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2012 ML350, 2010 Camaro 2SS, 1998 BMW M3 vert, 1985 BMW 5 Series with Procharged SBC
Updated secondary timing chain tensioners on an early M276
Quick question. Advice I received on this forum says that you can (and should) install the updated chain tensioners on an early M276.
However, the parts manager for MB Classic claims you can't use a later tensioner on an early M276.
Can anyone confirm I can use the updated tensioners?
The TSB details 2013 M276 that need tensioners and check-valves. M276 tensioner rattling
After that 2013 date the ratcheting tensioners setup with check 2x valves received no further update.
However this setup is not always effective at preventing startup rattle regardless of all new parts.
Adding the necessary check-valves helped slow the oil bleed down. Tensioner has tiny air bleed ports
The TSB makes it sound like the original M276 pre 2013 was updated to the later common type.
We are now dealing with a ratcheting tensioner with integrated check-valve paired with a primary external check-valve.
It seems the second check-valve is installed to help prioritize the phaser pressure build-up over the tensioner...
Phaser sees: 0x check-valve
Tensio. sees : 2x check-valves Springs
The tensioner oil pressure reaches the same value but delayed over VVT.
Last edited by CaliBenzDriver; Mar 11, 2026 at 07:19 PM.
2012 ML350, 2010 Camaro 2SS, 1998 BMW M3 vert, 1985 BMW 5 Series with Procharged SBC
Oh boy, now I'm conflicted. Was the MBUSA parts manager right? Would I be better off installing a check valve and a fresh old stiyle tensioner that does not have an internal check valve? Or should I install a check valve and a fresh new style tensioner?
Would I be better off installing a check valve and a fresh old style tensioner that does not have an internal check valve?
Or
should I install a check valve and a fresh new style tensioner?
Mariner1.
Understand the quoted parts counter advice to not upgrade goes against the TSB.
A new tensioner is Very Welcomed to help steady the timing chain position with little tension.
The TSB busy work is supposed to "HELP" but is proven unable to effectively fix the low pressure rattling issue.
It's a step in the right direction
Ppl have replaced all new tensioners multiple times on stock setup for very short lasting improvement.
> Before / After :
Before TSB: more rattle
After TSB: less rattle <<<----
> Check-valve Helping /hurting ??
These low-tension secondary tensioner need all the air-free oil they can get to hold their ram.
I wonder if the best solution is to only replace new tensioner only - without adding external check-valve ??
Last edited by CaliBenzDriver; Mar 11, 2026 at 08:33 PM.
Quick question. Advice I received on this forum says that you can (and should) install the updated chain tensioners on an early M276.
However, the parts manager for MB Classic claims you can't use a later tensioner on an early M276.
Can anyone confirm I can use the updated tensioners?
" Remedy:
Replacement of secondary chain tensioners on left and right and installation of a check valve in the oil supply bore of
each secondary chain tensioner in the cylinder head on left and right.
Order the chain tensioners from the parts service according to the engine number as per EPC.
Order the check valves from the parts service after checking the diameter of the oil supply bore in cylinder heads."
Check the engine number as stated in the TSB, and decide if yours needs check valves, and chain tensioners. Buy according to EPC. You can use ( https://partsouq.com) , use YOUR VIN go to ENGINE MANAGEMENT/CHAIN DRIVE and see the current part number for YOUR engine.
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