Originally Posted by waynec
do you have solution to your cold start loud noise? i had the same issue..pls share if you have solution to this..thks
I pushed the issue hard with the dealer and BMW. It is NOT normal and you should not accept it.
NOTE: There is a bit of a light noise on startup with pretty much any VANOS engine - don't confuse this with that. VANOS coming up to pressure noise is normal.
So here is how it played out for me. (Could be long...)
*** Phase One:
I took recordings of my cold engine startups over 2 weeks (bonnet up, iPhone close by, but not in the engine bay). I was able to capture 6 very loud examples of the noise. I emailed these to the service dept (after telling them previously what I was going to do). These sounds ended up at BMW head office and eventually to BMW Germany.
Germany was sure it was the crank and crank bearing shells, so they sent a brand new crank and full set of bottom-end bearings. I got a call from the service dept who took my car for a week and pulled the engine out and rebuilt the bottom end. A M mechanic from head office was there to supervise. (Got a M3 vert as a loaner too. Sweet.)
Got the car back, sounded great! Then on the 3rd morning, the noise was back. Over the next 4 days I recorded it 4 times. It was almost worse. I rang the dealer, sent in the sound files and they asked for the car back.
By this stage BMW was very very interested. They asked if it was OK for the M specialist to take my car home for a few days - I said this was fine. That was a good move because it did it to him - and he was horrified at the sound!
*** Phase Two:
They called me up to tell me this news to which I replied "Surely it must be time for germany to send a new long block over and just get this sorted." They said they would do all they can, but were unsure what the sound/solution was. They were banking on the crank fixing it.
I got a phone call 3 hours later that day to inform me that BMW Germany was express freighting a !!Brand New!! engine for me.
5 days later the engine arrived, it was put into my car. (Germany wanted my engine shipped back untouched - I wonder why...)
I had to run it in (1200 miles of painful slowness) and it has since been perfect. No sound, awesome performance, happy man.
That is my story. It has been 9 months since that change and it is still great.
The BEST thing I did there was take some good quality recordings with date/time stamps over a 2 week period. Germany will be very interested to hear these sound files (send them as .mp3). I was patient and didn't ever lose my cool either.
Here is a recording of my sound: http://m-works.co.nz/M3Rattle4.mp3
You can hear the noise just after the engine fires. It was MUCH louder in real life.
Insist on a solution.