Dear rsparkerm,

Hope you're well. There are two 10mm and one 12mm bolts. The 10mm bolts go into the head. One is in the center of the case and the other is at the left-hand edge (as you face the engine). The 12mm bolt goes into the block, at the bottom of the upper section of the timing belt case.

Because the block is cast iron, it is unlikely that the threads in the block have been stripped: I can't recall a post, reporting that. It is more likely that the bolt threads stripped.

As noted, do not try to deepen these holes. I'd also be wary of trying to expand these holes, i.e., by using the next-larger-in-diameter bolt. I'd only do this if specifically told it can be done, by an automotive machine shop (engine re-builder). Engine re-builders know the details of oil and water passages in the block.

To avoid these risks, I suggested use of teflon tape, as a way to get the bolts to hold, if the threads in the head and/or block truly have been stripped. I've never had to do this, so am not sure teflon tape will hold.

If all else fails, and if teflon tape does not hold, then I'd clean-out the stripped hole. To remove any traces of grease or oil, I'd use methyl ethyl ketone (MEK), a highly inflammable and carcinogenic cousin of acetone. MEK will get the metal "surgically clean". Grease/oil keeps most things from bonding to the surface, on which the grease/oil is found.

Into the stripped hole, I'd install a stud of the correct diameter, securing it with a high temperature epoxy: JB weld might be suitable. With a washer and nut at the end of the stud, the timing belt cover will be secure. If you think you need to this, please post back: It is important that the stud not be too short, as once it has been epoxied, it will not come out.

Hope this helps.

Yours faithfully,

Spook