Cold start rattle 2-3 seconds then gone.

[Lavatoad]

I think I have a similar issue. After the car sits overnight, I get a rattle for the first 3-5 seconds on the first start. No prolonged oil light, and it won't happen if the car has been recently driven. The sound also ends very abruptly, like flipping a switch (or sufficient pressure built).

Going to try to pinpoint, but sounds like I'll be replacing the housing.

[Moi]

think i may have this sound as well. does anybody have a video i can compare it to ?

[heinzboehmer]

The new filter housing comes with gasket and a BMW oil filter, no oil cooler O rings though.

Oh cool. Did not know that.

[Cmamainer]

Good time to replace the oil filter housing gasket (11421719855) and oil cooler o rings (17222245358) too.

The new filter housing comes with gasket and a BMW oil filter, no oil cooler O rings though.

[Cmamainer]

A normal amount of time, the rattle only lasted around 1 to 2 seconds

[eacmen]

No, I was in contact with a member from the old forum that went by the name "Zaharias", he was having the same exact issue and had rebuilt the vanos like I had and changed the rod bearings with no improvement. His mechanic recommended changing the oil filter housing believing that it was allowing oil to drain from the topend while sitting for extended periods such as overnight and it seems he was correct.

How long was your oil pressure light staying on during cold starts? Seems like if that check valve was bad then it would take longer to build pressure.

[heinzboehmer]

I'm having these exact same symptoms, funnily enough, it only started happening AFTER I completed my top end rebuild. It has been making a rattling, knock sort of noise for 1-2 seconds upon a cold start, it's always in the morning when the car has sat overnight. Vanos has been upgraded to Beisan and had less than 500 miles on it at the time, so I knew it wasn't that but I too searched high and low for the source. Sounds like you found the culprit for me, I appreciate you updating this thread. Going to order an OEM piece and get to work, most likely upgrade the pulleys since I'll be in that general area anyway.

Good time to replace the oil filter housing gasket (11421719855) and oil cooler o rings (17222245358) too.

[WestBankM4]

I'm having these exact same symptoms, funnily enough, it only started happening AFTER I completed my top end rebuild. It has been making a rattling, knock sort of noise for 1-2 seconds upon a cold start, it's always in the morning when the car has sat overnight. Vanos has been upgraded to Beisan and had less than 500 miles on it at the time, so I knew it wasn't that but I too searched high and low for the source. Sounds like you found the culprit for me, I appreciate you updating this thread. Going to order an OEM piece and get to work, most likely upgrade the pulleys since I'll be in that general area anyway.

[sapote]

To anyone who is still having this issue I replaced my original oil filter housing with a new one and the cold start rattle is gone.

Makes sense if the engine oil was drained due to the plastic check valve cut a slot on the OFH.

[Cmamainer]

No, I was in contact with a member from the old forum that went by the name "Zaharias", he was having the same exact issue and had rebuilt the vanos like I had and changed the rod bearings with no improvement. His mechanic recommended changing the oil filter housing believing that it was allowing oil to drain from the topend while sitting for extended periods such as overnight and it seems he was correct.

[eacmen]

To anyone who is still having this issue I replaced my original oil filter housing with a new one and the cold start rattle is gone.

What caused you to take this action? Were you observing low oil pressure?

[Cmamainer]

To anyone who is still having this issue I replaced my original oil filter housing with a new one and the cold start rattle is gone.

[sapote]

I have replaced the chain tensioner with no improvement?

Use a pressure gauge to monitor the oil pressure at the vanos banjo bolt, to see how fast it drops after engine turned off. It's good to get this out of your mind, but I doubt the vanos can cause the rattling noise of a chain at start up.

[Cmamainer]

I have replaced the chain tensioner with no improvement?

[sapote]

I'm at a loss up to this point, It seems like oil is completely draining from the vanos after engine is shut down for awhile. I tried a new accumulator but that didn't change anything, but like yourself it runs great and pulls hard with no check engine light?

What if the chain tensioner leaked the oil and took a few second to build up pressure? I don't think vanos is the issue in this case.