Deep Knock upon start, warm or cold (Intermittent)
 

This is my first post and I need help; after I did my first oil chnge (used Castrol 5-30 Syn), I would get a valve
rattle upon start up randomly, next I changed from a Fram filter to BMW and it stopped temporarilly but, continued later. Now I just changed the oil again but this time I used Mobil 1, (5-30) and I get a hard knock at start intermittently. Should I go to a heavier oil? ('01, 4.4, 80k).

My 2000 4.4 with 74k just started doing the same thing.

It was fine till it went to the dealer for an oil change. Ever since it has had a cold knock which goes away after about a minute. It does it intermittently.

My 01 makes a very short knocking for a couple seconds when started after sitting for a week or two.

The noise is most likely coming form the VANOS unit-apparently they get noisy on higher mileage V8 engines (more commonly on the pre-facelift M62/4.4L since it's the oldest V8 designation in an X5).
EDIT: I only use Liqui-Moly 5W40 and Mahle filters in my BMW's (E53 and E36).

Common problem after oil change on my m3 - 3.0 air gets trapped in the lifters I belive it is look up bleeding oil system you run the car at 2500 rpm for 5 miutes let it sit for 20 then do it again something like that look it up to get the correct procedures my m3 sounds like it's going to blow up when it does this scares me half to death

Thanks for the replys!
 

This is frustraiting , but good news. I thought it might be an oil pump or something. I understand machines and their personalities however, it's my Real Estate clients that worry if we'll make it to the next destonation! I'll report back on how the remidies work on mine.:thumbup:

Oil Matters!
 

I think I found the answer 0-40 Mobil 1. The dealer has always treated me well but, I question their troubleshooting skills. (Troubleshoot by parts replacement or vehicle replacement). I've used it in many vehicles and it seems to always do the trick. It's more expensive than the regular Mobil 1 but definately worth it. It starts as quietly as a church mouse. I can only guess the that the zero takes care of the finite parts (needle bearings etc) and the 40 takes care of the long term clearance wear.
:iagree:

any updates?