2001 silouette gaskets

[radiofixer]

Hi all,

Just started a replacement of head and intake gaskets on my 2001 0lds silouette. Am I correct in assuming the exhaust must be unbolted before the engine can be rotated ?

Thanks

[roadrunner2]

Originally Posted by radiofixer

Hi all,

Just started a replacement of head and intake gaskets on my 2001 0lds silouette. Am I correct in assuming the exhaust must be unbolted before the engine can be rotated ?

Thanks

Apparently not. At least my Haynes manual doesn't mention it.

[radiofixer]

Thanks for the fast reply. I just rotated the engine and it aparently did not break anything.

The lower intake gasket looks OK, does not seem to be leaking, so the head gaskets probably need replacing, I'm 90% there anyway. The air was constantly in the coolant causing the car to overheat. I had no oil or coolant leaks, just air that could only be bled for for a short time before its back. I would imagine that the heads are pumping air into the system.

This thing is a nightmare to get apart, the engineers must have been drunk. It was probably designed for ease of assembly on the line, not for the repairs a mechanic would make.

OH WELL!!!

[radiofixer]

There are breaks in the lower intake gasket on the left end of the engine at the water jacket opening on both sides. The plastic gasket and embedded seal are cracked and torn. I don't know if there is enough pressure in the crankcase to have cause continuing air in the cooling system, but these gaskets are definitely bad.

The heads look like a real problem to get off. There is not a bunch of room for tools to loosen the bolts on the manifolds and shields. I am thinking of just doing the upper and lower gaskets and just see if it will be OK.

Anyone have any thoughts on only replacing the bad lower intake and buttoning it all back together? I know the heads should be done also, but maybe I could get lucky.

[roadrunner2]

I didn't need to have the heads removed on my 3.4 as I caught the coolant leak the day it started. (I was very aware of the LIM gaskets breaching) So, I can't advise you.

You're correct with the 'ease of assembly on the line' comment.

The chassis is lowered over the engine during assembly.

I hope they gave you the 'new revised' GM LIM gasket kit. It finally was released in Feb/03.

Two questions (you may have already mentioned this) : were you slowly but steadily losing coolant from the coolant reservoir before you decided to do this gasket repair?

If so, how long did you drive it after you noticed the coolant loss?

If you never drove it long (if over-heating) and there was/is no odd engine noise, likely there is no bearing damage.

[roadrunner2]

radiofixer,

Are you following the IMG repair post 97ventureowner posted (in red at the top of the page)?

[radiofixer]

I am down to the heads removal. Every time I think it's going OK something else pops its ugly head. The only thing keeping me going is I really like the vehicle (when its working), and I cannot afford to get it fixed or replaced. I have been out of work for 7 months, so I have to fix it. Actually this is the very first major repair since new in 2001.

I can probably get the front head off with some swearing and cussing, but the back one will put me in the mental ward!

I read all these post where they say "just rotate the engine and you will get it done easily" are they kidding? I have read the article about LIM replacement, I wish that was the only thing I had to do, I would be finished already. But not being sure that the head gaskets are not blown necessitates their change. Also what I have read is they will blow anyway, there is 90k miles on the car.

Thanks for your advice, I really appreciate it.

[roadrunner2]

Sorry to hear you're unemployed. Too much of that lately.

I know what you mean about little space to work even with the engine rotated.

This is why it takes 6 hours to replace the LIM gaskets. It takes major time to remove all the brackets/hoses/emissions crap in order to get to the gaskets.

Guess what my independent tech told me when I asked how much it would cost to replace a leaking oil pan gasket on this van.

Sit down if you're standing. It cost the SAME as the LIM gasket replacement as there is (AGAIN) a lot of stuff to get out of the way.
I almost fell over.
When the van was up on the hoist I had a look at the oil pan gasket and found it isn't physically leaking oil out, only 'sweating'. The pan perimeter is damp.
I'm thinkin' that baby's gonna sweat for a looonnnnnnggggg time.

You're right, you don't want to stop with just replacing the LIM gaskets , button it up , THEN worry as to whether or not there is damage further down.

If you take the heads off, (you likely know this already, but...) have them planed for true and inspect the crankshaft bearings while the heads are off.

[radiofixer]

Oil pan leaks are very common. Most times it is because of pan bolts loosening because of gasket compression, sometimes just snugging them up will help. I hope I don't have to that also in the future on this engine. When I was a kid, and the pan leaked it was easy job to replace the gasket. Of course that was a time when cars were made to work on.

I think the next time I have to do any engine work to this van I will rig up a body hoist so the sub frame can be unbolted and separated from the engine. The next job will be the timing belt, I cannot do it right now because of money and time restraints, but the mileage of the vehicle dictates it should be done soon. I don't know yet if it can be done in the compartment.

Well, now I have to go out and clean all the mating surfaces, drill and easy out a broken exhaust stud, and start putting it back together. I do not have the money right now to have the heads done, so I will have to have some faith that it will be OK. The rear exhaust manifold is the pain, you cannot see what you are doing.....Valium here I come!

[roadrunner2]

These 3.4L V6s have timing chains, not belts. It'll likely last longer than you will.

Good luck putting it back together.

Don't forget to use the proper torque valus and hopefully end up with nothing left over.

[roadrunner2]

Originally Posted by roadrunner2

These 3.4L V6s have timing chains, not belts. It'll likely last longer than you will.

Good luck putting it back together.

Don't forget to use the proper torque values and hopefully end up with nothing left over.

This edit thing here is weird. Now, I originally spelled 'values' without the letter 'e'. that's the only correction I wanted to make.

[radiofixer]

Well... The heads are back on. the exhausts are bolted back, PHEW!
All are torqued to specs.

I did have a mishap, my grandson mixed up the pushrods, he thought they were pickup sticks! I have looked everywhere but cannot find out which size is the exhaust and intake rod. I want to button this up but do not want to bend a valve.

Anyone know ?

[roadrunner2]

Originally Posted by radiofixer

Well... The heads are back on. the exhausts are bolted back, PHEW!
All are torqued to specs.

I did have a mishap, my grandson mixed up the pushrods, he thought they were pickup sticks! I have looked everywhere but cannot find out which size is the exhaust and intake rod. I want to button this up but do not want to bend a valve.

Anyone know ?

Kids. Gotta love 'em eh?

Maybe your youngster is mechanically inclined?

You're not going to believe this, but I spent almost 1/2 hour last night typing the sequence of events as to your previous queries on the fuel pressure regulator.

Well, when I hit "submit', it all took a nosedive. I couldn't remember my old password and couldn't get back on. Bah! Anyway, all is good now.

I see you managed to almost finish.

One thing though: when you installed the fuel pressure regulator again, did you attach the fuel return line BEFORE you tightened the regulator down. If not, there is a chance you may wind up with a fuel leak.

Did you find that before you installed the new O-ring you were to lightly lube it with engine oil.

I hope I can get this typed before it disappears again.

Intake and exhaust pushrods are different lengths.

Intake pushrods are approximately 5 3/4" long, while exhausts are 6".OEM pushrods are color coded yellow for intake and green for exhaust.