Oil in me air duct

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Oil in me air duct

Post by joolie »

Im finding black oil lining the air ducts, and the filters full 'o oil.

what could that be?
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Post by Oscar »

The air duct is connected to the oil breather tube (where you pour the oil in). This is to catch the oil that is blasted at pressure back up the tube when the engine is running and that would outherwise go all over your engine. It's set up so that the oil is trapped in the air filter, enabling you to throw it out.

There's two possibilities, all things being equal: The air filter's not been changed for a while, so there's a build up in it; or the oil has been overfilled and is pushing more oil back up than normal.
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Post by jeremy »

The breather system goes via a separator (that strange black circular device on the front of the intercooler) to the air cleaner box - where it simply goes into the box above the filter - and so inevietably oil from the breather contaminates the end of the filter. On mine it never gets beyond about 25 mm and doesn't seem to cause a problem but if the engine is fuming heavily the problem could get worse.

Naturally the rest of the pipework, the turbo and the intercooler will get oily. I think all you can do is make sure that everything is clean - and if you are handy at metalwork you could fabricate an improved separator! My Renault 21 had a huge one on the front of the engine and the horrible thing kept clogging with soot - which may have been the cause of loads of ther problems. Citroen ones don't seem to give many problems.

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Post by Vanny »

Joolie you must be new to the BX, it sounds like your experiencing the special Citroen Self Preservation system!

Cunningly devised it subtley leaks oil from a number of places for no apparent reason, in order to have a fine coating of oil sprayed over everything! Might look horrible but its better than waxoyling :D

More seriously, i had the same problem recently where engine oil go onto the K+N filter (i wasn't impressed) turns out i had been a little bit too excited last time i filled her up and managed to get some oil (not a lot) into the opening to the breather circuit, this had been carried up past the seperator and into the airbox. cleaned out with air and probably spirits and it hasn't returned since!

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Post by Stewart (oily!) »

They all do that sir :)
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