Rattling on engine

[kwill22]

Well it's your choice. My car doesn't do that ever so I'm not familiar with it. I use synthetic also

[bmwman91]

It's either a failing tensioner piston ($40 and 5 minutes to replace) or gunked up lifters that take a while to pump up. The second issue isn't really a big deal, which is good because fixing it is more or less a full head rebuild. If it has the diesel engine sound, then it is almost guaranteed to be related to the timing chain assembly, and the only part in it that pumps up is the tensioner piston. Personally, I would buy the tensioner ASAP and swap it in. The proper way to put it in is to release the new piston (it comes compressed) before installation so that the chain isn't left loose for 3-5 seconds on first start. The manual says to put it in compressed and let the flailing of the chain pop it free, which seems like a mind-blowingly bad idea, so don't do what the manual says in this case lol.

[oldmann]

Does sound like a diesel, If I let the oil level drop to 1/2 qt. low or lower its noisier on startup for a few seconds longer.

All new timing components going on in June, Gonna pull the head and freshen it up too. New lifters also. Been gathering parts for a year.

[kwill22]

Deffinately Agree on the tensioner issue though. And I always put mine in expanded. Never thought the whole chain slapping and releasing thing was a good idea.