Ammar545i

Alright, I have an 04 545i sport pack and I noticed that the car has a very slight shake to it when it is idling. When you rev it slightly it shakes when the idles come back down. Is this normal for the N62 engine? The rpm sits at 500 which seems a little low to me.

turboawd

eh, sounds normal for the most part. you could do some basic maintenance to see if you can help smooth it out. clean maf sesnor, change plugs, add some fuel injector cleaner, etc.

500 is normal.

AchtungE60

500 is normal. your problem could be from many things including but not limited to motor mounts

Ammar545i

alright replaced the plugs with ngk iridiums, and Achtung, I appologize for being rude to you in that other post. You really think motor mounts, cause this? Wouldn't I feel it when I switch reverse to drive?

turboawd

what kind of motor mounts do our cars use by the way? and do they wear out??

Gilgorm

Not sure about BMW mounts but two of my retired MBs needed new motor mounts. The very slight shake was usually noticeable in either D or R since the engine shifts slightly depending on which forward or reverse gear you are in. The older the car or a high mileage car can develop worn or cracked mounts as the mount material dries out (believe it is rubber but not sure).
BTW, my retired E60 idled in the 600 rpm range.

KLR4LIFE

I get the same thing the OP stated but its not bad, i feel a slight shake when the car is idling, i willhave my mounts checked out but im not going to do anything unless it gets worst. I have a 6 speed, it maybe just me being anal, when i rev the engine the car rocks a little but isnt that the beast coming out? LOL

Gilgorm

That is the beast. When the engine is revved, the torque causes the engine to twist slightly on the mounts and that action creates a rocking motion in the body. We can only feel it when the car is stopped. If cars didn't have mounts the car would be very uncomfortable.

AchtungE60

Yes of course motor mounts cause this. But since you changed nothing but the spark plugs it could be a an idling issue did you do anything else with the valve cover or anything that may have caused a vacuum leak?