if the chain is loose the cam can snap forward and back. The lobes on the cam will push the cam advanced when it snaps over the peak. The chain is not necessarily tight without oil pressure but the spring inside gives a little base pressure so it's not sloppy loose when first started.

The best way to confirm guides didn't break (because very hard to see the left side) is to look in the oil pan.

I would drain the oil and remove the level sensor. You will be able to see in there and the endoscope will work great.

No plastic bits you're Golden and just need to replace the tensioner. Most guide failure is from people waiting too long to change the tensioner.

I would not run the engine until confirming yes/no on the guide bits. You could take a bit of a gamble just replace the tensioner (OEM only should be about $70 Amazon). Make sure to get a crush washer and it's a trick fit on the 19mm = 3/4" head the AC compressor is in the way.

A med depth socket with a short extension works or a through hole socket with extension


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