NITROUS OXIDE ( nos / n2o ) advice forum

The huge belch of smoke on start-up and my increased oil consumption prompted me to do some checks today.
It took me 4 hours to complete the job and I ache like hell. (I need a Jason )

There is no oil or coolant cross contamination
My lowest cylinder pressure was No.5 at 180psi, the rest were all at 200psi
All plugs were fouled and once cleaned up, it ran as sweet as ever.

The remaining conclusion is a problem with the crank breather, as friends on here have already suggested.
The bimmer forum says its a common problem and the symptoms are text book.

The crank breather will be replaced ASAP

Rich ,try replacing the PCV valve with one from a turbo model it might be more restrictive ,i have the same problem with the truck along with many others, seen all sorts of ( cures ) can you post up a diagram ? i can see if any could be applied to the bimmer

Hi Austin, I've been trying to find a diagram most of the day and I've lost the electronic copy of my workshop manual
My engine is the M62B44 - 1998

PS: Congratulations on a new PB

Thanks ,

Just a sketch would do of whats there

Austin

have you looked here ritchard.....http://bmwfans.info/parts/catalog/E31/C ... 98/browse/

Heres is a link to the 840's crankcase ventilation diagram

http://www.realoem.com/bmw/showparts.do ... g=11&fg=15

Cheers

Was going to suggest an oil separator but its already standard fitment, if you haven't checked it i would make sure the drain tube isn't blocked along with the O/S itself . Is it pulling oil into the inlet manifold?

Austin

New PCV has been ordered (£49), will be fitted this week.
Interestingly, having spoken with BMW, they now regard the PCV as a serviceable item very 30k miles, so mine is way passed that.

I'm pretty certain I'm missing something.
The item I have just collected has no valve mechanism, all pipes/orifices just blow through, so how the hell is this going to work?

I reackon the part I need is an oil separator as per Hadi's link.
Trouble is I don't know where it's located in the engine.

I'm so confused: I just found this description which would indicate I have the correct part, but how can that be when I can blow through every pipe, where's the valve or does pressue/vacum trigger it?

The blow-by gasses which are produced during engine operation collect in the crankcase.
The intake system is connected to the crankcase by means of a pressure control valve integrated in the end cover of the intake
system. The resulting vacuum draws off the blow-by gasses in the crankcase via a cyclone separator.
The oil vapours contained in the blow-by gasses condense on the cool walls of the cyclone separator and are returned to the oil
sump via a return line. The remaining gaseous components are fed via a distributor pipe in the intake system to the mixing
chamber in the throttle housing.

Works a bit like a Dyson as the oil vapour is spun round it condenses on the cooler external part of the valve and should drain back into the sump, when it gets fitted make sure the drain tube is not blocked , the valve it self should flow air freely. Just to add its the O/S (1) in the dia that returns the oil .

Austin

I've ordered an Oil Separator as well. Booked in for Wednesday.

Going to have to look at this at our next GTG , need something for the truck .


Austin

I've never seen any sign of smoke from your truck except from the tyres

only on cold starts after its sat for while, although not allways
Rich have you got the burn outs sorted yet?
Austin

Nah, I don't have a LSD, so I'm not going to bother anymore

I spoke with the guy that rebuilt the engine last year and he assured me he changed the oil separator, but not the PCV itself. So I'm hoping that there is obvious oil contamination in the inlet manifold.
I also had a play with the PCV last night and it DOES have an integrated valve that triggers when I blow into one of the ports, so I'm feeling a bit more confident.

Austins Truck often gives a good belt of blue smoke when he starts it...

He cant see it but we can

The reason I'm being so anal over this is because this 2nd engine smoked from day 1 even with all the work done to it, whereas the original engine never did, but that engine was destroyed (court case continues).

I have a glimmer of hope as for the true reason for the smoking (apart from the PCV) but still relative to the PCV. I will know the truth tomorrow. While the car is in the garage I will be in court about the other matter

Hopefully no more smoke and looking good so far
Big thanks to Hadi for supplying the diagram of the manifold that identified the problem, which was two fold.
The PCV was replaced as a matter of course, but the reason for the smoke was due to a modification that was missing on my manifold.

The manifold was full of oil.
There should have been a pipe running the length (inside the manifold) from the PCV to a pick up at the front, but instead all the oil was being dumped into the manifold due to the faulty PCV. The return pipe to the sump was clear, so now its all reconnected.

The engine runs slightly differently, probably due to the change in vacumm pressures, but it seems to be settling the more I drive it.

One fall-out from this, is that my traction control light has stayed on, which indicates NO traction contrrol, this will have to be addressed when I return from holiday

When are you going on your hols Rich??

sunday morning, return May 4th

I'll pick up the rad when you come back then..
Pel

Glad I could help Rich

Cheers