Chain chatter/rattle STILL.....

[Jtuner]

SO,, when I got my m42, it had a horrible rapping/chatter/rattle.. I searched the forums, read up a little bit and figured out it was my timing chain tensioner.. I order the tensioner and r&r it.. the rapping sound went away, but chatter/rattle still existed from 2k-3.2k... I was then told it was my chain guide rails.. SO about 6 months later i finally get to change them, which brings us to yesterday...  I got everything done, rails are sitting nice, everything is in time, so I reassmble and put coolant in it etc... It sounds WORSE than before!! the chatter/rattle is STILL there, but now it starts at like 1500rpm.........
So needless to say I'm pretty pissed because that was a bit of a job to do... Does anyone know WTF is going on here? could the tensioner have gone bad from being with the old worn rails? What about the idler pulley in there? it seemed a little worn when I spun it, but I didn't think it was make a sound like that....
ANY suggestions would help a ton! As it goes, I put a new Tstat in the damn thing yesterday and the bastard won't open up when I try bleeding the system.... *sigh*.. I just spent 5 hours on my car for it to work worse than before! lol thanks ya'll

[Jtuner]

oh yeah, the main driver side rail (the one that you have to take the chain out to replace) had an adjustment screw on the top mounting point.. I didn't really know what to do with this, so I just adjusted it with a flat screwdriver until the rail sat evenly all the way down..? it was just my best guess,, could this be doing it?

[Febi Guibo]

where are you on long island?

[gearheadE30]

Well, I thing that the adjustable rail should be pressing up evenly against the chain. If yours isn't (its hard to tell w/o pics) that's a possibility. Also, did you replace the chain or the gears? If you just did one or the other, that might do it. I replaced everything in the whole timing system and there is still a little bit of a deisel-ish sound when it is really cold, but I'm beginning to think that a little bit of a rattle is just normal vehicle operation.

[sheepdog]

Whoever said the rails has it backwards.
You needed a chain and sprockets. Rails will help keep it quiet, but if the chain is slapping around, it will always make noise no matter what it rubs.

Unfortunately, while just a guess, I would say within the next 5-10k expect things to go south unless you do this. A few of us have gone through this.

[DZick]

I agree with Doug (sheepdog) on this one...

I just did my whole thing minus new timing sprockets and it sounds great! but depending on the wear of the sprockets (mine looked almost like new) you might want to change them.

[Jtuner]

well I guess I'll have to go there next.. Its allright I suppose since I'll know exactly what to do this time around LOL That was a learning experience to say the least.. A bit of advise,, don't use an air ratchet to tighten the small 10mm head bolts that hold the cover on... 4 words, tap, blow, helicoil, repeat

When I got back to the shop today, I rebled the system and everything worked just fine! The car seems to even stay a bit cooler now!

Febi, I'm in the huntington area,, I live in East Northport and work at Audi of Huntington,, just started my first tech job there where you at? I remember watching a video about a certain badass m42 stroker you put together

[Jtuner]

Thank you everyone for your quick replies btw!

[Febi Guibo]

I'm in Bay Shore... denis and i can come look at your car if you want... i'm starting a new project also...

[bmwpower]

Don't replace just the sprockets or just the chain.  They need to be replaced all at the same time.  Each components wears to the others.  If you replace one, you will quickly wear out the new component.

The guides could be replaced separately, though.

[Jtuner]

Febi that would rock! I've worked on my car, but I'm seriously inexperienced with this engine.. It'd be nice to have someone with a bit more experience check it out and see if the noise is just normal... Let me know when you're free!

[sheepdog]

Don't replace just the sprockets or just the chain.  They need to be replaced all at the same time.  Each components wears to the others.  If you replace one, you will quickly wear out the new component.

The guides could be replaced separately, though.

True.
However, the cam sprockets are sometimes in decent enough shape, post a pic, I can tell you if that is the case, the others forget it, they are so small they wear fast. Keep in mind the amount you save is really not worth leaving them anyhow.

[bmwpower]

True.
However, the cam sprockets are sometimes in decent enough shape, post a pic, I can tell you if that is the case, the others forget it, they are so small they wear fast. Keep in mind the amount you save is really not worth leaving them anyhow.

Mine has 98k and they look new, but I've got the engine out of the car to do other things, so I may replace everything.





...yikes! I just priced the parts out...$600 to replace all the guides, chain and gears!  I didn't think it was that much.

[sheepdog]

Mine has 98k and they look new, but I've got the engine out of the car to do other things, so I may replace everything.





...yikes! I just priced the parts out...$600 to replace all the guides, chain and gears!  I didn't think it was that much.

Where did you get the prices from? Real-OEM?

[bmwpower]

Where did you get the prices from? Real-OEM?

Yea, actually.  Just got a qoute from BMA.  Need to tally things.