I'm not sure how it can be just one side. You use the phrase chain "jumped" like fell off the sprocket but there is no way you'd be able to still turn the engine to test the other bank if that happened.

When a chain comes off while running its nearly certain to break the chain.

The main chain only goes to the intake cams. there is a small chain that goes from intake to exhaust. If that chain broke and the exhaust cam is not moving you won't have compression on that whole bank (Some chance one cylinder would be closed).

I can't remember if the exhaust side is interference with pistons but I seem to remember replacing both intake and exhaust valves when recovering M62 from timing chain death.

One of three we caught before the chain broke and no head or valve work, one we had to remove both heads and replace about 8 valves, one we had to remove one head and replace a few valves.

If you have a garage to work in and a buddy to help it can be DIY. I did one basically solo in about a week

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2011 E70 • N55 (me)
2012 E70 • N63 (wife)