legacycentral bbs

I decided to do a head gasket job on my legacy... I took my time, and over a month later it's all back together. i started it up today and there are still air bubbles that come up from the bottom of the coolant reservoir... that is exactly what it was doing before i did the head gaskets. the car runs fine and pulls alot harder becuase i also did a valve job on the heads. but, it was also running good the first time that i saw bubbles, then while i was on the way to get the coolant "sniffed" it started to run bad (lack of compression) so i turned around and went back home and started taking it apart.
so right now, if the bubbles don't stop, i guess i should be expecting total head gasket failure again... i don't get it... any thoughts??? at first i thought it could be air bleeding out of the system from filling it....but its been doing it all day...there shouldnt be that much air in there...i used the bleed screw....

Did you have the surfaces checked and machined if needed? No reason to just replace the gasket if the mating surfaces are damaged. I feel your pain though, my supra had something like this happen.

Just to make sure maybe you should get the coolant sniffed.

i had the heads milled... but as for the block... i don't know...it's overheated once before, but not bad, and that was like 2 years ago, so it seems unlikely that the head gasket issue has anything to do with that overheating incident. so its unlikely that the block is cracked. no visible cracks at least. I might try to re-torque the head bolts in a couple days and see if that does anything.

let me guess, having the coolant sniffed is to take it to some one that will survey it to see if it has carbon monoxide or something?????
. hope you figure it out man.

Both the heads and block are aluminum, so it's possible that overheating the engine warped the block and the heads. As long as you're sure you got all the air bubbles out of the coolant after replacing the head gaskets, it sounds like your problem still exists.

Rob

You can get a kit to sniff the coolant yourself. Its a little thing that screws onto the rad cap. Inside is a chemical that changes color when exhaust gas is present.

petridish38 wrote:I might try to re-torque the head bolts

Did you use the correct head-bolt torquing procedure? There are specific torque specs you have to use. What you end up doing is torquing them down too much to stretch them slightly, loosen them and then torque them down to factory specs. This allows the head to seat correctly against the gasket. This is also why you should use new head bolts.

If you did this incorrectly, then you can easily cause another gasket leak or blow the gasket.

we used the chilton's manual to do the torque. it says to torque them in order....then go around again with more torque in order... once they were torqued, it said to loosen them 180 degrees in order...then another 180 degrees. then torque them down....then once torqued, it says to turn them in sequence 80-90 degrees....then another 80-90 degrees. we followed that as closely as we could... the easiest thing to do would be to loosen then in the loosening sequence and retorquing them....