Valve bolt hole stripped?

[bushkanaka86]

I am in the middle of doing a valve cover replacement as I type this and everything has been going smooth except when I tried to tighten bolt number 7 (upper right corner), it won't tighten. I didn't over tighten it as it never got tight in the first place. I tried switching bolts and it does the same thing. The bolt I took out of the hole seemed to be tight when I removed it.

Do I have to do some sort of helicoil repair? Gonna add a lot of time to my repair job...

[billr]

A coil insert is probably going to be the most reliable, and easier than trying to find/make a special screw with over-size threads. I'm sure some folks will claim success with an epoxy like JB Weld, but I wouldn't even bother. Isn't that stripped hole pretty accessible? Other than keeping chips out of the head, I would think it would actually be very easy to put a coil insert in there...

[bushkanaka86]

No, it is the hardest one to get to back by the oil cap. Do you happen to know what diameter insert I would need for a 97 SL2?

[OldNuc]

They are 6mm X 1.0 mm pitch and you can buy the helicoil kit at the local part store. If the threads have actually pulled out of the head you do not have to and do not want drill out the hole before tapping for the helicoil. If you have never done this before you want to first buy the kit, read the instructions and then remove the cam cover. Following that come back here and let someone who has done several of these explain how to do this correctly the first time.

[billr]

"No, it is the hardest one to get to back by the oil cap."

I'm assuming this repair would only be attempted with the valve cover off of the engine...

[OldNuc]

It is near impossible to do with the cover on and can be difficult with it off as there is minimal maneuvering room back there. The taping is touchy to do at best. You may end up buying some unusual tools to do it right.

[bushkanaka86]

I went with the cheap option and used a 1/4-20, 1 1/4 inch long bolt. It fits perfectly into the hole without drilling anything. For the holes around the edge, it doesn't matter. However, one of the bolts in the center also threaded while I was putting it in. I was very careful to tighten the right amount but it still threaded out.



You can see the left bolt of the 3 in the middle. It went in just fine but it doesn't quite seal the whole like the original bolts. While the bolts around the edge don't matter if they seal, this one does. I currently have the original washer and a 2nd smaller washer in place right now but oil still leaks out slowly. Any thought on how I can seal this without drilling the hole?

[billr]

Clean the screw and washer and then soft-solder them together. Or, use some RTV between the screw head and washer.