Can you recompress an updated secondary chain tensioner?
Thread Starter
Newbie
Joined: Mar 2026
Posts: 13
Likes: 4
From: Annapolis/Ocean Pines MD
2012 ML350, 2010 Camaro 2SS, 1998 BMW M3 vert, 1985 BMW 5 Series with Procharged SBC
Can you recompress an updated secondary chain tensioner?
2012 ML350 with M276.9. Started with a cold start rattle. On teardown, found a bad Bank 1 intake phaser and lots of oil in the intake runners and lots of carbon on the backs of the intake valves. Plan expanded to new phaser, updated chain tensioners, install check valves, 4 cam solenoids, 4 cam position sensors, pigtails, new drip pan, new plugs, intake gaskets.
Replaced the phaser and my marks lined up, the reluctor marks lined up, but the laser mark on the replaced phaser was off by 2 teeth. Took the phaser off and sure enough, the laser mark on the FEBI phaser is TWO TEETH OFF from the OEM that failed. Not making me feel good about their quality control.
Went back to my marks and reinstalled the new phaser, but now I can't compress this brand new chain tensioner. Are the updated tensioners ratcheting? Can they be recompressed or are they one time use and I need to order another one?
Advice/experience appreciated.
Mariner1
Replaced the phaser and my marks lined up, the reluctor marks lined up, but the laser mark on the replaced phaser was off by 2 teeth. Took the phaser off and sure enough, the laser mark on the FEBI phaser is TWO TEETH OFF from the OEM that failed. Not making me feel good about their quality control.
Went back to my marks and reinstalled the new phaser, but now I can't compress this brand new chain tensioner. Are the updated tensioners ratcheting? Can they be recompressed or are they one time use and I need to order another one?
Advice/experience appreciated.
Mariner1
Last edited by Mariner1; Apr 15, 2026 at 04:40 PM.
Out Of Control!!
Joined: Apr 2019
Posts: 11,958
Likes: 6,802
From: Silicon Valley
W212 MY'14 M276-3.5NA @75kMi
repair almost complete
2012 ML350 with M276.9. Started with a cold start rattle. On teardown, found a bad Bank 1 intake phaser and lots of oil in the intake runners and lots of carbon on the backs of the intake valves. Plan expanded to new phaser, updated chain tensioners, install check valves, 4 cam solenoids, 4 cam position sensors, pigtails, new drip pan, new plugs, intake gaskets.
Replaced the phaser and my marks lined up, the reluctor marks lined up, but the laser mark on the replaced phaser was off by 2 teeth. Took the phaser off and sure enough, the laser mark on the FEBI phaser is TWO TEETH OFF from the OEM that failed. Not making me feel good about their quality control.
Went back to my marks and reinstalled the new phaser, but now I can't compress this brand new chain tensioner. Are the updated tensioners ratcheting? Can they be recompressed or are they one time use and I need to order another one?
Advice/experience appreciated.
Mariner1
Replaced the phaser and my marks lined up, the reluctor marks lined up, but the laser mark on the replaced phaser was off by 2 teeth. Took the phaser off and sure enough, the laser mark on the FEBI phaser is TWO TEETH OFF from the OEM that failed. Not making me feel good about their quality control.
Went back to my marks and reinstalled the new phaser, but now I can't compress this brand new chain tensioner. Are the updated tensioners ratcheting? Can they be recompressed or are they one time use and I need to order another one?
Advice/experience appreciated.
Mariner1
Let tensioner expend all the way out then press it back in with conviction.
The internal spring is low tension... manageable with one hand.
The backing surface has no gasket. Feel free to send the rough machined surface perfectly smooth to seal incoming oil pressure.
Your engine will soon run much better than for the past 30k.Mi. after ECU readapts over 500.
Mi.
Last edited by CaliBenzDriver; Apr 18, 2026 at 02:13 PM.
