Engraver

Got the motor running this weekend
but there are a couple of coolant leaks. It appears to be oozing around some head bolts just above the headers. Is this possible? Are some of the head bolts in commutation with some coolant runners? My engine builder bolted the heads on. If he didn't use sealant on the bolts could this happen? This is a BB 427 with AFR heads.

feb18blacksunday

I think he left off the Permatex.

page62

Yep. No sealant. My GM Performance Products head bolts came pre-gooped with sealant (thank goodness).

Engraver

So what should be done now? They aren't leaking much but they are sure leaking. I suppose they are also probably leaking around the head bolts under the valve covers too? At this point should the coolant be drained and then remove one head bolt at a time, goop it with Permatex#2 and screw it back in, torque it and go on to the next bolt? If I knew which bolts went into the coolant runners I would only have to do those.

Or I could do a cheap Babba fix and dump in some of the copper radiator stop leak stuff. That would be too easy... How does that stuff get along with aluminum heads?

FB#1

Unfortunately, yes, you have to take them out, permatex them and then torque them back in.

MotorHead

Any chance you can drive it over to the engine builder and let him fix it ?

If not you might get away with doing one at a time and retorquing, if that doesn't work the heads gotta come off and new head gaskets and retorqued

Engraver

I just talked with the engine builder that bolted the heads on. He said he used that aviation goop on the head bolts. He said if it is leaking around one of the bolts to use some of the stop leak radiator stuff.

I mentioned to him I could remove the leaking bolts, goop them and re-torque but he still recommends the stop leak...

Now I'm not sure which to do. I don't really like the idea of putting that stop leak stuff in my new motor.

virg74

I would drain the coolant remove one bolt at a time and use #2 black permatex then retorque. Then never go near that builder again!!!

Good Luck

Engraver

Could there be some head bolts under the valve covers that also could be leaking? Or are the only bolts that go into a coolant gallery a few of the outside ones? It would be nice to know which ones do and those that don't. Anyone know which are which?

Engraver

Removed the valve covers to take a look... sure enough coolant is in there too.

rihwoods

"Then never go near that builder again!!!"

Amen to that.Only use stop leak in a pinch on the road or something.But not ever in this case.Your builder is a #$%&^*@$.

Engraver

Thanks to everyone for the help with this!

Can anyone inform me if the lower head bolts (the ones below the exhaust ports) are in communication with the coolant galleries? If none of them are then I won't have to take the hooker headers and side pipes off. Anyone know?

stingr69

All of the head bolts are in water so they all gotta come out.

-Mark.

mrvette

IF that's the case, i'ts crappy design work on GM's part....GOG knows they are famous for this screw up....


case closed....


GENE

Budman68

If you are using aluminum heads, switch to the orange Texaco coolant also. I had all kind of leak problems on my TPI motor with the green, switched to orange and all gone. I did have to reseal a few bolts in the intake.

Engraver

Yep... I've got the green coolant in there. Why would the new orange coolant leak less?

carhound

Don't use the radiator sealant, to me that is just masking the problem. the builder did a crappy job. Make him take the heads off and do it right.

Russ Bellinis

I'd stay away from Dexcool (orange coolant) there have been a lot of bad issues with that stuff. A friend, who owns a shop and gets all of the trade publications has noticed articles in all of the mags advising mechanics to drain and flush cooling systems to get rid of Dexcool on any cars they work on. I also would not reccommend removing one head bolt at a time. Your aluminum heads are not cheap. Your engine builder should fix it; but if he won't stand behind his work, pull all of the head bolts on each bank, goop them, and reinstall them. He may say he put goop on the head bolts, but that isn't good enough. A reputable builder will guarrantee against leaks, not just assure you that he put the sealant on the bolts. Aluminum heads are much more prone to warping than steel heads. They give you a torque pattern for heads and advise torquing in sequence in at least three steps to keep heads from warping. Taking a short cut with head torque is asking for trouble in my opinion. You have to remove all of the head bolts anyway. That means removing rocker arms as well, so you have to go all of the way to the heads regardless. I think you can remove all of the head bolts without disturbing the intake manifold or exhaust headers. You shouldn't have to remove the heads or damage the head gasket. When you have finished redoing everything, after you put coolant back in and start the engine, and after you have run it at 2000 rpm for the first 20 minutes for cam breakin, change your oil as well to get rid of all of the coolant that may have gotten into the pan.

Engraver

The bolts are ARP studs with a nut on the top. Should the studs that screw into the block also be sealed? or is it just the nut on the top that should have been sealed?

Engraver

Thanks again for the help with this!