New headgasket leaking good heads and block - Third Generation F-Body Message Boards

firebird904 · 10-10-2009, 09:36 PM

I replaced all the gaskets on my lo3 after having to pull the engine to replace a cracked head i had the block checked out and the heads were checked for cracks and all was good i used the oem felpro gaskets from oreily i put the engine back in hooked everything back up and everything was good took it out for a test run and had no leaks no coolant loss. Started it today and noticed water coming out of the exhaust i knew it wasnt condensation so i took the radiator cap off and noticed there were bubbles forming i torqued the heads to 55ft lb could it be possible that a retorque would resove the problem?

1tpi · 10-10-2009, 09:57 PM

Quote:

Originally Posted by firebird904

I replaced all the gaskets on my lo3 after having to pull the engine to replace a cracked head i had the block checked out and the heads were checked for cracks and all was good i used the oem felpro gaskets from oreily i put the engine back in hooked everything back up and everything was good took it out for a test run and had no leaks no coolant loss. Started it today and noticed water coming out of the exhaust i knew it wasnt condensation so i took the radiator cap off and noticed there were bubbles forming i torqued the heads to 55ft lb could it be possible that a retorque would resove the problem?

Looks like your about to find out.

Rolling Thunder · 10-11-2009, 10:56 AM

If you just did the heads the bubles might just be from air bubbles escaping. Water in the exhaust if your positive its not condensation or something that wasnt accidentally spilled in the exhaust we can move on but be sure that it isnt. Few questions im not sure off hand what the torque spec is i thought it was higer than that but i dont remember really but there are a few other things to mention that are commonly overlooked. First did you use thread sealer on the head bolts? They go into the water jacket and will likely leak eventually if you dont use thread sealer (not to be confused with a gasket sealer its not the same stuff). Next even though the heads and block were checked for cracks what about if they were checked for flatness? If its not flat within tolerances anyways it wont seal to well. Lastly did you torque them in three correct manner? They should be torqued in a specific order and in steps of the (meaning if it was to be torqued to say 90 you torque everything to 30 then to 60 then to 90 then go around again torquing them to 90). Also torque reading are only valid if the threads in the block have been chased out with a tap and the bolt threads have been cleaned up with a wire brush. If the bolt hits any resistance from your threads being unclean or rusty your torque readings will be wrong.

firebird904 · 10-11-2009, 12:45 PM

Quote:

Originally Posted by Rolling Thunder

If you just did the heads the bubles might just be from air bubbles escaping. Water in the exhaust if your positive its not condensation or something that wasnt accidentally spilled in the exhaust we can move on but be sure that it isnt. Few questions im not sure off hand what the torque spec is i thought it was higer than that but i dont remember really but there are a few other things to mention that are commonly overlooked. First did you use thread sealer on the head bolts? They go into the water jacket and will likely leak eventually if you dont use thread sealer (not to be confused with a gasket sealer its not the same stuff). Next even though the heads and block were checked for cracks what about if they were checked for flatness? If its not flat within tolerances anyways it wont seal to well. Lastly did you torque them in three correct manner? They should be torqued in a specific order and in steps of the (meaning if it was to be torqued to say 90 you torque everything to 30 then to 60 then to 90 then go around again torquing them to 90). Also torque reading are only valid if the threads in the block have been chased out with a tap and the bolt threads have been cleaned up with a wire brush. If the bolt hits any resistance from your threads being unclean or rusty your torque readings will be wrong.

I had the heads and block checked for flatness and the bolts were cleaned aswell as the threads in the block i used thread sealer on all the headbolts but i didnt torque them in steps i just torqued it to 55ft lb could this be the problem? I looked up the specs and it says that the headbolts should be 65 ft lb

AlkyIROC · 10-11-2009, 01:10 PM

Quote:

Originally Posted by firebird904

i didnt torque them in steps i just torqued it to 55ft lb could this be the problem? I looked up the specs and it says that the headbolts should be 65 ft lb

yes

Rolling Thunder · 10-11-2009, 01:55 PM

Yea that could deffinetly cause the problem also if they werent torqued in the right order. Kinda like wheels should be torqued in a star patten the head bolts have an order they should be torqued in as well. Not to mention it was a little under torqued. All and all you did better than most taking the time to clean out the threads and use the thread sealer but I think if you do it again and torque them in 3 steps to 65 (and then go around again to re torque them to 65) in the correct order youll be just fine. Might want to get new head gaskets though even though yours are practically new I just wouldn't trust re using them but thats just my opinion. I know it kinda sucks but hey thats how we learn right.