[Mr. Shadow]

Originally Posted by excessive

That is correct, the exhaust bolts had no wear on them, only the intake ones were loose. As for the intake cam bolts, they were all loose, some of them had worse wear than others, but all had wear marks. One was almost 50% worn through.

That's really scary

[Krehtan]

Is there any chance you could post a sound clip of your engine now that you've done the repair work?

[excessive]

Originally Posted by Krehtan

Is there any chance you could post a sound clip of your engine now that you've done the repair work?

any particular reason why? it sounds like a smooth running S54.
I dont' have any sound clips before I did the repair, I guess i should have gotten one.

[kaiv]

Excessive, thanks again for all the research you have done and for posting the findings in such a detailed manner

I have seen pictures on this very forum of vanos/cam gears/sprockets and what not shooting through the valve cover and have been wondering how and why such failure can occur. As far as I'm concerned this issue has sort of been a mistery until now. So thank you for sharing all this precious information with the community!

My 02/01 M3 has 127k miles and although it doesn't make any unusual noises it sees a lot of track time and I've been worried about this too.

Luckily I checked everything today and everything is 100% tight.

If anyone is interested I have a set of 12 new OEM bolts and 1 new OEM vanos gasket available FS.

[excessive]

Originally Posted by kaiv

Excessive, thanks again for all the research you have done and for posting the findings in such a detailed manner

I have seen pictures on this very forum of vanos/cam gears/sprockets and what not shooting through the valve cover and have been wondering how and why such failure can occur. As far as I'm concerned this issue has sort of been a mistery until now. So thank you for sharing all this precious information with the community!

My 02/01 M3 has 127k miles and although it doesn't make any unusual noises it sees a lot of track time and I've been worried about this too.

Luckily I checked everything today and everything is 100% tight.

If anyone is interested I have a set of 12 new OEM bolts and 1 new OEM vanos gasket available FS.

You're welcome. And as I've stated several times, 2001-2002 M3's don't seem to suffer from this problem!!!!

[F85W31]

Excessive, thank you for the sharing of information through your great writeup. Has the potential for bottom end problems been mentioned by the master tech? All those metal shards represent contamination well beyond normal wear and will be distributed though the lubrication system despite the oil filter. Based on your photos, the fasteners are literally ground down to fine particles. Main bearings and possibly cam bearings come to mind...

[maveric23]

OP, how did you ensure that there was no amount of oil in the cam gear bolt holes when you installed the new bolts?

I assume that any oil in these holes could be a big problem...

[kuksul08]

Excellent DIY. I will surely wiggle my cam gear next time I do the valve adjustment.

I would probably spray some brake/contact cleaner in those threads and use a bunch of red loctite to ensure they never come out!

[excessive]

Originally Posted by F85W31

Excessive, thank you for the sharing of information through your great writeup. Has the potential for bottom end problems been mentioned by the master tech? All those metal shards represent contamination well beyond normal wear and will be distributed though the lubrication system despite the oil filter. Based on your photos, the fasteners are literally ground down to fine particles. Main bearings and possibly cam bearings come to mind...

You have a good point, that metal had to go somewhere - but there's really nothing I can do about that now. The engine runs great, so I guess I will just keep hoping that it stays that way for a while longer! THANKS AGAIN BMW!!!

Originally Posted by maveric

OP, how did you ensure that there was no amount of oil in the cam gear bolt holes when you installed the new bolts?

I assume that any oil in these holes could be a big problem...

I did try to sort of wipe out the bolt holes with a Qtip, but there really wasn't much oil in the holes. I guess I probably should have mentioned that in the DIY, but I really believe that the real reason they come loose is that they are not the right hardness. I don't think it has much to do with the loc-tite at all, but it surely can't hurt.

[jones]

Originally Posted by maveric23

OP, how did you ensure that there was no amount of oil in the cam gear bolt holes when you installed the new bolts?

I assume that any oil in these holes could be a big problem...

In my experience (limited though it is) oil between the bolt and the hole doesn't matter if you're using loc-tite. In fact, it's usually good to have some in there.

Granted, I've never replaced the VANOS bolts. I'm talking mostly about main bearing bolts and such on other engines.