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Discussion Starter #1
Hello guys, this is my first post, I'm Daniel, from Brazil, I have a mechanic shop here and one of my clients brought an M5 with rattling noise.
After some research I decided to remove both chain tensioners for inspection and both seemed to have low oil pressure on them, the right side one had a little more pressure (and engine rattled more on left side).
I ordered new tensioners and my real question here is. can I just screw them on and star the engine? or do I need to turn engine mannualy, check timing or something else.

Learned a lot about these cars here but couldn't find any info on this.

Thanks a lot

Daniel
 

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Hello guys, this is my first post, I'm Daniel, from Brazil, I have a mechanic shop here and one of my clients brought an M5 with rattling noise.
After some research I decided to remove both chain tensioners for inspection and both seemed to have low oil pressure on them, the right side one had a little more pressure (and engine rattled more on left side).
I ordered new tensioners and my real question here is. can I just screw them on and star the engine? or do I need to turn engine mannualy, check timing or something else.

Learned a lot about these cars here but couldn't find any info on this.

Thanks a lot

Daniel
If you're talking about the timing chain tensioners, you can just replace them, but rarely do these fail on the S85 and cause rattle. Normally the rattle is in the VANOS cam drive gears as a result of low VANOS pressure or air trapped in the system.
 

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Discussion Starter #3
I see, but since it was easy to remove the left side one I gave it a shot, I don't know about these engines, but it really felt like a failed part compared to others I'm used to.. so I went on and removed the second one and confirmed more pressure (less noise) on right side..
Car was not used for more than 2 years so I figured it could be the reason for failure on tensioners.

and it would be much easier to remove them than test VANOS pressure.. don't have many specific tools available for that in Brazil and dealers and indys are not used to lend theirs =/

also, VANOS readings on scanner were OK (angles and valves)
 

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Discussion Starter #4
If you're talking about the timing chain tensioners, you can just replace them, but rarely do these fail on the S85 and cause rattle. Normally the rattle is in the VANOS cam drive gears as a result of low VANOS pressure or air trapped in the system.
If rattle continues, how can I bleed VANOS oil line to try to remove air in the system?
 

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To bleed vanos you need software ISTA or DIS you can download it online if you search or simply buy cheap on ebay they will also provide Instalation instructions.
 

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If bleeding will not help get rid of this rattle next step would be checking vanos pressure , you can make build this gauge yourself. You will need hydraulic gauge up to 2000 psi on ebay this cost around £10 , hydraulic hose you can build and buy for around £20 just google it and double bunjo hollow bolt( make sure it can handle big pressure around 100 bar). Then check pressure I believe at idle no less that 70 bar but please do research. IMG_7878.JPG IMG_7880.JPG IMG_7886.JPG
 

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Discussion Starter #7
Right, Thanks, I'm expecting tensioners to arrive between today and tomorrow.. hopefully it solves it.. if not I'll try VANOS, I have gauge like that, just need new tip with bolt! =]
 
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