95 325i Stumbles around 4.5k RPM

[JLong]

Just bought a 95 325i with 120k miles. The car has been taken well care of (or appears to have been). The problem I have is there is a stumble around 4k and just before 5k, after 5k she screams to redline. anything under 5k seems really slow to me but my other car (98 SS camaro) will do high 12's in the quarter so maybe I'm just a little spoiled on straight line acceleration. I love the BMW's handling but need the engine to perform as well. Just to sum up: Slow untill 5k, with a stumble at 4k and just before 5k.

I've spent all my money so I just can't start replacing everything. need some help.

[Kevin325i]

Could be the vanos being stuck or not functioning properly. You might want to have it looked into by a shop. Or try searching the forums for more info on diagnosing the vanos failure.

Kevin

[JLong]

Pardon my ignorance but do the US version have the VANOS?

[BeemerMan]

shit! my car sceams at 4 1/2 or 5 too. what could be the problem?

[Kevin325i]

Yup they do. It could be the vanos, but it could also be your mind playing tricks on you. I think the torque curve is supposed to hit at like 3200 though so it sounds more like the vanos.

I really can't coment on what it should feel like because my engine doesn't have the vanos and I've also go different cams than the other 325s.

[Deloriant]

What exactly is VANOS?

[Kevin325i]

*trumpets sounding* Hey look another FAQ

[JLong]

Any tips on troubleshooting the VANOS unit? I'm very mechanical in nature and would rather fix anything myself rather than take it to a shop (i'm a little more picky with my car than a mechanic would be). When it comes to a push-rod v8 I have no problems, but i've never messed with a overhead cam or anything like VANOS units before.