Cold start rattle 2-3 seconds then gone.

[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.

[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.

[Cmamainer]

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

[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.

[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.

[Moi]

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

[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.

[Andratch]

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.

Did you end up replacing your oil filter housing, and did that fix the problem?

IMO this totally feels like a tensioner-not-tensioning issue, but like others I also have a new tensioner, so I assume there's some sort of pressure leak somewhere in the system. I didn't realize the oil filter housing had anything to do with that, and I'm willing to give it a shot, but at $500 for the part and pretty labor heavy to get out, I don't want to just throw it at the car for fun.

[TexaZ3]

Check valve in the oil filter housing?

[Andratch]

I think I have this sound. It's the loudest when the car has been sitting for multiple days without being started. Then on first start only, I hear it for about 2-3 seconds. After it has been started once - even for just 5 seconds - I won't hear it again.

Leads me to believe it's the tensioner, but mine is new. I don't know if there's a wrong way to install the tensioner...I just tightened it in until i hit the torque spec.

In this video you hear it just briefly at the 5 second mark. It's not as loud as it was this morning when I started it for the first time in a week.

[lemoose]

I think I have this sound. It's the loudest when the car has been sitting for multiple days without being started. Then on first start only, I hear it for about 2-3 seconds. After it has been started once - even for just 5 seconds - I won't hear it again.

Leads me to believe it's the tensioner, but mine is new. I don't know if there's a wrong way to install the tensioner...I just tightened it in until i hit the torque spec.

In this video you hear it just briefly at the 5 second mark. It's not as loud as it was this morning when I started it for the first time in a week.

I have this noise too- I thought it was normal though?

[Andratch]

Check valve in the oil filter housing?

That seems like the consensus so far, but not many people have taken on the fix and reported back on it. I guess it makes sense....we've all replaced the chain tensioner, and it doesn't sound like it could be the guides. Logically, something that's allowing oil pressure to drop at the tensioner and then be rebuilt in the first 1-3 seconds after startup would be the cause.

I went ahead and ordered one from FCP along with a new tensioner, idle pulley, bolts and gaskets....we'll see if this is the fix!

[Andratch]

Got the old oil filter housing out today, did not need to take off the fan. It only took about 45 minutes, not a difficult job…don’t let it intimidate you.

All you have to do is take off the intake (not the plenum, even with CSL intake), remove the driver side fan shroud piece, release the serpentine belt from the alternator, remove the alternator itself (two bolts, one clip, and one nut), then one bolt for the oil cooler lines, 6 bolts for the housing, and 2 bolts to separate it from the power steering pump. Easy peasy.

The tensioner comes out with the assemby, so I'm just going to replace that and the idle pulley at the same time because they're cheap and mine are original.

new one from FCP gets here tomorrow, we’ll see if this is the fix we’re looking for.

[WestBankM4]

Did you end up replacing your oil filter housing, and did that fix the problem?

IMO this totally feels like a tensioner-not-tensioning issue, but like others I also have a new tensioner, so I assume there's some sort of pressure leak somewhere in the system. I didn't realize the oil filter housing had anything to do with that, and I'm willing to give it a shot, but at $500 for the part and pretty labor heavy to get out, I don't want to just throw it at the car for fun.

I did not do mine yet, I actually have the Karbonius CSL airbox going in after I'm done with my interior. Was planning on knocking it all out at the same time considering I'll have to remove the factory intake manifold.

Like you, I bought an OEM oil filter housing, the oil cooler o-rings (thanks Heinze) and a new OEM tensioner since that was the first part I bought after reading this thread. Problem is, it's still in the box in the garage haha. Let me know if it solved your issue please, regardless I'll be installing those pieces shortly.

[maupineda]

Not sure the housing remains filled, my car does not have the rattle, and in the last oil change I paid attention it this, when removed the lid, i checked if there was oil in the reservoir, and to my surprise it was not full with oil.