I recently purchased a 2007 328 xi with 24,000 miles. This is the first BMW I have had in years. I can't tell you how nice it is to be back in a BMW again. I really missed the drive. I have had the car for about three weeks now and the other day I noticed a knocking noise coming from the engine when it first started up in the morning. After about 10 minutes of driving the noise went away. However the noise came back once the car sat overnight and completely off again. The sound is a little like the sound a car makes when the oil level is low (valves knocking) but I checked the oil level and it is full. I was wondering if anyone had an idea what may be causing the noise and wat needs to be done to correct te problem?
Most likely the hydraulic valve lifters - known problem on the N52 engine. Not hurting the engine but BMW has replaced quite a few cylinder heads to satify customers.
It is parked in a covered garage that is exposed to the outside air. Temp is approximately in lo 60's. The problem seems the worst when the car sits for extended periods of time without being driven.
Sounds like the Valvetronic tick. I have a 2008 E91 and it occasionally ticks at idle when started after sitting overnight. This is somewhat common and should not be a problem unless it gets really loud and does not go away after a few miles of driving. Is you car still under the original warranty?