Retorque head bolts - two questions

Hey guys, two questions about head gaskets.

I have had a slow coolant leak for years. Thought it was this or that, finally got dye and it's coming out the back side of both heads. Again, slow leak, but I have to add half a gallon of water/coolant every 4-500 miles.
Would re-torquing the head bolts help this? Hurt it?

Also, I've been turbo'd for a couple years now and I was thinking of re-torqueing the head bolts to be safe(er) anyways. Thoughts? I've read the way to do it is to back ONE bolt off 90°, then re-torque to stock spec. And follow the standard torque sequence start to finish.

Thanks,
Joshua

I don't think that retorquing the head bolts would help with this problem. Is this the "basically healthy" engine that you want to change the cam in without pulling it out? Leaking head gaskets doesn't sound very healthy to me. It sounds like you need to change head gaskets and this would be a good time to pull it out and also change cams. Another thing is that you didn't say whether this is a 6.9 or 7.3. If it's a 6.9, I'd say that it's time for head studs too.

Yeah same engine, sorry I forgot I didn't have a signature.

7.3l 4x4 Stock turbo with 3" outlet mod and 3" down pipe, IP rebuilt by Russ(maxed out), with new old stock stanadyne injectors around the same time.

While I don't disagree that leaking headgaskets aren't good, this issue has not changed in years and over 80k, probably since I've owned it over 100k. Same slow leak, would never have found it without dye. No coolant in oil or oil in coolant, starts well and drives well, up to 15 psi loaded stock turbo that I've had now for 2 years or so.
That's why I said it's basically healthy...plus rumor has it leaking from the rear of the heads is quite common on these engines.

Don't get me wrong...I'd be stoked to have a fresh engine built right with the cam and better rings and get 19mpgs at 75mph like some of you guys!

I don't think that leaking head gaskets is real common with out a reason for it to happen in the first place. An example would be overheating the engine and slightly lifting the heads which also slightly stretches the head bolts. I'm not saying that you did this, but I'd bet that someone did. Especially with both head gaskets leaking. I still don't think that trying to retorque the head bolts will stop the leaking once it's started. Another thing to consider is that after driving it for two plus years with seeping head gaskets, there could be an extremely small groove worn into the gasket sealing material itself by the escaping coolant. The best that you could hope for in this case is a Band-Aid fix even if it does stop the leak. If you do try to retorque the bolts, I don't see any need to back them off the 90*. I'd just move them far enough to break them loose. This way, you won't be completely releasing the torque that's already on them. You don't torque just one at a time when installing them, so why would you want to completely release one and then torque it down again?

I had an odd coolant leak once, although our manifolds are dry the heads have passages for use in some application with a wet manifold. It may be possible your leak is actually at the intake but runs to the back of the engine.

That said, I've thought more than once about changing to studs on my 6.9 in the way you describe. Looks like I'd have to pull the brake master cylinder and the heater box (and the turbo of course). Is this idea crazy?

Thanks,
- Jeff

batchman said:

I had an odd coolant leak once, although our manifolds are dry the heads have passages for use in some application with a wet manifold. It may be possible your leak is actually at the intake but runs to the back of the engine.

Thanks,
- Jeff

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That's an excellent suggestion, I'll have to look at that closer for sure, hard to get back there on the pickup!

batchman said:

That said, I've thought more than once about changing to studs on my 6.9 in the way you describe. Looks like I'd have to pull the brake master cylinder and the heater box (and the turbo of course). Is this idea crazy?

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It's really not a good idea. For one thing, you'd still be running the same old head gaskets. Another thing is that you need to clean all of the built up crap out of the head bolt holes. It's absolutely amazing how much is actually in there. If you don't clean the holes out, the your studs won't go all the way to the bottoms of the holes. You'll be grabbing ahold of fewer threads and therefore you'll also be cancelling out any gained strength. If you have a worst case senario and pull the threads out of your bolt holes because your studs couldn't grab enough threads, then it won't matter whether or not your studs are stronger than head bolts.

Dont retorque, you will impart new loads on an already failing gasket. 6.9 I assume?

The OP has a 7.3. Batchman, who talking about replacing bolts with studs one at a time, has a 6.9.

IDIBRONCO said:

The OP has a 7.3. Batchman, who talking about replacing bolts with studs one at a time, has a 6.9.

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Yep!

For Josh, I'd guess since you have to take the manifold off to do head gaskets, you may find evidence enough of your leak to stop at that step...

For my crazy one-stud-at-a-time idea, it's the only way studs would/could happen here, and I don't appear to have any head-gasket problems (yet!). Had not thought about how to go about chasing crap out of the threads out though - thanks for the tip.

Thanks,
- Jeff

I wouldn't be worried about not being able to clean the bottom of the hole. You can figure out how to make an adapter for compressed air (or a long thin-nosed blow gun). Carb cleaner or other solvent already has the little red plastic tube taped to the side of the can And I'll bet an extension could be made to lengthen a thread chaser tap, also.

But in reading up on this, several people have expressed concerns that having one bolt completely untorqued with the others at full tightness might warp or crack the heads. I don't know how valid that is, since there are 17 bolts and the remaining 16 should hold a cold, non-running head pretty flat.

I recently had rebuilt heads with stock bolts installed on my 7.3 since it was leaking coolant to the outside from both head gaskets. Obviously got new gaskets too. So I wouldn't want to have to drain the coolant, remove all the bolts and retorque them all on a now-used gasket.

Has anyone actually done the one-at-a-time approach? Was there any ?

DrCharles said:

But in reading up on this, several people have expressed concerns that having one bolt completely untorqued with the others at full tightness might warp or crack the heads. I don't know how valid that is, since there are 17 bolts and the remaining 16 should hold a cold, non-running head pretty flat.

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That's what I keep thinking... On a cold engine I just don't see a stress riser to worry about. I believe I will come to a point where I need to try it or go PSD, and I really don't want to go PSD if I can help it .

I dunno, my ideas get pretty far fetched sometimes but this just doesn't look bad to me...
- Jeff

If there’s contamination in the bottom of the hole, which there always is, you run a good chance of breaking the block there.

@IDIoit had this happen to with his stud girdle where is it basically exploded the block around the main cap bosses because there was some amount of contamination still in the hole, even after he cleaned and prepped he threads thoroughly. It’s not impossible to do it one bolt at a time, but the only time I’ve seen people do it successfully was on a newer Cummins engine with an mls gasket.

i cleaned the **** out of those holes too.
but i think the real problem is that when i torqued the nut, the stud turned with it.

always go bottom out by hand, then back it off 1/4 turn.
block comes back from the shop with a balanced rotating assembly hopefully, this week.
i will try again!