Possible bent cam follower: Diagnosis help greatly appreciated!

[BACmotorsports]

My E90 M3 (2008, 94k miles) started making this noise:

[u2b]http://youtu.be/_QDGL_cL42M[/u2b]

The rhythmical nature of it, yet staggered every so many engine revolutions makes me think it is either a bad/bent cam follower or something with the timing chain/guides. Video is dark, but in any case, noise appears to be coming from the Bank 1 (passenger side) valve cover. Hopefully it is the top of the engine and not deeper! No fault codes, warning lights, oil reads in range. I do however think the power is down 30% or so, but with the noise I didn't drive it very far and didn't try any full out pulls or anything

I will be taking the valve cover off and posting back soon, but would love any advice, tips or other similar experiences/noises like you hear in the video. Also, I searched for valve cover (or related DIYs) but closest I could find was a throttle body replacement DIY (at least helps get through taking some of the top stuff of). If anyone knows of something better, please let me know. I could also buy TIS for a day if need be.

Thanks all!

Jeff

[BMRLVR]

Originally Posted by BACmotorsports

My E90 M3 (2008, 94k miles) started making this noise:

[u2b]http://youtu.be/_QDGL_cL42M[/u2b]

The rhythmical nature of it, yet staggered every so many engine revolutions makes me think it is either a bad/bent cam follower or something with the timing chain/guides. Video is dark, but in any case, noise appears to be coming from the Bank 1 (passenger side) valve cover. Hopefully it is the top of the engine and not deeper! No fault codes, warning lights, oil reads in range. I do however think the power is down 30% or so, but with the noise I didn't drive it very far and didn't try any full out pulls or anything

I will be taking the valve cover off and posting back soon, but would love any advice, tips or other similar experiences/noises like you hear in the video. Also, I searched for valve cover (or related DIYs) but closest I could find was a throttle body replacement DIY (at least helps get through taking some of the top stuff of). If anyone knows of something better, please let me know. I could also buy TIS for a day if need be.

Thanks all!

Jeff

I can't think how a cam follower could be bent but it is possible that you could have a sticking lifter. The S65 runs hydraulic lifters and by their design and how they fit in the lifter bore, if one were bent/damaged it is most likely that it would want to seize in the bore and your problems would be much greater than just a noise.

[Devant]

Originally Posted by BMRLVR

I can't think how a cam follower could be bent but it is possible that you could have a sticking lifter. The S65 runs hydraulic lifters and by their design and how they fit in the lifter bore, if one were bent/damaged it is most likely that it would want to seize in the bore and your problems would be much greater than just a noise.

I thought the same thing, AFAIK the only thing to generally go wrong with a cam are wiped lobes, which result due to lubrication or timing issues.

[BACmotorsports]

Thanks guys, what are your theories then? Not the greatest data to work with (the mostly dark video), but would love your best guess, thanks,
Jeff

[BMRLVR]

Originally Posted by BACmotorsports

Thanks guys, what are your theories then? Not the greatest data to work with (the mostly dark video), but would love your best guess, thanks,
Jeff

Copied from my first reply: I can't think how a cam follower could be bent but it is possible that you could have a sticking lifter. The S65 runs hydraulic lifters and by their design and how they fit in the lifter bore, if one were bent/damaged it is most likely that it would want to seize in the bore and your problems would be much greater than just a noise.

[BACmotorsports]

Thanks. Is the sticking lifter problem similar to that with the S54 engine? Looks like a potential fix for that was warming the engine and then holding rpm at 3-4k for a few minutes. That may have been to purge air, but perhaps that's the issue here.

[thekurgan]

Originally Posted by BACmotorsports

Thanks. Is the sticking lifter problem similar to that with the S54 engine? Looks like a potential fix for that was warming the engine and then holding rpm at 3-4k for a few minutes. That may have been to purge air, but perhaps that's the issue here.

S54 has no hydraulic lifters, so no, you mean the N54/N55.

[BMRLVR]

Originally Posted by thekurgan

S54 has no hydraulic lifters, so no, you mean the N54/N55.

+1 No Hyd lifters in S54.

[SilentAttack]

doesn sound so hot.