Thread: Pommie Provent

What I'm pointing toward is that it's not an on/off scenario, there are likely times that as crankcase pressure builds (due to the closed PCV), that the pressure would become sufficient to cancel out the boost and allow it to open again. But again, this is based on deduction. Would also like to learn more from others.

Hi there,
when you plumb in your Provent swap the connections round so that oily air from the rocker cover goes in the lower hole and clean air to the intake hose comes out of the upper hole.

I have a breathey 200Tdi and so fitted a Provent the way you have. I had problems with oil blowing out of the filler cap due to the filter in the Provent becoming blocked and oil in the air filter housing. The blow off valve on the body of the Provent did nothing because it was on the wrong side of the blocked filter.

I cleaned the filter, swapped the connections and haven't had a problem since.

If you think about it a filter is meant to have a dirty side and a clean side, an air filter has an air/dirt side and a clean air side. The provent should have an air/oil mist side (from the rocker cover) and a clean air side (to the air intake hose). The way you have it connected oily air goes in the top and clean air is sucked out the bottom to the intake. However the oil filtered out has to migrate through the filter media to drip down into the bottom of the unit to the drain.

If the oil/air mist goes in the bottom the oil is caught on the filter and then drips down to the drain whilst clean air is sucked out of the top. Also if/when the filter becomes blocked and pressure builds up in the bottom of the Provent the blow off valve will operate.

When I had my oil problems there was oil pooled in the air filter housing which should have been filtered out by my Provent so I thought it was worn oil seals on the turbo so I went to a Turbo place to have it checked out - it was he that pointed out that the filter was connected wrongly. As a chemist who has done a lot of filtering in my time I was quite embarrassed! The turbo, to my relief, was declared fit and healthy.

Here's a link to pictures of my original Provent installation - the connections are now swapped!!
https://www.flickr.com/photos/andyro...57626644610817

Andy

Hmm, I see what you are saying but surely in your setup the oil will be sucked into the centre of the filter and pool there rather than dripping off into the pickup?

Hi there,
the simple answer is "no" - the way you currently have it set up the oil pools in the centre of the filter and blocks it. When the engine is off the oil has to soak through the filter to drop down into the drain which obviously blocks the filter.

Originally Posted by AndyK

Hi there,
the simple answer is "no" - the way you currently have it set up the oil pools in the centre of the filter and blocks it. When the engine is off the oil has to soak through the filter to drop down into the drain which obviously blocks the filter.

I don't agree with your reasoning there mate, going to stick with the manufacturers instructed setup.

Originally Posted by AndyK

...I had problems with oil blowing out of the filler cap due to the filter in the Provent becoming blocked and oil in the air filter housing. The blow off valve on the body of the Provent did nothing because it was on the wrong side of the blocked filter....

Sorry there is some misunderstanding here.

The oil blowing out the cap means the pressure relief valve in the cap is doing its job. The pressure drop across the filter has reached >50 mBar and the relief valve is venting to atmosphere so you don't run the risk of blowing any oil seals.

The valve in (what is intended to be) the outlet is there to block the flow if the pressure in the intake becomes too low. If you are swapping the inlet and outlet around you should remove or disable this valve.

For anyone who hasn't bought one yet, IMHO the Provent 400 is a better design if you can fit one in, plus, some worked TD5s and newer may be putting out more than the 200 kW the PV200 is designed for.. However, hundreds of thousands of people around the world are running the PV200 as designed with no problems.

From:
"https://www.mann-hummel.com/fileadmin/user_upload/service/catalogues/pdf/ProVent_en_2013.pdf"
"The ProVent 200 is a compact crankcase ventilation system for engines up to
250 kW and is characterised by the following advantages:
? Up to 200 l/min blow-by gas"

Pitty its such a monstosity of a thing, very limited with places to fit, and keep it neat, and get it draining back to sump.
Its a shame the PV150 isnt upto the task as its a little more compact.