How to thread strip Plenum bolt

[my1990300zx]

I have a 90 300zx NA and just got the plenum on and discover one bolt threads are strip in the very front,I was wondering how to fix this problem with out taking plenum off again do I rethread to next size for this bolt and tighten it or is there another solution and all the other bolts tighten work ok its the upper intake plenum manifold thanks , for your help

[NolimitZ32]

Depending on how badly the thread is eaten up you may be able to re-thread with the same size tap, if not then you will need to drill out one size bigger and thread it to a larger bolt. When attempting to re-thread be careful, go slow, use WD-40 or other lubricant and back out often. What you want to do is get it to bite about 1 full turn then back out and blow out the hole, then start again, this may take a little while but its the best chance you will have of salvaging the existing thread.

[supertopsecret]

Have you looked into a heli-coil? I've had good results with these. I haven't done it on a z but i have on several other cars.

[NolimitZ32]

Helicoil is a great alternative too, my brain is on weekend mode, I should've thought of that.

[my1990300zx]

Sounds like a great idea thank you

[DCaff300ZX]

You mention in your post that you want to do this without removing the plenum- regardless of the method you choose, the most important thing to consider is the bits and pieces from drill/tapping not getting into the engine.
I'll say off the top the BEST way to re-tap a thread is with the part off the engine to avoid contamination from metal bits, unless you can guarantee no entry of the bits into the engine cavity. Using a vacuum hose helps and would work for an external thread that does not penetrate into the airway, but it still is a good idea to remove the part for this work for best results and peace of mind.