Hi all. Having recently sold an '87 E28 535i (bought with blown head gasket and shredded clutch), my 17yr old and I decided to take on a new project. We've been watching the Copart auctions for a while, and thought an X5 might be a fun fix and sell project. I managed to end up with 2 - an '06 E53 4.4i for $3100 inc fees (needed a new air suspension module and some other bits and pieces) and an '11 E70 xdrive 35i ($6400) with an engine noise. Both clean title / no accident damage vehicles.
The E70 / N55 is the one I'm most concerned about, and suspect I might end up putting a replacement engine in. It ran smooth when I pulled it into the garage, but there's a knock if you rev the engine to around 2000 RPM. My suspicion is that it's rod knock, but I wanted to check for loose VANOS bolts first, so pulled off the valve cover. As I was pulling the coils out, 5 & 6 were pretty well stuck, and seem to have expanded and taken in the coil shield (click for image). I bought a new coil shield from the dealer (not a common part apparently, so this must not happen often), but I wonder if anyone has come across this before?
With the valve cover off, I started finding what looks to be a destroyed seal floating around the valvetrain and in the timing chain area. It looks like rubber gasket with steel wire inside (click for image). Is there a likely culprit for this? My guess is that perhaps it suffered the issue I've read about where the serpentine belt gets sucked past the front crank seal, then the crank seal was replaced, but the damage had already been done to the crank bearings, and the vehicle was shipped to the auction. If anyone has come across this, I'd love to hear about it.
Many thanks,
Dave
It looks like you hit the nail on the head. Appears the belt was sucked into the engine, causing the catastrophic failure. And those two coils need to be replaced.
ASE and BMW Master Certified Technician
I'd get a replacement engine, replace any gaskets or seals while its out of the car, and then install it. You've likely got shredded belt material through that entire engine. Oil passages may be blocked, etc.
ASE and BMW Master Certified Technician
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