skene

So I just replaced my rod bearings, and had everything back together and started the car to see how things are going. The car was REALLY loud, so I poked around a bit and found that my #2 header is leaking at the head.

Apparently the PO had done something ugly to one of the studs there and decided to replace it with a bolt instead another stud. To make a long story short, the head is stripped there and the bolt just turns and turns and turns

What can I do about this? Do I have to pull the engine and thread in a bigger stud or bolt? Can I put another helicoil in without pulling the engine? How much would it cost me (mechanic $ or my hours) to fix this?

I'm pretty bumbed here since I'm taking off this weekend and was going to take my car, but now I'll be on the highways on my motorcycle instead.

skene

bump

Adam Roberts

I had a stud fall out of the #4 cylinder of my 86 N/A.. and the sound got ever lounder... sort of a 'tick-tick-tick" when I gave it gas.

the other stud came out .... and the gasket fell off.. and it was pretty loud.... I got a lot of looks and people wanting to race me at lights. Sounded pretty awesome...

flames shoot out at night too!

But did the guy strip the inside threading? I believe it goes into the engine block. If so, it looks like you're gonna have to re-thread the hole, maybe move up in size for the stud.

But I don't think you're going to have any short-term damage by driving it like that unless the header is COMPLETELY off.

For the short-term, see if you can lock-tite it in there and when the headers heat up, it'll seal it in there.

but that's what I would do.

Stan944

Before you start the repair, check if the bolt mounted by the PO was of the correct thread. Maybe he was an ignorant who put a smaller SAE size instead of a metric size. This is just a thought, but who knows?
Stan

Red 944

I wouldn't do what Adam did (letting it go, especially having the second one go) if you like your valves.
This happened to me too, I retapped it for a larger stud. Didn't have to take the header off, but it would be smarter to. If you don't just check and recheck that you're drilling and / or tapping straight in and not at an angle.

skene

So this is what's with this. Apparently the PO put a bolt in that was significantly shorter then it could have been, so it was barely biting at all. There was a helicoil or something like that in there, and half the threads were never touched on it. I'm going to get a bottoming tap, clean up the hole, and try to put a stud in with some locktite or possibly JB weld to keep it in place. I'm going to try to do this without taking apart too much of the car and see how it goes.
Thanks for the help guys, and if you've got any other suggestions, feel free to let me know.

seb928s

Yea don't let it get that bad like Adam did. Your backpressure will drop and you can damage those valves with not having the right amount of backpressure. Also not safe to have hot exhaust gases coming out right there where you have the fuel lines and if you have a even small leak that you can't even see just smell the fumes sometimes this can be really bad. Tap it with the next size up if you must. Hmm there was something else like JB weld but was a lot better with high temps I used it on my intake manifold.

Peckster

Will you guys stop thinking JB Weld will fix anything? The staff is crap.

83na944

Any chance that theres enough thread left to hold if you use a long enough bolt or stud? That'd get you on the road for the weekend.

seb928s

Peckster I said it was kinda like JB weld I know the actually JB weld is crap and didn't work so I got this stuff from a body/repair shop they said it works great and they don't have to weld sometimes if it's nothing to bad. I wish I knew what it was called but it's been on the intake manifold for the last year and a half now without any problems. I'll try to track down the stuff the guy said it's not sold to the public only some places actually sell it.

Danno

There's a putty stuff called "Liquid Steel" or some such thing. It comes on a strip of wax-paper that you tear off and knead the stuff like dough. It hardens to a really tough material that can be sanded, drilled and tapped like steel. Not sure how it would hold up to heat thogh. Used it to fix some ground-off corners on the side-case on my motorcycle (Honda probably didn't test how far you can lean those things over).

But more than likely, a long stud should fit into that hole just fine. Use the strongest Locitte you can fine and double-nut it to really install it tightly. The Toyota RAV-4 studs will also work and have a hex-hole on the end for an allen-key.

Tom M'Guinn

If I were stranded on an island and could only bring one general purpose expoxy material, it would be JB Weld. It will, in fact, fix anything. It says so right here:

http://www.jbweld.net/uses.html

skene

Thanks for the replies guys. I actually fixed my problem last week, but didn't quite get around to posting that. As it turns out the PO did an even crappier job replacing the stud then I thought, but that was to my advantage. He put a tiny bolt in, so it was gripping with maybe 1/4 an inch of threads. I ended up retaping the hole with a bottoming tap and just put a new stud in. There were enough threads left to make it rock solid, so it's all better now.

As for the JB weld, I know the stuff isn't as great as they advertise it to be. I was planning on using it just to solidify the hold if there weren't enough threads to be stronger and I had to pull half the car apart to tap it to a bigger size. As it was all I had to do was put a new stud in and lots of locktite.

The down side is that there's a tiny leak still, but I'm 90% sure that's from not replacing the gasket. The only reason I know it's there is because I saw a small puff of dust/smoke when the car first started up, then couldn't feel or hear anything unusual. I figure I can drive with it like that for a while at least.