Head Gasket Question

[MattPSU]

I have the dreaded, leaking 706 heads. There's water coming out one of the header bolts. It's no pouring out, but it is leaking slowly. There hasn't been any water in my oil - I've been keeping an eye on that - but I wanted to swap these out before I ran into more problems.

My buddy gave me a set of 862 heads that were part of a deal when he bought a truck. They were on a boosted motor that had been disassembled. They've had the gap filled and the face machined so that they could run LS9 head gaskets. (see picture for reference). From what I gather, those gaskets have a bigger bore, but hold up better in boosted motors.

When I swap these into place, should I pick up a set of LS9 gaskets, or will I be OK with the stock 5.3L gaskets since I don't plan to do anything else to this motor?

While I'm at it - what's the input on these eBay gasket kits that have all the gaskets and the head bolts for like $120?

Thanks - Matt

[crazy longhorn]

Look at the yr on the heads/vs gaskets? My 2000 5.3 had the notch that you see on the heads....on a 400 dollar valve job, I don't think there was any welding going? The heads were, no notch smooth / flat....yes he cut .060-.070 off my heads! Thank you "Scotty".. she burns pump fuel, idles like a stock ride, & will twist that old longhorn loose/ sideways at will....with 140 thou on the 5.3 shortblock! Longhorn

[BR3W CITY]

Originally Posted by MattPSU

what's the input on these eBay gasket kits that have all the gaskets and the head bolts for like $120?

Thanks - Matt

A good set of ARP head bolts costs more than $120 by itself...and they hold the two major halves of the engine together (in simplified terms obviously).
I wouldn't trust no-name hardware for anything that goes into the aluminum heads. I don't trust chinese piston rings either for that matter.

[crazy longhorn]

Yes, I run ARP bolts in my old ride....very expensive on top, but useable 3 or 4 times again! The flywheel/clutch hat bolts, from ARP are as cheap, as the TTY chit from the factory, & you can reuse the bolts...longhorn

[clinebarger]

"706" heads do not leak out the exhaust manifold bolt holes, The develop cracks in the head bolt bosses, Only certain "Castech" castings did that. Compared to shear numbers of 5.3L produced with "706" heads...Actual failures are rare.....

Some dimwit drilled to far to remove a broken manifold bolt...Is what happened.

[chuckmc8]

Originally Posted by clinebarger

"

Some dimwit drilled to far to remove a broken manifold bolt...Is what happened.

And broken exhaust manifold bolts are no problem to remove by welding a nut on the broken bolt and back them out. I would never try to drill and tap an aluminum head exhaust bolt. But perhaps my skill set isn't as good as others...

Seems like every engine I check out for donors has at least 2 broken and usually the rear on the driver side.

[clinebarger]

Originally Posted by chuckmc8

And broken exhaust manifold bolts are no problem to remove by welding a nut on the broken bolt and back them out. I would never try to drill and tap an aluminum head exhaust bolt. But perhaps my skill set isn't as good as others...

Seems like every engine I check out for donors has at least 2 broken and usually the rear on the driver side.

Yeah that works 99% of the time, Some break off too deep to weld on a nut.

However....I'm not the one who damaged his cylinder head, Wasn't there when it happened, But that is the only way for coolant to leak from a manifold bolt.

I would drain the coolant down, Put some Red "Gel" Loctite on the bolt, Torque it down & wait 24 hours, Refill with coolant & call it a day.

[bluex]

Originally Posted by chuckmc8

And broken exhaust manifold bolts are no problem to remove by welding a nut on the broken bolt and back them out. I would never try to drill and tap an aluminum head exhaust bolt. But perhaps my skill set isn't as good as others...

Seems like every engine I check out for donors has at least 2 broken and usually the rear on the driver side.

No tap needed just a drill bit an easy out an good penetrating oil will do the trick.

[boostedc10]

Originally Posted by clinebarger

"706" heads do not leak out the exhaust manifold bolt holes, The develop cracks in the head bolt bosses, Only certain "Castech" castings did that. Compared to shear numbers of 5.3L produced with "706" heads...Actual failures are rare.....

Some dimwit drilled to far to remove a broken manifold bolt...Is what happened.

Cline is dead on in this thread! This is more common than a 706 head leaking, lmao!

[bluex]

Originally Posted by clinebarger

"706" heads do not leak out the exhaust manifold bolt holes, The develop cracks in the head bolt bosses, Only certain "Castech" castings did that. Compared to shear numbers of 5.3L produced with "706" heads...Actual failures are rare.....

Some dimwit drilled to far to remove a broken manifold bolt...Is what happened.

Hey I'm your friendly local dimwit. The leaking bolts didn't have a broken stud in them and I know how to drill out a bolt without damaging the surrounding materials. Now what happened before we got the engine I can't say but the ones I drilled out aren't leaking....

[clinebarger]

Originally Posted by bluex

Hey I'm your friendly local dimwit. The leaking bolts didn't have a broken stud in them and I know how to drill out a bolt without damaging the surrounding materials. Now what happened before we got the engine I can't say but the ones I drilled out aren't leaking....

So you have "706" heads that are leaking coolant from manifold bolts?

