No Perfect Seal applied to cylinder bolt threads?

fossildave · Sep 10, 2006

Just replaced head gasket on 3.0 Litre 4 cyl engine. Only put anti-seize on head bolt threads. Did not use Quicksilver Perfect Seal as shop manual suggested. (Looked like anti-seize was previously applied) Is this a fatal error? Is Perfect Seal needed to prevent water seepage past threads? If so perhaps I can remove one bolt at a time, clean and replace with proper sealant. Final torque was 130 ft/lbs per manual. I have not installed valve cover & ex manifold yet. Please post suggestions.

Gary H NC · Sep 10, 2006

Re: No Perfect Seal applied to cylinder bolt threads?

should not be a problem..the headgasket should seal anyway. i would not remove the bolts if you tightened them in the correct order.

Silvertip · Sep 10, 2006

Re: No Perfect Seal applied to cylinder bolt threads?

I'm not sure if the 4 banger head bolt holes open into the water jacket but if they do, anti-sieze is not going to stop the water intrusion. I suspect they do since Merc indicated to use the sealant.

Don S · Sep 10, 2006

Re: No Perfect Seal applied to cylinder bolt threads?

Yes, the bolts go into the water passage.
Drain the block, and pull one bolt at a time and clean the threads the best you can of the antisieze. Then seal it with the proper sealant and reinstall. Torque to the proper spec and do the next.

fossildave · Sep 11, 2006

Re: No Perfect Seal applied to cylinder bolt threads?

fossildave said:
Just replaced head gasket on 3.0 Litre 4 cyl engine. Only put anti-seize on head bolt threads. Did not use Quicksilver Perfect Seal as shop manual suggested. (Looked like anti-seize was previously applied) Is this a fatal error? Is Perfect Seal needed to prevent water seepage past threads? If so perhaps I can remove one bolt at a time, clean and replace with proper sealant. Final torque was 130 ft/lbs per manual. I have not installed valve cover & ex manifold yet. Please post suggestions.

fossildave · Sep 11, 2006

Re: No Perfect Seal applied to cylinder bolt threads?

Made another mistake as well. Referred to Mercruiser chapter on torque (130 ft/lbs) instead of GM chapter (only 90 ft/lbs). I think I had better remove head, clean bolt & hole threads, apply Perfect Seal or equivalant & retorque to 90 ft/lbs with another new head gasket.
Thanks for all the replies....

Don S · Sep 11, 2006

Re: No Perfect Seal applied to cylinder bolt threads?

Referred to Mercruiser chapter on torque (130 ft/lbs) instead of GM chapter (only 90 ft/lbs).

What manual are you using? Merc never changed any specs on head torque. And what year is your engine?

fossildave · Sep 17, 2006

Re: No Perfect Seal applied to cylinder bolt threads?

Removed cylinder head. Cleaned threads with Brake Kleen. Re-installed head with new gasket & sealed bolt threads & thread holes with Permatex Aviation Sealant. Torqued bolts to 90 ft/lbs as directed in GM section of Clymer manual. (accidently referred to Mercruiser chapter on last attempt) All is together and working fine. Thanks for all comments. Don, it was a 1990 Mercruiser inboard/outboard with GM 4 cylinder. No problems now.....

Don S · Sep 17, 2006

Re: No Perfect Seal applied to cylinder bolt threads?

Not sure what that "Mercruiser Chapter" refers to, I assume it was still a section in your Clymers manual. Probably if you look at it again you will probably notice the 130 is the CLOSE metric equivilant or just another misprint by Cylmers.

Whatever the problem, it's great that you fixed it properly.

fossildave · Sep 26, 2006

Re: No Perfect Seal applied to cylinder bolt threads?

The Clymers manual that I used had a chapter for Gen Motors 4 cyl and another chapter for Mercruiser 4 cyl. The engine in my boat is a Gen Motors. The GM chapter said cylinder head torque should be 90 ft/lbs. The Mercruiser engine chapter said 130 ft/lbs. I torqued the head bolts to 90 ft/lbs.
Do you think the manual is wrong for 90 on the GM engine?

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Don S · Sep 26, 2006

Re: No Perfect Seal applied to cylinder bolt threads?

Do you think the manual is wrong for 90 on the GM engine?

No, I think the manual is wrong on the 130 ft lbs in the Merc chapter.

Here is word for word from the Mercruiser service manual you should be using. If, you actually have a 1990 3.0L engine (boat year means nothing).

1. Place head gasket in position over dowel pins.
2. Carefully set cylinder head in place over dowel
pins.
3. Coat threads of head bolts with Quicksilver Perfect
Seal and install finger-tight.
4. To insure gasket sealing, torque head bolts in
torque sequence to 90 lb. ft. (122 N·m).
5. Install push rods, rocker arm assemblies and lifter
restrictors in their original positions.
6. Torque rocker arm nuts to 20 lb. ft. (27 N·m).

Don S · Sep 26, 2006

Re: No Perfect Seal applied to cylinder bolt threads?

Ya know, it just struck me as to what you are talking about with this GM and Mercruiser section.
The GM section is for the 3.0L 181 cu in GM engine, and that Mercruiser section is for the 224 cu. in., 3.7L 470 style engine.
What you need to do, is use the proper section for your engine.

No Perfect Seal applied to cylinder bolt threads?

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