Thread sealing compound or not???

[JPDIII]

Hi Folks,

Kind of a stupid question I have here...but still...

I'm about to change a cracked head on my 96 Beretta (2.2 L4). GMP 96-L-1 repair manual indicates that "GM will call out those fasteners that require thread lockers or thread sealant."

They say nothing about coating head bolts with thread sealant....as opposed to the Chilton book which explicitly recommends to "Coat the cylinder head bolts with sealing compound and install them finger tight".

Any suggestions???

[jsgold]

Hopefully someone will add from their experiances as I have not done a 2.2, but, we just did my dad's 89 Olds 2.5 a while back and I was confused about that myself. The GM service manual said NOTHING about sealing the bolts, only that they had to be tightned a special way with one bolt being slightly different as far as torquing went. I noticed though, that the head bolts I bought had thread compound on one, which was the bolt that entered the water jacket. This was also the one that was not tightened as much. I was advised not to add any other sealant and car turned out fine. I would suggest buying new bolts if you have not already done so. My late neighbor, who was a auto mechanics teacher told me on a 2.2 you HAD to replace them. (we had to replace a broken head bolt on a 2.2 some years back on my son's old 89 Beretta.) I would bet any bolts needing this will already be coated. Hopefully the book would advise you for sure somewhere along the way or someone else can tell you for sure. I think proper torque is more important unless you have bolts entering a water jacket...

[JPDIII]

Thanks for your input,

It may seem like an odd question but I'm asking this because I was very surprised to find the bolts dry and clean when I removed them. They looked as if they had never seen a Permatex coating in their
entire life in the engine block (the car showed 100.000 miles on the odometer !!!). Something you don't experience with GM engines of previous generations.

If you add the lack of explicit instructions on the subject in the GMP repair manual you end up with....well... a few doubts.

[Blue Bowtie]

I had no such instructions when replaceing the head on my 134" four-holer. I used new bolts because they are a torque-to-yield installation. I tapped and cleaned the deck:



and applied Loctite/Permatex PST sealant:



and have had no problems in two+ years of use - No DexCool leaking out, and it anything would leak, that would.

[richtazz]

The only bolts needing sealant are those that go into the water jackets. If you're not sure which ones do, coating them will not harm anything. The sealant will help lubricate the threads, resulting in a more accurate torque reading, just make sure you get everything buttoned up before the sealant sets up.