Z4-forum.com

I have reported this before but my Z4 suffers badly from pre-ignition (pinking) especially when cold. I have been to the dealer twice and they say there's no error report. I have written to BMW and they have said go to the dealer to check for error codes...... I have tried different fuel grades and makes but no joy. I am entering the season where 95% of my driving is top down, has anybody else suffered from pre-ignition problems?

Are you double sure its not a rattling heatshield or a collapsed CAT in the exhaust? Does the garage agree that its pinking? Knock sensors should eliminate pre ignition on modern engines.