I have a 2001 X5 with the M62b44 with 137k miles on it. Ever since I bought it at 129k miles sometimes it would rattle on startup for 2-3 seconds then go away and run normally. I tried replacing just the timing chain tensioner but the problem persisted and since I had no record of the chains being done I did them myself with all genuine or OE parts. Replaced the chains, tensioners, and all guides. No sign of any carnage on the old guides they seemed to have held up well but I was glad I did it anyway for piece of mind.
Now since the timing chain job, I still notice some rattling on startup. This seems to be random but mostly after the car has sat for 24 hours or more. Since the chains and guides are all new I started wondering if it could be an oil pressure issue. I started it up today and noticed that when the chains do rattle for 3-4 seconds the oil light takes slightly longer to shut off. When it starts up and doesn't rattle the oil light shuts off immediately when it fires up.
Things I have replaced already:
- Full timing chain job
- Oil filter housing with check valve
- Oil filter housing O-rings between the adapter plate and the block
One thing that I'm wondering is if maybe the oil pump pickup O ring is leaking internally and making the oil pump suck air for a second or two on startup. Can this pickup tube be accessed by removing just the lower oil pan? I really don't want to pull the upper oil pan since it requires so much to get to it.
Part 4 on
this diagram is what I'm referring to. Any other ideas?
12-17-2023, 04:07 PM
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