Engine is a 355 SBC...installed about 8 months ago. Runs great, oil pressure stays between 35-40 when cruising, water temp stays at 190. This started about a month ago and and is at both corners on passenger and driver side. The seeping is not enough to leave any drops on the ground but I want to address the problem now because I am sure it will only get worse. I searched the site and seen opinions about re-torquing whether that should be done or not. Didn't know if I should try that first or just go ahead and replace the head gaskets. But before I did just wanted some opinions and maybe something I am missing or something else I need to do/check as well. The experience on this site is great so just looking for opinions before I start tearing apart.
SBC head bolts go into the water passages in the block. Head bolt threads should be coated with a sealant before installation. Don't know if yours were coated or not, but I would try removing one bolt at a time, coating the threads with Permatex thread sealant #80632 and reinstalling. Torque to 65 ft.lbs. May help or not, but it would be worth a try before changing head gaskets. At least you will have the right sealant for when you change head gaskets.
Its a common thing to re-torque heads on some things, Model A Fords for one. A lot depends on what gasket you used, steel shim, composition, etc. If if it was me, I'd sure try a re-torque before I tore it completely down. Maybe even a jar of Bars leak. Good Luck!
If you can see seepage on the outside can you guarantee there is no seepage on the inside? Re-torquing and throwing in a can of bars leak or a couple of GM's tablets may fix it but would it bring peace of mind?
Definitely, re-torque in correct pattern. It's a pain to remove headers and rockers, but well worth the effort.
First, the "heads" aren't seeping, the gasket is. Second, it seems that you aren't aware of retorquing after the first or second heat cycle. It may be too late after you've driven it a while. A short heat up cycle then retorque is recommended by most gasket manufacturers. Third, as has been noted, did you use a thread sealer of some sort when installing the cap screws (bolts) ? Forth, did you torque the cap screws from the center out as recommended to the recommended torque value. Fifth, did you use any sort of sealer on the gasket ? "Copper Coat" is a good spray on sealer. Sixth, were the head and block surfaces clean and dry ? And one last one...is the block deck and head deck, flat ? Mike
i had same issue with my complet rebuilt 324 engine , head gaskets were leaking like yours.. after a couple heating cycles , i retorqued the heads , and there is no more leak after that .....
There's no need to loosen them, but if the head bolts are not tightened to spec they need to be tightened to spec. It's probably more correctly called a "torque check". Set your wrench to the bottom of the torque range ft/lb spec for the application and check them all in the order of tightening sequence set forth in the shop manual. See if any move. Then set your wrench at the top of the torque spec and iterate. This should be repeated after every few heat cycles until they stabilize i.e. none of them move.
Mike- I guess I should have mentioned I did not rebuild this engine. I bought the short block and put on intake, water pump, pulleys, etc. I am aware of the retorquing after a few heat cycles. I was told the head gaskets were done 5 years back on the motor but all I could do was take the gents word for it. I was going to try retorquing and checking for sealant on threads, but to go this route I figured might as well take another couple days and do the head gaskets while I am at it. That will tell me the answers to the rest of your points. Thanks for all the input.
Did he say that they were Fel-Pro somewhere in the posting? If he did it's been edited and no longer says so.....
Never been a fan of fel-pro head head gaskets. I've always used steel shim head gaskets with the GM gasket cement on the gasket's and head bolt threads. Yeah... I know... call me crazy... (this is for iron to iron, of course... ) Never had a leak or seep problem either.
I never use thread sealer on head bolts . I was always concerned with causing incorrect torque readings . But I maybe in a fog also . Looks to me as yours have been leaking to long to retorque . I would tear it down , check the head for flatness . If all is well reassemble with new no retorque gaskets and wish it well . Also verify if thread sealer is needed Chebby head bolts after checking head bolt length for stretch length , you may need new bolts also . Every piece of hardware we purchase today , is China made . I just purchased ARP head studs for my Cummins , were to be torqued at 125 ft lbs . I had to mill rocker stands to install , 4 hrs labor . The first two that recached 90 ft lbs ., stripped the nuts . I contact ARP “your torque wrench is incorrect “ . Well I have 2 and I guess both are 35 lbs off ! Ha ha ! Just beware things are not as they were made 30 years ago .
I agree with you with China made bolts... I ordered coated ARP bolts for my intake and same thing happened. Had torque set 5lbs below spec and snap the ARP bolt. Same deal, called ARP and my 'setting was off'. Needless to say, I will not be using ARP bolts anymore.
Where were those ARP fasteners bought from? Counterfeit fasteners are nothing new. As is counterfeit practically-everything-else . I have no first hand experience, but I'm surprised ARP did not want you to send all the fasteners back for them to evaluate.
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