considering your apprehension....

I suggest the JB weld or similar epoxy. Search around for something stronger, perhaps.

If you can still thread the bolt in there and it holds torque (just not 100nm) it may be a worthwhile option until you are ready to put the car down and tear into it.

I still believe in doing a timesert in the engine bay. Use your creativity....



There are guides that would help you establish the right angle and keep the bit straight. Plus, the existing bore will do most of the guidance, regardless.

After that, tapping aluminum is pretty easy.