Once again...intake manifold bolts
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Le Mans Master
Joined: Feb 1999
Posts: 6,807
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From: Hoosier
Cruise-In III Veteran
Once again...intake manifold bolts
I pulled my manifiold off to do some experimental work on it and saw that oil had been passing by. That also easily explained my blue puffs and oil loss last year.
What is the proper..or best way...to insure the intake manifold won't allow any oil to pass by the bolts? I recall reading to just use a thin smear of the black silicon around the water passages and nothing at the blue line sealer on the intake gasket. And to use the black silicon on the bolts? But exactly how? Do you coat the threads and then put the bolts in? Doesn't that upset the torque readings?
Please explain...I don't want to go through the leaky situation again.
What is the proper..or best way...to insure the intake manifold won't allow any oil to pass by the bolts? I recall reading to just use a thin smear of the black silicon around the water passages and nothing at the blue line sealer on the intake gasket. And to use the black silicon on the bolts? But exactly how? Do you coat the threads and then put the bolts in? Doesn't that upset the torque readings?
Please explain...I don't want to go through the leaky situation again.
Burning Brakes
Joined: Dec 2000
Posts: 1,183
Likes: 2
From: Des Moines Iowa
Re: Once again...intake manifold bolts (AlwaysWave)
Must make certain that the bolt holes are clean and dry. Suggest you start by running a 3/8" N/C tap in each hole to clean it, then use brake parts cleaner to spray into each hole, and blow dry with air compressor. Clean each intake bolt, using wire brush, then brake parts cleaner, and then when installing intake / bolts, use permatex 2 on each bolt, coating the lower 3/4" of threads on each bolt, then install and torque to specs using several incremental steps, and let manifold set a day, then re-torque, start and run engine until warm, let cool then re-torque one more time and you should not have any oil coming up through the intake bolt holes. Suggest you follow manufacturer recommendations on use of sealer for intake and lifter valley sealing. Been said many times on forum to not use the lifter valley gaskets, and use RTV silicone on both ends, about a 1/8" bead. Believe most suggest using RTV around the water passage holes on intake gasket, and some suggest use of a different sealant around intake port passages, while others say to use nothing for the intake port area.
Race Director
Joined: Apr 2000
Posts: 17,676
Likes: 201
From: Who says "Nothing is impossible" ? I've been doing nothing for years.
Re: Once again...intake manifold bolts (john's '81 mouse)
Incorrectly aligned intake gaskets can cause the same problems.
Make sure you drop the intake straight down and the gaskets don't
move.
If you are sure it's the bolts then use a non hardening goop like
Permatex No.2 I use it and never had a problem :D
Make sure you drop the intake straight down and the gaskets don't
move.
If you are sure it's the bolts then use a non hardening goop like
Permatex No.2 I use it and never had a problem :D
Race Director
Joined: Apr 1999
Posts: 10,866
Likes: 717
From: Beverly Hills/Pine Ridge Florida
Re: Once again...intake manifold bolts (john's '81 mouse)
John has it right in my opinion. I use Permatex or the old Indian Head Gasket Shellac on the bolts. I HATE silicone gasket sealer. Here's a thought..something to check when you have the intake off....check the mating surfaces of the intake and the heads for "flatness". Also, if your block has been decked, and/or your heads "shaved", the "V" created between the heads MAY NOT match the "V" on your intake manifold. I've seen some so bad that the intake has to be machined to achieve an accurate mating surface between the intake and the heads. Gobs of silicone will not correct an ill fitting intake, and you'll continue to suck oil from the galley. Hope this helps. Chuck
