The most likely thread stripping will be in the aluminum , not on the screw.
But if the alum hole is stripped , you may see alum on the screw threads

I can´t remember what the problem was, but I have had exactly the same experience (two spinning screws) and got it to work without anything but getting the pieces (cover and screws) in the right place...

__________________
-94 E 36 AMG Coupé, Brilliant Silver
-98 G 500, Obsidian Black
-05 Mini Cooper, Solid Black
-97 993 Carrera S, Ocean Blue

They all do it after time.
Its because it has been serviced previously by knuckleheads that run the screws in with air wratchets and just spin the threads off of the aluminum inside the cover.
The screw threads may be okay, but the threaded aluminum they screw into is no longer threaded.

It is not going to hurt anything by just leaving them in there or removing the ones that are stripped.

It would be senseless to take the cover off completely so dust stays away from everything.

Whoever said that you should use compressed air to remove debris from the spark plugs should be commended.

That should always be done before removing the spark plugs so the debris does not fall into the cyllinder head.


Just take the two bolts out and be done with it or leave them in there. It will
not be a big deal.

It seems as if just the top few threads in the 2 holes are missing as I can get any bolt to start in either hole without the cover in place. However, once the cover is on the 2 offending bolts cannot contact the threads and they spin freely. Oh well still have 4 with good grip.

My bet is you are missing the hole b/c the screw is slightly angled... if the threads were stripped on the top of the hole , you would se it ..specially when you tried the screws w/o the cover.

Arthur,
The thought of mis-alignment occurred to me; but I don't think this is the cause. The reason being that 4 of the bolts stand a bit proud of the cover when inserted and engage the threads within a turn or two. The other 2 bolts don't stand off at all and rest firmly on the bottom of the recess within the cover; without engaging any threads. it is as if the threaded hole is deeper, which would be the case if the top few threads are stripped.
regards,
Mark

BTDT. The threads are stripped. The stock bolts don't engage very far into the threads, so only the top portion of the threads are stripped. When you remove the cover and thread the bolts in, you are accessing the lower part of the threads, the unstripped portion.

I went to a good hardware store (Elliots in Dallas) and purchased bolts 5mm longer than stock. Had to use a washer or two to get a nice snug clamp on the cover, but it works like a charm. Cheaper and easier than six thread inserts. Just be careful not to bottom out the bolts.

- JimY

I have this problem with only one of the bolts on my cover, the one closest to the driver, up near the firewall. I just left it in place and not screwed in. It's a little frustrating to have everything in place except for this one bolt. Will be looking for your resolution. Thanks.

jcyuhn's solution seems right. I'll look for longer metric bolts (5mm is about 1/4 inch) when time permits.
regards to all,
Mark

jcyuhn is correct, at least in my case. Original bolts ar M6-1x70mm. Ordered 2 M6-1x75 bolts and 3 6mm washers from boltdepot.com for $9.7, of which $7.55 was the cost to ship by UPS Ground. These snugged up nicely with just 2 washers. I had driven for a few weeks without the 2 bolts in place without a problem, so the 'fix' was unnecessary; but I pleased.
regards,
Mark

Good to hear it worked for you. I think mine required two washers each as well.

Were you able to secure allen drive bolts like the originals? I had to use standard machine bolts, allen drive wasn't available in the correct size locally. Works fine, only the cogniscienti will ever notice. Only cost three or four bucks total to replace all six.

- JimY

Yes, boltdepot.com had the allen head cap screws.
mark

Only 3 of the 6 bolts will get tight. One of the bolts looks like it has the remnants of a helicoil or something of that nature. I've seen some comments that say the cover is not needed. I say bull to that. The cover serves as a direct hold down for the coils and a element cover. The rubber wires and boots wouldn't last very long subjected to dirt, road grime and moisture. I'm all for the helicoil method of securing. Without the bolts holding the coils down they seem loose.

Rick Potter

I just repaired mine a couple of weeks ago with Helicoils. One was stripped due to the dealer overtightening then some years ago. I ended up doing all 6 while I was at it.
I didn't feel confident drilling the holes by hand on the vehicle so I removed the valve cover and used a drill press. I measured the depth of each hole and where the thread started as each hole was different due to the shape of the cover. Drilled, tapped, installed Helicoils to measured depth and finished the job by getting rid of the rusty bolts and installing stainless allens.

You are indeed a perfectionist! I'll take your advice and give it try myself.