters have some of the smallest oil passages/clearance in your engine. That is why oil problems tend to show up there first and give you some warning with all the racket. Lifters should not go bad- there's a reason usually. If you are getting contamination of the oil with coolant, it can block or partially block some of the oil flow in the lifters, causing excessive valvetrain clearance and the noise you hear. As the oil warms up, it then can fully fill the lifter and noise can go away. When the lifters are clacking, yes there is gonna be some extra wear on the lifters/cam/pushrods, depending on how bad it is. If it is due to coolant contamination, and you fix the problem, the lifters can usually be brought back to a better state with a quick acting flush or a 500-1000 mile cleaner such as Schaeffers Neutra, or even some Auto-RX for 3-5k miles. I have used all of these in different situations. They are all effective products.
It's probably piston slap. Very common in the 3.1, my mom's does it and everyone else I know that has a 3.1 has a piston slap issue.
Without hearing the noise and how bad it is, I don't know how much to be concerned. I do know that low oil pressure or partially blocked lifter passages can cause these startup lifter noises that eventually go away. Yes a whole minute of lifter noise would have me concerned and looking for the cause and a solution. Is the noise any less when the oil and filter are newer vs getting near oil change time? or when the engine is already warmed up? My guess is that noise is worse and lasts longer the longer the engine has sat still and the colder it is. Try a different oil filter perhaps and see if it is any better. Sometimes he ADBV design is better on a Wix/Napa Gold oil filter, and may help keep more oil in the system for cold starts.
Ok, yeah that makes more sense. Piston slap. What oil and filter are you using, stromboy? How long has the noise been coming on?
Not sure much can be done for a piston slap issue-possibly a different oil could help some.
Not sure much can be done for a piston slap issue-possibly a different oil could help some.
Originally Posted By: bmwtechguy
Ok, yeah that makes more sense. Piston slap. What oil and filter are you using, stromboy? How long has the noise been coming on?
Not sure much can be done for a piston slap issue-possibly a different oil could help some.
Well, I use Purolater filters and I've been using conventional Pennzoil and Valvoline... It's made this sound for the past 60-80 thousand miles each time I start when cold.. What is pistion slap?
Ok, yeah that makes more sense. Piston slap. What oil and filter are you using, stromboy? How long has the noise been coming on?
Not sure much can be done for a piston slap issue-possibly a different oil could help some.
Well, I use Purolater filters and I've been using conventional Pennzoil and Valvoline... It's made this sound for the past 60-80 thousand miles each time I start when cold.. What is pistion slap?
Just 9 months ago, i repaired my intake manifold gasket on the GM Holden 3.8litre v6. My only symptom was oil in the radiator ! I would find it under my radiator cap. Got a new radaitor, flushed and still came back. Yet i would not find anything in my oil(looked clean). Its the nature of the valley gasket, under heat, the the block is cast iron and the intake in Alluminium, it moves. Very poor design, but newer upgrades gasket and heaps of Permatex Blue should slow it down. And in the last 9 months, no more white stuff under cap. It all occured same time i needed to replace my water pump.
I can understand what you are saying though, there is no reason that oil should be coming into contact with the gasket, seems it may in region where pushrods are.
I can understand what you are saying though, there is no reason that oil should be coming into contact with the gasket, seems it may in region where pushrods are.
Piston slap is usually noise caused by extra clearance between the skirt of the piston and the cylinder wall and mostly happens when the engine/pistons are cold. The noise is due to the slight rocking of the piston in the bore as it goes through its motions. After things warm up a bit, everything fits tighter and the noise goes away. Annoying noise, and some engines are known for it. Not sure that I would worry too much about it if that is the noise you are hearing for the first minute.
I had a bad intake manifold gasket leak with this engine at 100,000 miles in year 2000. The mechanic had it apart in pieces on the floor, and he called me in to look at it. There was sludge an inch thick in some places.
It was $1200 repair, but with several small repairs thrown in. Made some more noise after, a valve or two was never the same.
In this case I think it's a bad design on GM's part if there's a higher than normal incidence of these failures. Don't think changing coolant or oil type would help too much. Changing the coolant more *OFTEN*, maybe.
It was $1200 repair, but with several small repairs thrown in. Made some more noise after, a valve or two was never the same.
In this case I think it's a bad design on GM's part if there's a higher than normal incidence of these failures. Don't think changing coolant or oil type would help too much. Changing the coolant more *OFTEN*, maybe.
Originally Posted By: strombony
Originally Posted By: bmwtechguy
Ok, yeah that makes more sense. Piston slap. What oil and filter are you using, stromboy? How long has the noise been coming on?
Not sure much can be done for a piston slap issue-possibly a different oil could help some.
Well, I use Purolater filters and I've been using conventional Pennzoil and Valvoline... It's made this sound for the past 60-80 thousand miles each time I start when cold.. What is pistion slap?
If it has made that noise for 60-80 thousand miles, then don't worry about it. All engines with some age have start up noise.
Originally Posted By: bmwtechguy
Ok, yeah that makes more sense. Piston slap. What oil and filter are you using, stromboy? How long has the noise been coming on?
Not sure much can be done for a piston slap issue-possibly a different oil could help some.
Well, I use Purolater filters and I've been using conventional Pennzoil and Valvoline... It's made this sound for the past 60-80 thousand miles each time I start when cold.. What is pistion slap?
If it has made that noise for 60-80 thousand miles, then don't worry about it. All engines with some age have start up noise.
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