a little help pls...

[s2driveruk]

So after the track sessions yesterday, car was idling poorly, actually stalling on a couple of occasions on the way home.

Added to that it had decided to eat 1/2ltr of oil and on warm starting, was greeted with a cloud of white smoke On the final session I did, it felt low powered 2-3 laps in and on looking this morning there appears to be black sooty spots over the back of the car so i have a boost leak too

Anyway, removed the airbox to get at the Lamda to sort the stalling/poor idle issue, this is what it looked like:



It was dry and lightly wire brushing it the brown (burnt oil???) came off

I had run the car for a few seconds before removal to see if it belched more white smoke from true cold start and nope plus it idled ok too - what does that mean then

I could see once the maf was removed that the intake path was soaked in oil:

intake to MAF


off the metal pipe from the I/C to the one over the rocker was literally dripping in oil


Kinda answers where the oil was going then...PCV..which if the oil was pooling in the I/C would have driven up the AIT temps which may had made the car feel lumpy/low powered i guess

I whipped off the PCV valve and it looked clean enough and there was plenty of oil in the pipework - the whole circuit was replaced in the summer so its not gunky etc Would it be a faulty valve causing the oil to get round in big amounts? the valve has a date stamp of 2007 so its not old (less than 5k miles I'd guess)

Sooooo, what would cause the white smoke at hot startup? I hadn't run it at idle for long after the first session so i wonder if the oil in the intake had seeped somewhere and then got burnt off on restarting the car.

Any ideas?

Cheers
David

[andy10v]

Fit a catch tank

[s2driveruk]

yeah was thinking the same thing

[andy10v]

I would recommend it. I found whenever the car was driven enthusiastically it barfed oil out the breather on the back of the head and coated the intake hoses in oil, looked similiar to yours. Fitted a catch tank and nice clean boost pipes.

However in my case I think that is a band aid solution, I don't want it to chuck out oil, I want to try moving the cam cover breather from the back of the head to the top as it appears to be hard acceleration that was causing it to barf out the back.

[Acidburn]

yeah was thinking the same thing

If you want to try a catch tank I have one spare

[newsh]

I think the oil comes from the crankcase vent when you go round hard right handers on full boost You need a surge pot halfway up the breather.Mine was filling the catch tank every session last time at CC..

[s2driveruk]

If you want to try a catch tank I have one spare

Pete, if i wanted to try an S1 you'd have one tucked away somewhere

Will give you a bell as I think I have the same issue Newsh is mentioning.

@John, did you get white smoke too???

[Jamo]

This is why mine would go on track until I've got my forth coming RWD19T / Rusty catch tank and oil separator installed.

The stock take off on the back of the cam cover on hard acceleration forces oil through it when the nose of the car lifts.

[s2driveruk]

if that accounts for the consumption and white smoke then i am sold

[Acidburn]

Pete, if i wanted to try an S1 you'd have one tucked away somewhere

well now you come to mention it :mischeif:

[Rusty]

Mine was putting ~150ml of oil a session into the catch per session. Without the tank, a chunk of this will get into the inlet and result in what you have there. Obviously the catch tank doesn't stop everything but it's a damned good start

I've worked with a number of people on catch tank installs and there are a number of tricks that can be employed for cars of all power levels and useage.

I've not heard the theory that Jamo mentions but it would compound the issue that I know to be the major one - oil surge when cornering right under power. When applying the power on the exit of a right hand corner, the oil breather on the block forces oil up the system, if the head breather is already choked then this will mean that the oil can only go towards the inlet return and result in what you have there, an oily mess.

The solutions available are:-

• Oil swirl pot
• Catch tank
• Catch tank with sump return
• Combination of the above

For a modest road car you don't need a sump return, as above, the amount of oil going into the tank is small and a sump return will just get white gunk into your oil system dring normal driving. In 2 years' driving with the catch tank, it's never once filled up, even a bit with oil, only condensation. For a track car of the same ilk you can accept a sealed tank (no sump return) but you have to empty it and top up the oil.

For higher power you do need a catch tank, even for the road, as the higher crank case pressures are an issue, as are the higher g. RWD19T has proven this on his S6.

For a powerful track car you need a separator and tank or correctly baffled tank that returns to the sump. A sealed can will just fill up and stop working. Newsh experienced this at ADI 09 with his 3071 3B.

I have one more idea for this - an expansion chamber in the catch tank pipework that is also a semi swirl pot. The idea being that the surge of oil is foiled by a baffled, coke can sized chamber that can accept the surge and then allow it to drain back through the breather. Obviously this isn't ideal as the breather is there to breathe, not drain but this process will occur naturally, in fact the system is designed to drain any surge back in tis way and it does get rid of the need to remove the sump to fit a return. I would use an enlarged pipe to enable this to work properly and run the head outlet to this can to ensure best operation.

[s2driveruk]

will give you a bell later Andy, non return sounds about right to be honest