M278 Timing
Thread Starter
Newbie
Joined: May 2026
Posts: 9
Likes: 1
2014 MB GL450, 2011 BMW 135i, 2024 GMC Terrain
M278 Timing
Does anyone have a timing procedure for the M278. I'm putting the Bank 1 side back together after my pulse ring shifted and cam adjustor went out. I only have the passenger side valve cover removed and am wondering if someone has done this before that can shed some light on the procedure.
I have the cam shaft hold down tool, a cam adjustor locking tool as well as the pulse ring alignment tool. Engine is at 40* TDC for cyl. 1, I have the laser engraved lines on the back of the pulse ring, but when I install the pulse ring alignment tool they don't match. What I mean by that is that when the line on the pulse ring is level with the top of the head, the pulse ring alignment tool does not sit flush on the head. Am I going crazy or missing something here? I'm attempting to do this without removing the valve cover on the drivers side. Any insight would be greatly appreciated.
Additionally, I have two yellow marks on my timing chain. One mark is sitting on the intake camshaft, the other is beneath the head towards the crank shaft. Do I need to align those with the marks on the cam adjustor teeth or does it not make a difference. I'm going crazy just staring at this in my engine bay.
HELP! lol
I have the cam shaft hold down tool, a cam adjustor locking tool as well as the pulse ring alignment tool. Engine is at 40* TDC for cyl. 1, I have the laser engraved lines on the back of the pulse ring, but when I install the pulse ring alignment tool they don't match. What I mean by that is that when the line on the pulse ring is level with the top of the head, the pulse ring alignment tool does not sit flush on the head. Am I going crazy or missing something here? I'm attempting to do this without removing the valve cover on the drivers side. Any insight would be greatly appreciated.
Additionally, I have two yellow marks on my timing chain. One mark is sitting on the intake camshaft, the other is beneath the head towards the crank shaft. Do I need to align those with the marks on the cam adjustor teeth or does it not make a difference. I'm going crazy just staring at this in my engine bay.
HELP! lol