[MattPSU]

Originally Posted by clinebarger

"706" heads do not leak out the exhaust manifold bolt holes, The develop cracks in the head bolt bosses, Only certain "Castech" castings did that. Compared to shear numbers of 5.3L produced with "706" heads...Actual failures are rare.....

Some dimwit drilled to far to remove a broken manifold bolt...Is what happened.

Thanks for the input everyone.

I have my doubts that a "dimwit" drilled too far into the head. There were two broken manifold bolts that my buddy (bluex) did drill out, but they aren't the one's leaking. In both cases, neither bolt was drilled all the way through, so there's no chance he drilled too deep. And afterwards, we visually inspected each hole, and there was no visible damage.

I deal with porosity issues on a regular bases. My company represents about a dozen valve manufacturers, and I've seen casting issues in just about every material valves can be made from. I'm not 100%, but I'm pretty sure my heads are failing due to a porosity issue due to a flaw in the casting process.

Regardless, it would have been nice if you helped with my questions rather than pointed out that my evaluation was wrong. Your comments, while potentially educational, failed to help with my current issue or basis for my post.

Thanks to Br3w City & Outlaw Drifter for the helpful responses.

[clinebarger]

Originally Posted by MattPSU

Thanks for the input everyone.

I have my doubts that a "dimwit" drilled too far into the head. There were two broken manifold bolts that my buddy (bluex) did drill out, but they aren't the one's leaking. In both cases, neither bolt was drilled all the way through, so there's no chance he drilled too deep. And afterwards, we visually inspected each hole, and there was no visible damage.

I deal with porosity issues on a regular bases. My company represents about a dozen valve manufacturers, and I've seen casting issues in just about every material valves can be made from. I'm not 100%, but I'm pretty sure my heads are failing due to a porosity issue due to a flaw in the casting process.

Regardless, it would have been nice if you helped with my questions rather than pointed out that my evaluation was wrong. Your comments, while potentially educational, failed to help with my current issue or basis for my post.

Thanks to Br3w City & Outlaw Drifter for the helpful responses.

Sorry if I offended anyone, I am trying to help. And save you time & money.

[OutlawDrifter]

gm head bolts are fine and inexpensive, unless you intend on taking the heads on and off multiple times. then you should bite the bullet and use studs anyways.

i would use a replacement mls 5.3 gasket and call it a day.

[boostedc10]

Like Cline already said the 706 heads that have issues are a select batch of Castech heads and leak from the head bolt area.

I think you guys are taking the dimwit comment to heart, but more than likely "someone" maybe not you guys drilled too far. This happens all the time with these heads and isn't hard to do if you don't pay attention.

On to helping with a solution, either do what Cline said and throw some loctite on the bolts and let it dry or toss the heads and get another set. These heads are all over the place for next to nothing.

Not even worth the time discussing it much further.

[MattPSU]

Originally Posted by boostedc10

Like Cline already said the 706 heads that have issues are a select batch of Castech heads and leak from the head bolt area.

I think you guys are taking the dimwit comment to heart, but more than likely "someone" maybe not you guys drilled too far. This happens all the time with these heads and isn't hard to do if you don't pay attention.

On to helping with a solution, either do what Cline said and throw some loctite on the bolts and let it dry or toss the heads and get another set. These heads are all over the place for next to nothing.

Not even worth the time discussing it much further.

Again, regardless of the cause of the leak, my question related to a new set of heads that I already picked up. Therefore, the comments related to the cause of the leaks, suggestions for fixing the leaks, and name calling were all unnecessary. Even your last post, boosted, suggests that I do what I've already done.

And being that I took the new heads to the machine shop yesterday (after waiting a week for help from the forum), there's really no need to keep discussing the matter.

[clinebarger]

Originally Posted by MattPSU

Again, regardless of the cause of the leak, my question related to a new set of heads that I already picked up. Therefore, the comments related to the cause of the leaks, suggestions for fixing the leaks, and name calling were all unnecessary. Even your last post, boosted, suggests that I do what I've already done.

And being that I took the new heads to the machine shop yesterday (after waiting a week for help from the forum), there's really no need to keep discussing the matter.

Man, Your taking things WAY too personal, They are leaking out of holes your buddy didn't drill, Where did the Butt Hurtfullness come from?

You got this idea that "706" heads have issues from the internet, Then made up your own hypothesis that they will & can leak from the manifold bolts due to porosity....Good, It can still be fixed with Loctite.

[boostedc10]

Oh and to clear it up further here is the gm tsb for the issue http://ww2.justanswer.com/uploads/Bl...t_loss_5.3.pdf

[bluex]

What number loctitie are you guys referring to because the red I know of isnt a thread sealer and will only make future removal of the bolts even worse.

[boostedc10]

http://www.henkelna.com/product-sear...=8797876748289

[boostedc10]

What heads are at the machine shop? Also with the notch welded on the 862 you can run the LS9 gaskets. If it's not boosted you can also run the stock gaskets and be fine. That should answer your initial question. If it was me I would buy the stock ****, head gaskets and bolts.

As for why all the discussion about the leaking heads, 2 things. First was to make it clear for any future readers your leaking issue had nothing to do with the known Castech head problem, second was to give you an easy way to fix the heads you had that were leaking and for anyone else that may have drilled too far.

I think you guys took the name calling a little too personal, especially if you didn't even touch those holes lmao!