M50 noisey lifters when hot?

[Aussie525i]

Hi all,

Any ideas on a noise which appears to be coming from the front of the engiene? It is fine on start up, and when cold, has the normal M50 start up rattle in the lifters for half a second, then is quiet. It only makes a tapping noise when it is hot, and you rev it, then back off back to idle, then it will tap, tap, tap for about 10 seconds, then go quiet again.
Any help would be appreciated.

Cheers

David

[xspeedy]

Have you had a good injector/engine cleaning lately? Not Techron in the tank, but something like the BG44 cleaning done at a shop? I had odd cold engine tapping noises that went away after doing this. I guess a lot of carbon can lead to weird noises.

[russiankid]

Vanos likes to make noises when its showing signs of wear, and its located in the front of the engine.

[xspeedy]

Vanos likes to make noises when its showing signs of wear, and its located in the front of the engine.

Yes, and having just replaced mine using drvanos' kit, a worn out VANOS sounds kind of like a diesel at idle. If you rev it, you'll hear another loud noise under the hood that has been described as rocks in a can. To me it sounds more like a coarse metallic buzz that is obvious from the VANOS unit itself.

http://www.youtube.com/watch?v=yOxd-O6NtDc

[russiankid]

Does your idle still lope a bit after you released the throttle? Mine does the exact same thing. It will lope down to 600rpm, and then come back to normal idle.

[Aussie525i]

Is not the Vanos. I had the Vanos replaced a year ago, and I know that sound. It is different to the vanos noise. Revs don't dip after reving. It just sounds like a metalic tapping sound, then disappears agin. I was thinking it could be the timing chain? Do you think the chain could make that type of noise, or is it likely to be a lifter?

[yaofeng]

The hydraulic lifters making sound on a cold engine is quite normal. Oil drains out of the lifters gradually when the engine is shut down. If the noise disappears when you give gas or when it is warmed up I wouldn't worry about it.

[russiankid]

I've never heard of M50's having issues with the timing chain. What weight oil do you use?

[Aussie525i]

Castrol Magnatech 10w - 40w

[bmwrp8]

Castrol Magnatech 10w - 40w

try using 15w-50w or 20w-50 and see if it goes away... but i use the same oil as you in all my bmw even the m54 but no ticks. wouldn't hurt also if you check your chain and vanos too it''s better to know the problem while it's in its early stage