valve cover bolts/stripped threads in the head
Thread Starter
Senior Member
Joined: Jul 2012
Posts: 424
Likes: 13
From: Grand Rapids, MI
99 C43 AMG, 2001 CLK55 AMG
valve cover bolts/stripped threads in the head
hey all,
had a leak in the valve cover gaskets, replaced the gaskets and it slowly got worse. turns out it was because one of the bolt threads on the lower backside of the passenger side was stripped, so there wasnt proper pressure/torque specs in that area and it was leaking.
i have a buddy of mine coming to try and fix the issue this weekend with me. we were trying to find out what is the thread pitch of those bolts. does anyone know? might try to take a bolt to the parts store to find out but just checking to see if anyone here had experience with this issue? hoping to be able to re-thread the head - or use a helicoil.
any advice or things to look out for or try?
had a leak in the valve cover gaskets, replaced the gaskets and it slowly got worse. turns out it was because one of the bolt threads on the lower backside of the passenger side was stripped, so there wasnt proper pressure/torque specs in that area and it was leaking.
i have a buddy of mine coming to try and fix the issue this weekend with me. we were trying to find out what is the thread pitch of those bolts. does anyone know? might try to take a bolt to the parts store to find out but just checking to see if anyone here had experience with this issue? hoping to be able to re-thread the head - or use a helicoil.
any advice or things to look out for or try?
MBWorld Fanatic!
Joined: Mar 2010
Posts: 5,890
Likes: 323
From: Land of mountains, cheese, chocolate and watches
12' W204 C63 AMG coupe "T-Rex", 12' W451 Smart Fortwo Pulse (99' W202 C43 AMG + Ultima Can-Am sold)
Wow, bad luck. If the thread is totally stripped you need to fix with helicoil inserts.
Some reading: https://en.wikipedia.org/wiki/Threaded_insert
Regarding the bolt, I assume it must be a standard pitch in M size with Torx head if I'm not mistaken, but don't take my word for it. I'll do a quick check in the EPC and let you know in a moment....
Here are 2 files
Some reading: https://en.wikipedia.org/wiki/Threaded_insert
Regarding the bolt, I assume it must be a standard pitch in M size with Torx head if I'm not mistaken, but don't take my word for it. I'll do a quick check in the EPC and let you know in a moment....
Here are 2 files
Last edited by DRBC43AMG; Oct 18, 2016 at 12:58 PM. Reason: Added PDF files
Thread Starter
Senior Member
Joined: Jul 2012
Posts: 424
Likes: 13
From: Grand Rapids, MI
99 C43 AMG, 2001 CLK55 AMG
thanks for that info.
they are definitely torx head. and those quantities and size make sense to me, i took all the bolts out already for the right side, didnt check the left yet.
i dont know alot about stripped threads, but it seems like it would juuuuust about get to the torque needed per spec but then just goes loose again.
i know dont know much about pitch on bolts/threads, but my friend helping me just told me its something i should try to fond out before he comes over to help this weekend. a good parts store might have a template or whatever to check the pitch if i bring the bolt in?
thanks for checking EPC.
they are definitely torx head. and those quantities and size make sense to me, i took all the bolts out already for the right side, didnt check the left yet.
i dont know alot about stripped threads, but it seems like it would juuuuust about get to the torque needed per spec but then just goes loose again.
i know dont know much about pitch on bolts/threads, but my friend helping me just told me its something i should try to fond out before he comes over to help this weekend. a good parts store might have a template or whatever to check the pitch if i bring the bolt in?
thanks for checking EPC.
MBWorld Fanatic!
Joined: Mar 2005
Posts: 2,418
Likes: 194
From: America
1999 C43 AMG, 2005 E55 Wagon
this is why i'm terrified to do more work on my motors right now. with my old m104's, everything was solid steel and there was no amount of torque I could apply to strip things.
putting the water pump back on my old 4.3 motor I stripped a bolt using one hand on the ratchet!! that was a huge PITA to fix.
putting the water pump back on my old 4.3 motor I stripped a bolt using one hand on the ratchet!! that was a huge PITA to fix.
Thread Starter
Senior Member
Joined: Jul 2012
Posts: 424
Likes: 13
From: Grand Rapids, MI
99 C43 AMG, 2001 CLK55 AMG
As an update we did use a helicoil on the stripped threads, this was just before i put the car away for winter, but it looks like something is still wrong as oil seems to be slowly leaking out of the head gasket near that bolt...
i will try to wipe it all clean again and let it run to see if its new oil or old. im pretty sure we wiped any of the old leaked oil off the exhaust manifolds off last fall.
worse case scenario i take it to the shop and see what they say, they may be able to come up with a better or at least, better executed, fix than we did in the garage.
i will try to wipe it all clean again and let it run to see if its new oil or old. im pretty sure we wiped any of the old leaked oil off the exhaust manifolds off last fall.
worse case scenario i take it to the shop and see what they say, they may be able to come up with a better or at least, better executed, fix than we did in the garage.
