It wouldn't hurt to stop by the dealer and ask what their thoughts are.

Road debris damage would most likely evidence itself by loss of engine oil, leading to subsequent engine failure. The damage site can be seen during investigation.

Yes, a bullet can damage an engine, but there is usually a path to follow from the point of entry to the vehicle, to the damage site.

BMW has not stood behind their window regulators, nor have they stood behind their driveshaft splines. (I'm about to enter a steering shaft double U-joint replacement episode that surprises me too).

They weigh the potential cost of a recall to safety liabilities, with the outcome (when an engineering or material defect is identified), often being a service bulletin authorizing repairs under warranty "if the customer experiences the particular condition". This implies there could be many engines operating with the same potential failure. But the likelihood of occurrence does not warrant a general recall.

This is one time that having a good relationship with a dealer could have paid off in some assistance from BMW. Perhaps they could have furnished some of the components at a reduce cost, etc. Unfortunately, unless an engineering deficiency or manufacturing process defect can be proved, I think chances are slim of any BMW intervention.

2002 X5 3.0 237,000 miles
2004 325i 106,000 miles

I know i am way out in the left here... however, a BMW is not a Trabant... while i fully realize that the warranty is long gone, and even if it were a CPO, that would have been gone as well... My point is to INVESTIGATE the problem and put the issue to rest - based on the service records (as per OP), the car is taken care of, and then the car gets a bullet in a forehead... we need to know whether the bullet "killed" the car or internal cancer got to it a split second before the shot, so to speak... and we need to know where that bullet came from - the unexplained factor is THE worrysome factor...

As far as bringing engineers from overseas to address something - I had a factory engineer fly over from Scottland to US to address an issue in a $25K piece of equipment - all we asked for, was to have a replacement shipped to us, for which we would have paid (just buy another unit) but the factory WANTED to know what the problem was as it was not something they could replicate... That is the auspies that I am suggesting a "heart surgeon" take a look to see what happened...

On a side note - could it be that there was a road debris that hit the engine (I had my fuel tank punctured once) or a REAL bullet (stray bullet) hit the car? In my line of work i had seen cars with bullet damages (non-armored cars) but I can't tell if a bullet can actually "break" the engine wall...

Term--I didn't remember what a Trabant is. Perhaps there are other so here is a link: trabant - Yahoo! Image Search Results I would like to give one to my x wife.

If the damage was caused by a bullet I suggest that rather than worry about fixing his X OP priority should be to move out of that neighborhood.

If it was road debris OP must have had the music reeeeeeeally loud.

I bet the engineer was jealous of the marketing guys going to all the cool places, couldn't just ship it back to the factory?

I just found a thread with some very upset 5 Series owners with N52's over on edmunds.....
There is talk of a admission of factory defect on the head bolts as well as a class action lawsuit forming.

2006 BMW 525i (N52) possible wide spread defect - Car Forums - Edmunds

NOT COOL

I've got an N52 in an X3. So far so good. I thought you had an N62 V8 though. Is there a suggestion that this bolt issue on the N52 also applies to the N62, and is that what happened to your engine?

I also had an N54. The relevance is that it had the HP fuel pump issue. There was talk of a class action lawsuit in the US, but I don't know if it went ahead or not. Not likely it would have had any effect in Canada. Anyway, I had an early fuel pump failure, within the first few months. The dealer fixed it promptly under warranty. Then I got a letter a year or so later, advising that because of their wish to ensure customer satisfaction, my engine warranty had been extended to 10 years, at least for the fuel pump portion. That extended warranty was also transferable. Then, another year later, I got a letter saying that they now had a new fuel pump in production, and would be changing them all out. I said it was working fine. They said that they were sorry for the bother, they would schedule it at my convenience, and they wanted to make sure it ran fine for the long haul. They changed it again, and I never had any problems subsequently. That was an example of standing behind a product. I thought that was cool.

Wow talk about stark contrasts.

I had a 2006 350Z. It's motor was a 1 year horror that ate rings. Nissan replaced it with an identical motor at 45k and gave it a 12/12 warranty. Motor 2 lasted 18/18 and they told me to f00k myself.

I sold it after replacing the motor and will never buy Nissan again.

UPDATE:

Engine/Trans pulled from vehicle

Top end stripped down and cylinder heads removed.

1 Stuck valve on passenger side resulting in the roller being ejected through the top of the cylinder head.
"The valve's were caked on that one. Thanks BMW for your excellent valve seal engineering on these N62's"

Pistons look good/bottom half looks good. Cam/valves compromised on pass side.

Sourced new core for Passenger side head with the hole in it. Complete W/ Valves & Cams ect.

Then I shipped the heads out to Sheldon @ Autohead Performance for new seals/3 angle valve job/polish/resurfacing ect.

I will upload some pics tomorrow.

Keep up the good work!

Any pics?