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Been a while guys since I sold my 2012 s550 M278 but I'm looking at buying a 2008 Mercedes S-Class s63 AMG and have a quick question please. If I remember correctly, the M278 engines were prone to connecting rods being manufactured in a "bent" fashion creating cylinder distortion over time and was wondering if the M156 engines suffer the same fate? Other than the OEM headbolts being trash and needing to be replaced with ARP hardware, any other mechanical issues that the M156 engines may be plagued with? Thanks in advance!!!
Here's a pic of the s63 beauty 2009 s63 AMG
Last edited by Ultrakla$$ic; Apr 7, 2025 at 07:50 AM.
Nice car! I searched and searched and could not find a nice one when I was looking. There are no lower end issues with the M156 I am aware of. The problems are on the top side of the motor like head bolts and premature cam/tappet/lifter wear. Its a car that needs regular oil changes with top quality juice and even then you may still have to refresh the top end at some point. Wouldn't hold me back though as that is cheaper than having to re-sleeve an M278/M57 or buy a whole new motor once the cylinder bores wear out.
Make sure you get it thoroughly checked out. I cringe when I see a ~$150k car like that in a dirt lot along with lots of other ~$10k cars. No telling how much deferred maintenance is hiding there waiting to bite you. Parts will be $$$ and some may be getting hard to find now.
Good luck and do come back and post if you end up getting it. Very psyched for you!
Last edited by TripleDown; Apr 7, 2025 at 11:00 AM.
Nice car! I searched and searched and could not find a nice one when I was looking. There are no lower end issues with the M156 I am aware of. The problems are on the top side of the motor like head bolts and premature cam/tappet/lifter wear. Its a car that needs regular oil changes with top quality juice and even then you may still have to refresh the top end at some point. Wouldn't hold me back though as that is cheaper than having to re-sleeve an M278/M57 or buy a whole new motor once the cylinder bores wear out.
Make sure you get it thoroughly checked out. I cringe when I see a ~$150k car like that in a dirt lot along with lots of other ~$10k cars. No telling how much deferred maintenance is hiding there waiting to bite you. Parts will be $$$ and some may be getting hard to find now.
Good luck and do come back and post if you end up getting it. Very psyched for you!
Thanks for the reply! Yea, I am VERY familiar with the "Overengineered European Parts Tax"...........LOL. I loved my s550 and it was a LOADED optioned car, but I was weary of that cost factor so I bailed and sold it, HOWEVER, nothing rides/drives even remotely close to my exlove s550 so I'm back looking for another. I've watched alot of videos regarding changing the head bolts and although I can/would do the job myself, a broken head bolt inside the block is not something I'd want to try to fix IF it did happen. If all the OEM head bolts would come out without breaking the heads off, I'd be happy as a pig in slop though. I'd put the VRP billet cam phaser plates in the car too
Last edited by Ultrakla$$ic; Apr 7, 2025 at 01:51 PM.
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so I'm back looking for another.
I've watched alot of videos regarding changing the head bolts and although I can/would do the job myself, a broken head bolt inside the block is not something I'd want to try to fix IF it did happen. If all the OEM head bolts would come out without breaking the heads off, I'd be happy as a pig in slop though. I'd put the VRP billet cam phaser plates in the car too
