Thread: smoke from catch can

First of all undo the engine's oil filler cap at idle to see if there is no excessive crankcase smoke or pressure (blow by), i made a video how a well running engine should behave, if it's smoky or the cap is bouncing remove the breather pipe too and if the smoke is coming there the problem is not with the catch can but with the engine

My td5 blow by - YouTube

I removed the filter from the Provent, the smoke stopped.

Originally Posted by Bohica

I removed the filter from the Provent, the smoke stopped.

If the factory depression control valve is not installed you will have full time crankcase ventilation - however the filters do get clogged - you’ll get 20,000 to 40,000 km out of a filter. I have successfully washed one in degreaser BUT dry them thoroughly in the sun for before re-installing them. I have two - 1 in service and a washed or new one ready to go in. I expect that washing them would eventually degrade them so I do have a new one on hand.

Originally Posted by onebob

If the factory depression control valve is not installed you will have full time crankcase ventilation...

Does it? The ProVent 200 has it's own built in PCV.


I seem to recall that the new genuine filters for the ProVent 200 were rather expensive. I fitted one of the aftermarket metal reusable filters. I've also got my drain tube plumbed into the turbo's drain pipe (with a one-way valve fitted). it seems to just be happy to be left alone to do it's thing when set this way. Sure, it might not be filtering as effectively as a genuine setup but it's still a step up above no ProVent 200 and the almost maintenance free approach is nice.

I dont really understand the utility of these provent things as long as the engine is running well other than profit for those who sell them... all i know is that a friend of mine fitted one and while without it the oil filler cap behaved normally like in the video i posted after that provent was fitted the cap started bouncing and the blow by was visible, then he binned it and it was well agai... si IMO it's just an expensive downgrade with a good advertising. On a well running engine the crankcase gasses would not "contaminate" anything too much, cleaning the intercooler after a time is a good move anyway. If there is excesssive crankcase gas a filter is not the cure. Even though i liked the ideea at the beginning after i understood better how the Td5 works i'd not fit such thing on mine ever...nor seem to need it.

Originally Posted by sierrafery

I dont really understand the utility of these provent things as long as the engine is running well other than profit for those who sell them... all i know is that a friend of mine fitted one and while without it the oil filler cap behaved normally like in the video i posted after that provent was fitted the cap started bouncing and the blow by was visible, then he binned it and it was well agai... si IMO it's just an expensive downgrade with a good advertising. On a well running engine the crankcase gasses would not "contaminate" anything too much, cleaning the intercooler after a time is a good move anyway. If there is excesssive crankcase gas a filter is not the cure. Even though i liked the ideea at the beginning after i understood better how the Td5 works i'd not fit such thing on mine ever...nor seem to need it.

I guess that the trouble is a TD5 might run fine for another 250k km after there is some noticeable blow by, and with minimal reduction in performance and fuel use.

But whilst running fine they will put oil vapour through the entire inlet including the intercooler, reducing efficiency somewhat.

I run them on mine, they do make a considerable difference, and you'll be surprised how much vapour a completely healthy one will put out when running for extended periods at 100-105°ect in 45-50°ambient.

In fact most will have visible blow by in these conditions.

There was a crew in Australia that did a mod on the "rocker cover" filtration system that's built in, by all reports it did help.

Originally Posted by sierrafery

I dont really understand the utility of these provent things as long as the engine is running well other than profit for those who sell them... all i know is that a friend of mine fitted one and while without it the oil filler cap behaved normally like in the video i posted after that provent was fitted the cap started bouncing and the blow by was visible, then he binned it and it was well agai... si IMO it's just an expensive downgrade with a good advertising. On a well running engine the crankcase gasses would not "contaminate" anything too much, cleaning the intercooler after a time is a good move anyway. If there is excesssive crankcase gas a filter is not the cure. Even though i liked the ideea at the beginning after i understood better how the Td5 works i'd not fit such thing on mine ever...nor seem to need it.

The Provent catches the oil vapour that would otherwise condense in the intercooler . I got half a cup of oil out of my Td5 intercooler before adding a provent. The issue is the Oil continues into the inlet manifold & mixes with EGR carbon (if you still have EGR fitted) & turns into a sticky carbon paste that makes a mess inside inlet manifold that is not a good thing either.

Originally Posted by goingbush

The Provent catches the oil vapour that would otherwise condense in the intercooler ..

While it mixes up the whole crankcase breather system.... as i reported... i'd better clean the intercooler once in let's say 2 years rather than creating artificial blow by with that additional filter... make that test with the oil filler cap then think twice.... but that's just me, no offence