'87 260e Camshaft Cap Bolts Stripped - PeachParts Mercedes-Benz Forum

kevindn · #1 11-25-2006, 07:58 AM

I have a 1987 260E showing 152000 miles, I discovered testerday that I have 4 stripped cap bolts. I understand it is possible to heli-coil the threads and replace bolts. Is it this easy? If I were to do this, what size drill bit, heli-coil, depth of bit, where to find new cap bolts??? Or anything else Ineed to know would be helpful... thanks kevin

david s poole · #2 11-25-2006, 11:02 AM

take one of your bolts to where you will buy the helicoil set[you get drill bit ,tap and insert tool]you will need to buy some helicoils the same depth as the stripped holes.fairly easy job make sure that you clean up the trash after each hole.

Strife · #3 11-25-2006, 01:31 PM

What were the circumstances in getting them stripped. Did you torque them right and they stripped anyway?

kevindn · #4 11-25-2006, 01:53 PM

No actually it was running when I started to hear ticking, then clinging, then clanging... After doing some reading it is not uncommon in these 103 engines for the cap bolts to become loose or strip threads after 125-150 thousand miles. I just didn't catch mine in time... Im still a little unsure of drilling my head. And also not sure if I could get the right size, material, and proper usage heli-coil from my local auto parts store??? Any refrences would be helpful. thanks kevin

waybomb · #5 11-25-2006, 02:33 PM

These are metric threads. Just go to the next size diameter bolt with the same pitch thread as the originals. Shouldn't need helicoils with metric threads.

However, if you insist on thread inserts, use keenserts, not the cheap helicoils.

Gilly · #6 11-25-2006, 04:00 PM

Don't know WHO thought that one up, about the bolts loosening up or "stripping " all by themselves. Probably some inventive mechanic who messed up a job and told that to a customer to cover his butt. No way, never seen this. The cam is pretty hard stuff, course those bolts are too, but would hold out hope that new bolts, which I'd get from a dealer or MB parts specialist like this site, will fix it. I agree with Waybomb though, I wouldn't trust any of the repair inserts in this particular position, there just isn't enough depth of material in the front flange of the camshaft to use these, and it's too critical of an area. I'd go oversized, not repair insert. And if you go oversize, get the toughest bolts you can. Any doubt if it was a good repair or not I'd get another camshaft.
Gilly