Permatex #2 and Head Gaskets

[fixmyevinrude]

1993 225 HP Johnson. My neighbors engine developed a head gasket leak while on vacation. He bought new gaskets and replaced both engine banks. He did not have a torque wrench so he did the best he could with a socket wrench. Well it seemed to work fine. My question is this. He used Permatex # 2 on both sides of the head gasket before installing it. Will this hurt anything? He also put Permatex on the Head bolt threads. I told him at the very least he should buy a OEM Manual and retorque the headbolts to the correct Value. What can he expect by useing the permatex and what should he have used if anything?

 

[Cofe]

Re: Permatex #2 and Head Gaskets

You are right.
Head gaskets don't need any sealant.
Using permatex on bolts may cause them to gald.
Gaskets are crushed to the proper seal when the head is torqued properly.
You can expect to have a "pita" when the head is removed in the future.

 

[daselbee]

Re: Permatex #2 and Head Gaskets

The torque value is 15-17 ft-lbs in case you were wondering.

 

[fixmyevinrude]

Re: Permatex #2 and Head Gaskets

Thanks for the answers. I like the "Pita" answer. I am going to help him torque them to the correct values. I will assume Permatex wont hurt anything as far as the the gaskets go. I was only concerned for him because I know I have read posts that #2 is not the perferred sealant for outboards and in some situations people use Aviation sealant. I believe it is #3.

 

[jtexas]

Re: Permatex #2 and Head Gaskets

Myself, without the factory shop manual in hand, I'd go with Cofe's advice. I can't speak with any authority about that specific model engine, just be aware there's differences year to year, model to model, and gasket-to-gasket. The manual for my (considerably older model) 'rude calls for OMC gasket sealant on the head gasket, unless the replacement gasket itself indicates otherwise.

Another reason for torque measurement: potential for warping if all the fasteners aren't the same tight.

 

[parrisw]

Re: Permatex #2 and Head Gaskets

If it were me, I'd redo the whole job. Clean it up and start again. He may very well have over torqued the bolts rendering the gaskets useless, gaskets are cheap and it's and easy job to do. You don't want to have future problems due to taking shortcuts. I realize you gota do what you gota do in a pinch to get the job done, but when you have the chance it needs to be done right.

 

[Cofe]

Re: Permatex #2 and Head Gaskets

Once a gasket is over torqued, there is no loosing up and retorque. The purpose of torquing a head gasket is to crush the metal circles in the gasket. Once they are over torqued, the metal is already crushed to the original applied force.
Henceforth a new head gasket, without sealant, and at the proper torque is required for a proper seal ...... otherwise, the head gasket could prematurely go at any time.... As far as head bolts, chase the holes and use oil on the threads. Do it right get a OEM manual preferably a OMC..... you can find them on ebay.

You're friend's boat motor deserves a friend like you. Do it right

 

[14ftgrumman]

Re: Permatex #2 and Head Gaskets

No sealant. Gasket goes on clean and dry.

Don't even THINK about changing head gaskets without a manual and a torque wrench (inch/lbs preferred)

 

[James R]

Re: Permatex #2 and Head Gaskets

Take it down and clean all the *** off. Run a tap down the block threads and a die down the bolts. Don't use some cheap tap and die from China. Use US or Euro made tools to maintain thread integrity, new bolts would be good but not essential. A little antiseize on the bolts wont hurt but be careful to torque just below maximum. New clean gaskets are of course essential. After a few hours running check the torques.

 

[fixmyevinrude]

Re: Permatex #2 and Head Gaskets

When you check torque values do you back the fastener off to retorque it are just continue forward untill the correct value is attained?

 

[14ftgrumman]

Re: Permatex #2 and Head Gaskets

Don't loosen them up, you are making sue that the bolts didn't back out. Retorque them in the proper sequence, also.

Yes, there is a torque sequence. You just don't start at the top and work your way down.

 

[daselbee]

Re: Permatex #2 and Head Gaskets

You will notice that the head bolts are numbered..stamped right on the head next to the bolt. #1 is in the middle, and you work out from there. I start with 10 ft-lbs on the first pass, then finish with 17 ft-lbs on the second pass.

 

[fixmyevinrude]

Re: Permatex #2 and Head Gaskets

Thanks for all the info. I just finished up helping retorque the head bolts. I cant convince him to start over with clean gaskets and see what the manual says. He has a manual on order. Suprisingly all the head bolts seemed to be about 12 to 14 ft.lbs. He told me he made all the bolts finger tight and then turned the wrench about 180 degrees then went back and added another 45 degrees. He saw the numbers on the head and figured they were for the torque sequence.