They don't replace heads any more on these. They have ordered new exhaust side lifters. Service advisor says they have two other cars awaiting the same, and they are on national backorder.

 

What was the original problem that led to this?

 

Just tick tick tick tick noise loud at idle - worse when the oil was thin and worse when it's cold out. I've complained about it on 3 service visits and they already did the "bleed down" with no change.

 

have you checked the spark plugs? i've heard that when spark plugs are loose, it can cause a tick/chatter... just an idea...

 

I took it to the dealer with the complaint of ticking. I hope that they would have checked for other causes, but who knows.

 

I thought that it was normal for most cars to have lifter noise when idling cold. Was the tick tick tick noise always present, even after initial warm up?

 

This is a known problem with this model. The Service Advisors are relunctant to correct the problem because its fairly labor intensive and therefore expensive to BMW if your car is under warranty.
I believe, in order for a resolution, you must complain about the noise several times (over a period of time) before they are willing to take any action on the issue.

 

Loudest at idle, but persists even when the car warm - most notable when it is cold outside. I could drive 10 miles home from work and stop at my mailbox and hear the ticking.