Valve cover stud won't tighten

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guidonhue
Posts: 6
Joined: Tue Jan 04, 2022 3:40 pm
Location: El Segundo CA

Valve cover stud won't tighten

Post by guidonhue »

Hey all -

I replaced my valve cover gasket, and all but one fastener is tightening. The rear passenger side (bottom left of the valve cover) stud is spinning in the head and I can't get it to tighten against the nut on the valve cover. It also has some wiggle/play when I move it by hand. Would blue/red Loctite do the trick or am I in for much more than that?

Thanks
1979 BMW 528i 4-speed manual
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Mike W.
Posts: 2653
Joined: Wed Aug 30, 2006 12:12 am
Location: Sonoma County

Re: Valve cover stud won't tighten

Post by Mike W. »

Thread locker won't work. Locktite does have a product for this, Stripped thread repair. That might be worth a try before getting a helicoil kit.

Threading and rethreading into aluminum isn't great, especially the 6MM bolts which are fine threaded, not that you had a choice in the matter, and curiously E3s before E12 and E28s after used studs, not bolts for the valve cover.

https://www.summitracing.com/parts/lct-28654
Mike W.



1980 528i, 3.5 euro, 5 speed conversion
1981 528i, 3.6, Recaros and more. Project
1998 328is, quick and efficient, but not satisfying
2000 528iit, Vacation mobile/wife's grocery getter
canada karl
Posts: 965
Joined: Tue Jan 06, 2009 3:50 pm

Re: Valve cover stud won't tighten

Post by canada karl »

JB Weld has a similar epoxy thread kit that might not be as expensive. It worked well on a small stripped bolt hole on a brake caliper on my TR3. the kit should be an OK repair for a valve cover but I would not use it on a critical bolt.
1976 530i. BMW 59 Triumph TR3A(rolling resto). 67 Triumph TR4A(salvageable). 86 900S Winter car
guidonhue
Posts: 6
Joined: Tue Jan 04, 2022 3:40 pm
Location: El Segundo CA

Re: Valve cover stud won't tighten

Post by guidonhue »

Well I fixed it!

Long story short, previous owner striped insert out of aluminum head, and either 1) exposed crappy M8 x 1.25 threads or 2) tapped his own, then used a custom M8 to M6 stud to clamp on. Near solution, but not long lasting! The M8 threads were also stripped to hell, I could only grab one or two threads that ended up stripping when I tried to go hand tight. A drill + tap to M10 x 1.25 and a key insert later we’re back to an M6 hole that can actually hold some torque.
1979 BMW 528i 4-speed manual
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