oil catch can on tdi's

[modman]

has anyone put an oil catch can on their tdi to stop oil blowing into the air filter housing?(through the crankcase breather)
there doesn't seem to be a lot of oil but it spreads out over the filter reducing surface area and its a pain to clean off the inside of the housing
david

[ISUZUROVER]

Actually the oil on the filter improves the collection efficiency of the filter for dust, rather than decreasing surface area (which it may do to a very small extent, but the oil coated region will still have air flowing through it). It may cause a slight engine performance decrease though, but probably not noticeably. If you are really interested I can give you graphs that prove this...

If you really want to do something about it, the best thing to do would be to buy an oil/water separator for an air compressor (the type without a regulator) and fit that to the line before it reaches the air filter. You will have to periodically either return the collected oil to the engine or fit a return line to the collector bowl so it does it automatically.

[Bush65]

The plastic cyclone separator on the right side of the valve housing is supposed to prevent the oil carry over. Have you tried cleaning out this separator to see if it helps?

[modman]

i don't know if the crankcase pressure is too great or the valve has shat itself, but most tdi's i've looked at do this too some extent.
where it enters the intake system is after the filter so some goes through the turbo and some gunks up the pipe between the turbo intake and thefilter housing. i've already blown the excess out of the intercooler once before. i've talked too fred smith and he reckons bad rover design
what about a catch can thats vented back into the system again at the same junction on the intake.
on turbo conversions i've done before we used to put one of those push in/on k+n filters straight into where the pcv valve used to go.
but when racing you had to run a catchcan.
i'm just trying to stop the muck entering the intake system(pita to clean)
i don't believe this closed system is necessary for the tdi to run efficiently.
(not worried with legalities at this stage)
david

[sclarke7171]

I've looked into this also.
Reason is this.
if you get to much build up of oil in the intake system the engine can run on its own oil.
Diesels will do this and have been known to run on their own oil. its not uncommon in cars, but in Trucks its the largest failure of engines.
As soon as they start to run on their own oil, you cant shut it off and it will keep running until it self destructs.
i've seen a cummings deisel in a boat do it and it was very interesting.
The damage is not just a quick rebuild.

So there are 2 options.
bigger catch can or keep and eye on it.
I'm going a after market catch can. Alloy one. about $60
Avail from Ebay.

Steve