Oil trap ?

[martauto]

1999 318 ti

There is a small black circular object @ 25mm deep and @ 75mm diameter to the rear of the inlet manifold and connects to the top of the cam cover. When I spray "Bradex" over it , the revs pick up and seems to calm the lumpy idle and when the engine is switched off, it seems to "hiss" for a few seconds.

Am I correct in thinking its an oil trap and can I replace the item ?

Cheers, Mart.

[jimmyspeed]

its a crankcase ventilation valve

I'm pretty sure the hiss is normal, don't think it should draw in air though.

id look towards the idle valve for a lumpy idle, you can disassemble and clean it but if you diagnose the ccv i bought a febi replacement for my e36 and ran it for about a week before the clutch went and i scrapped the whole car - its boxed and i have a receipt if you need one make me an offer its currently a window sill ornament

[maxfield]

I can't for the life of me recall what it's called.

But I have changed a few of these due to them causing idling issues.

[sag]

I can't for the life of me recall what it's called.

But I have changed a few of these due to them causing idling issues.

I think either crankase ventilation valve
Or oil separator valve

[jmc330i]

It may be the picture, but it looks like there's a hole in the top??

[CarbTuner]

hi Martauto,
I confirm what JMC330i has just said, there is a crack in that part. Try blocking it off with some silicone or something, it surely draws in air through there...

[Andyboy]

Put your finger over the small hole on the valve - if the idle changes dramatically, it needs a new one. Check the various breather hoses - some very late M43 and M44's don't have an idle control valve as such and have a hose from the inlet bellows under the manifold to a breather rail. This can pop off and cause a terrible idle.