Engine noise on cold start

[m3racr]

I have a 1995 M3 AUTO - when I start my engine cold @ idle everything is great. HOWEVER, when I shift into either reverse or drive my RPMs plunge momentarily and my engine will start to make crackling and ticking noises and a slight vibration. It also does this sometimes when it's warm and I shift into drive or reverse (dip in RMP and rattle/ticks). I can't figure out what's up.

Bad motor mounts? Doesn't explain the sudden dip in RPMs though...ugh.

My engine was rebuilt and only has 40K miles on the rebuilt one.

Any help is appreciated.

[flyfishvt]

A better description of the noise and where exactly its comming from would help. You need to stand in front of the engine while someone puts it in drive or reverse so you can do a better job of pin pointing where its comming from.

It could be nothing at all....my car makes a fart noise when I start to drive off with a cold engine. doesn't do it warm and it seems to be the abs doing a self test but I'm not 100% sure on that.

[Richkid79]

My 97 528 had a similar problem with the noise, but only did it when it sat for more than 8 hrs. It turned out to be aux. air pump. The fact that your problem only happens when you put it in gear kinda sounds to me like a transmission problem. Try to isolate where its actually coming from and check your transmission fluid to see if its low or smells burnt