Noise at 3k rpm

[nk1221]

I have been hearing this noise lately and it is only at about 3k RPM. It doesn't sound like it is coming from the timing chain area but more from the area near the headers. What could this be?

https://vimeo.com/139525219

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[DannyDK]

My car has the same noise! At 3000rpms its starts to rattle, it stops at higher rpms. I took the front engine apart to check chain etc. To me it sounds like a piece of metal that has come loose some where, but I cant find it?

[salvuhdor]

I had this same problem. It could be many things and since you have the car and been with the car you would know better than any of us in terms of what could the problem possible be.
If this was my car i would do the following:
Suggestions
- Rail guides they become brittle and mess with the chain to cause that noise

- the Chain tensioner, nowadays many e30 owners install what I believe is the chain tensioner for an m44 engine which works a lot better (at least for me it did)

-timing system needs to be refreshed considering the mileage of your e30, check sprocket, if they are pointy then order new ones(I would just do the whole timing system) it's not that hard - just tedious.

-then after I would use slightly thicker oil.

[RCtheRed]

Hard to say, the cheapest and easiest fix would be to replace the hydraulic chain tensioner.

[nk1221]

Thanks for the replies! Looks like I'm going to work on refreshing the timing system as soon as I can.

[Tim-sutherland]

Friend of mine had the same noise at 3k rpm on an m42, had new timing chain guides put in and the mechanic was going over the engine with a stethoscope and couldn't figure it out. We went to change his motor mounts and found a piece of metal heat shield under the plug wires I think had a crack at one of the mounting points. We jammed a piece of fuel line under it temporarily and that fixed the noise until he replaced the part.

Tim

[DER E30]

Look at your engine mounts, the last time mine made a rattle like that it was the oil pan hitting the subframe... The plates welded to the subframe that the engine mounts bolt to had broken off... A good 10hrs or something to pull the suspension and subframe, weld up and put back together, ugh.

Also, the other replies have good suggestions. Good luck!

[DER E30]

http://http://www.m42club.com/forum/index.php?topic=13720.0

Look in here also, mine pulled this very same trick, mine drilled a hole in the timing case. if you pull the valve cover, there shouldn't be a loose bolt almost under the cam sprocket on the drivers side!

[bmwman91]

+1 on the top guide bolt stripping out of the head and wearing against the timing cover. Same crap happened to me and made a metallic rattle at certain RPM's.