M42 valve cover bolts

[lolcantturn]

I took off my valve cover, when I tried putting it back on almost none of the bolts seem to get tight at all. Is this common? What should I do?

[Anthony B]

Helicoils on the head, it's not uncommon when over tightened that the threads on the head are damaged my m40 has similar problems & my m42 has two threads on the head with helicoils in it

[lolcantturn]

and it's not like this is my first time wrenching, I know how to take off and put a bolt on thank god. Just very weird. It's not leaking but I don't feel confident in it

[salvuhdor]

These bolts take about 8lbs of torque. If too tight you have lost the thread. Time to learn how to helicoil

[vpilarrt]

The M42 valvecover bolts are designed to tighten fully against the head. The protrusion is sized to apply the correct amount of squeeze on the valvecover gasket. So if they keep spinning the female threads in the head are stripped.

[lolcantturn]

Fair enough. I bought new bolts that are about 3 threads longer than the old bolts, fitted it with the rubber boots and spacers and they seem to have done the trick.

[roguetoaster]

Fair enough. I bought new bolts that are about 3 threads longer than the old bolts, fitted it with the rubber boots and spacers and they seem to have done the trick.

Seems like a good solution vs a Helicoil. I am assuming you used a straight through bolt rather than the stock double shouldered?

[bmwman91]

The threads in the head will ALL die eventually. Constant thermal expansion/contraction cycling will ensure that as the aluminum and steel parts expand different amounts. The rubber bushings are supposed to help, but they don't.

I had to helicoil every damn one.

http://bmw.e30tuner.com/articles_vchc.php

[lolcantturn]

Seems like a good solution vs a Helicoil. I am assuming you used a straight through bolt rather than the stock double shouldered?

standard straight through bolt.

[M-technik-3]

The threads in the head will ALL die eventually. Constant thermal expansion/contraction cycling will ensure that as the aluminum and steel parts expand different amounts. The rubber bushings are supposed to help, but they don't.

I had to helicoil every damn one.
http://bmw.e30tuner.com/articles_vchc.php

great write up

[Threehz]

Seriously good write-up. When I did the valve cover I found a couple of mine to be stripped, will definitely be referring to this at some point.

[Nick_S]

Just had to helicoil every freakin one also. About $40 in parts and 2 hours time if you're moving slow and you'll be set. Used that write up as a reference because I've never done it, was painlessly easy.

[kwill22]

The longer bolt solution will only work for so long. Dependent on how manny times you take your cover off. I did that as a quick fix to mine and the holes eventually wore out again. And I got tired of adding spacers and trying to get very hole perfect.

I eventually just got some threaded inserts from grainger and did all of my holes except for the 2 that weren't damaged.

[Dj Buttchug]

the best way to fix this problem is convert to valve cover studs. run 8x1.25 studs with washers and 10mm nuts. all the stuff can be found at ace hardware.

[Bimmian89]

Use time certs. 1000X better than helicoils.