E34 540 smoking once in a while

[arrie50]

Hi, wondered if someone could help, once in a while when I start the car it wil give a big smoke cloud and the it is gone and then it wont do it again for a few days, the car starts without a problem and idles 100%, its just now and then that this cloud of smoke come from the exhaust. I have heard people talking about the oil seperator or the pcv that can faulty, any thoughts on this, any advice would be welcome as I dont have a clue. Thanks

 

[Raybimmer]

Only on startup ? Oil getting in combustion chamber via valve stem seals or intake route e.g. pcv valve . Remove and clean and see what pcv does for a while . good luck .

 

[Fordkoppie]

I also think it could only be valvestem seals

 

[Jandre]

Mine does the same, and so do a few others around here.

 

[arrie50]

Only on startup ? Oil getting in combustion chamber via valve stem seals or intake route e.g. pcv valve . Remove and clean and see what pcv does for a while . good luck .

Yip, only at startup, but is fast then it is gone, it dont smoke for a while and then slowly disapear, it wil stop smoking instantly, and it only does it like 2 or 3 times every 2 weeks
How do I take the PCV valve off and how must I clean it and at what must I look at to see if it is damaged

 

[Raybimmer]

PCV valve ? Hope one of the 540i guys can help !!

 

[Danzellc]

Hi. The smoking is most likely caused by oil laying in your intake manifold. The oil in sucked in through the seperator valve at the back of the intake manifold. You most likely have torn diaghram thats in the pcv. The valve can be changed without removing the intake. The other cause for the smoke could be compression in your sump caused by blowby. Do you have a nikasil block or alusil? THe pressure in the sump keeps the pcv wide open allowing oil to be sucked into intake.

 

[arrie50]

Hi. The smoking is most likely caused by oil laying in your intake manifold. The oil in sucked in through the seperator valve at the back of the intake manifold. You most likely have torn diaghram thats in the pcv. The valve can be changed without removing the intake. The other cause for the smoke could be compression in your sump caused by blowby. Do you have a nikasil block or alusil? THe pressure in the sump keeps the pcv wide open allowing oil to be sucked into intake.

What is a nikasil and a alusil?

 

[Raybimmer]

Nikasil and alusil are alloys used for bore , nickel silicone and aluminium silicone .Basically bmw wanted to make lighter blocks and the poor quality petrol in some countries caused bore wear and engine replacements under warranty . Most would have been fixed or stuffed by now .