4Hummer

Need help with this one guys. so any input would help

Engine is a 22RE, I have an Exhaust mainifold leak AGAIN the last two bolts (Closest to the firewall) Are not tightening down. so I have an exhaust leak and the "tick tick tick" is back again

The holes had been helicoiled about 5 years ago, and stripped out about 6 months ago.. the leak came back.

The holes have now been tapped out to the biggest size possible 3/4 " I belive and larger bolts were put in. This held for a couple months and now the tick tick is back again.. and I cannot tighten those bolts any tighter (they just start to free spin).


So How do I fix this problem ? I cannot tap to any bigger of a size.

I was thinking I could maybe WELD a stud into the hole ? But I think that might warp the head. ???

than I was also wondering about this Stuff.

LINK: http://www.caswellplating.com/aids/faststeel.htm

Could I maybe fill the hole with this stuff than thread a stud into it and let it dry ? would it hold up to the heat ?

Any other Idea's Weld the mainifold to the head ? Use two gaskets and lots of RTV Sealent ? Duct tape ?

HELP GUYS PLEASE

4Hummer

Bump someones gotta Know.... Calling Mr. Brown ! Attn Roger Brown...

Just to Add:

The PO installed the Helicoils, I got my first leak about 1 year ago, replaced the gasket and thats when I noticed I couldn't tourqe the bolts down very tight, Few months later I removed the manifold again and discovered the helicoils, This time I decided to tap the holes to 3/4" But even than I STILL couldn't tighten those last three bolts very tight. I've re-torque them and I still cant get them super tight.

So the problem isn't that the bolts are working themselves loose, the problem is I cant tourqe them down tight enough.

Im pretty sure there isn't enough meat left for another set of helicoils to go in.

The manifold is straight BTW

what good products are out there that will withstand the heat ?

my thought is to replace these 3 bolts with studs, and somehow GLUE the studs into the Head. ???? Yes No ?


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94x4

Using a second nut on top of the first, to prevent it from backing off, comes to mind first;
Welding the studs comes to mind second, although you've expressed concern over warping;
Another possible option may be to cut the flange area between the individual exhaust runners to isolate them to help with expansion and contraction of the header, which could lead to manipulation of it's bolts/nuts.
Could'nt tell you anything about "gluing" some studs to the head, but might suggest a new head instead, as this would resolve all of the problem, period. Although there's no telling what the ever ingeniuos "Mr. Brown" may come up with.

rimpainter.com

Are you sure the manifold itself is not warped? Have you had it checked?

MTL_4runner

I was thinking the same thing...both should be checked and trued if needed.
If you already helicoiled several times, I would leave this repair to a machine shop (fill weld and retap) or find another head.

4Hummer

The manifold looked pretty straight when I half ass checked it. Ill double check it before doing any more work.

If been looking at this stuff http://www.belzona.com the Belzona 1111 Super Metal. it's $57.00 bucks a tube... The lady I talked to at head office says this will work, and the rest of the engine will fall apart before this stuff lets go ! She also deals with a 4x4 Group out in the city on Von Ontario that uses the stuff all the time. she says you can weld a cracked head back together with it. for a quick field repair, and also Re-mold broken axle teeth and all sorts of stuff.

The stuff is a workable putty. so the idea will be to smush the Belzona 1111 into the bolt holes, screw in the studs and let it dry. The stud SHOULD never let go again. than secure the manifold with some nuts and lock washers.

This is the best option Ive been able to come up with so far ? Unless someone else has an Idea ?

Check these out from http://www.belzonarockymountain.com/...20Polymers.htm

repair to a drive shaft


think its strong enough ???

rimpainter.com

Well I had the same problem on a 92 Maxima SE a while back. Turns out the stupid exhaust manifold was warped (it was impossible to eyeball). I had a guy at a machine shop check it with a special level, and he confirmed it was warped. The good news was that it was within the tolerences for machining, so he flattened it for me and it bolted right up.

MTL_4runner

Any machine shop should have a flat plate to check for warpage. Another trick is to use a piece of 1/4" glass as a homemade flat plate. If the parts are true, you shouldn't be able to get a sheet of paper in between them (knock down high spots with a file).

smiljko

I bought my truck with exactly same problem and exhaust gases warped my head.Exhaust manifold was warped also- you should check it and have it machined.My mechanic fixed it with helicoils and some welding- I will try to post some pics.