Provent filter (newish) resulting in extra crankcase pressure and potential oil leaks

[feraldisco]

Hi, there's been a bit of publicity about this lately on youtube so I thought I'd do the oil filler cap test with hot Td5 engine idling and with and without provent filter inserted. Even though the filter is reasonably new, it definitely results in more pressure in the crank case with filler cap rising, while without provent filter in place the filler cap remains seated. This differential in pressure must get even worse as revs/load rises. I realise D2 Td5s leak a fair bit regardless, but I'm wondering how much this extra pressure is contributing to oil leaks. I'm about to replace my rocker cover gasket to stem the flow a bit but am wondering if I should now just vent the crankcase straight to atmosphere HQ Holden style, or if I could keep my provent setup in place but without a filter, and just accept that I'll be cleaning my intercooler now and then? Thoughts?

[sierrafery]

What i know is that higher crankcase pressure leads to higher engine temperature too eventually overheating... IMHO those provent things are wasted money, more advertising than benefits... if the engine is well maintained and faultless the blow-by gas should be neglectable and the original setup with the DCV is good enough, the rocker cover has it's own oil separator for that. When i fitted the larger intercooler the 10 years old original was not so contaminated to be scared at all. I'd not fit such provent even if it was free.

[Tins]

Mt TD5 has done about 350k and the blow by and leaks are quite minimal. My 220K Barra is worse.

[PhilipA]

I think there are two things that cause excessive crankcase pressure.
1 the filter in the Provent is blocked.
2 you have 2 manifold depression valves if you keep the original. I removed the crankcase depression valve in my copy Provent.
whoops 3 it is plumbed incorrectly with the input to the output.

i could add 4 I suppose that it is too small for the application , but I have a Provent 150 copy and it seems great. I also have a stainless mesh filter which seems to work pretty well as my inlet manifold is quite dry. (TD5 230KK)
I get a couple of teaspoons full of oil out the drain every say 7000Km.
Regards PhilipA

[feraldisco]

I think there are two things that cause excessive crankcase pressure.
1 the filter in the Provent is blocked.
2 you have 2 manifold depression valves if you keep the original. I removed the crankcase depression valve in my copy Provent.
whoops 3 it is plumbed incorrectly with the input to the output.

i could add 4 I suppose that it is too small for the application , but I have a Provent 150 copy and it seems great. I also have a stainless mesh filter which seems to work pretty well as my inlet manifold is quite dry. (TD5 230KK)
I get a couple of teaspoons full of oil out the drain every say 7000Km.
Regards PhilipA

Yeah, I think the stainless mesh filter might be the go...intercepts oil vapour but not too restrictive...I used to use one and think I'll return to it... My Disco has always 'breathed heavily'...possibly a function of previous owner not sorting out the poorly sealed airbox and living on a dirt road for the first 140K km of its life!

[onebob]

Yeah, I think the stainless mesh filter might be the go...intercepts oil vapour but not too restrictive...I used to use one and think I'll return to it... My Disco has always 'breathed heavily'...possibly a function of previous owner not sorting out the poorly sealed airbox and living on a dirt road for the first 140K km of its life!

Another, and not uncommon thing that can lead to increased crank case pressure is - failing turbo oil seals. If that is the case exhaust gas can enter into the turbo oil feed return drain and pressurise the crankcase. Indications that this might be happening is a show of oil between turbo and manifold (that is not from a banjo bolt leak) plus turbo shaft end play. To check the turbo shaft end play remove the airbox hose and the turbo front cover to access the turbine wheel- there should be no side to side or in/out movement and the turbine wheel should be bright and clean and not soiled as shown in a following pic.
https://uploads.tapatalk-cdn.com/20230609/b27251df04074ee3e4f0d548c5929c5c.jpghttps://uploads.tapatalk-cdn.com/20230609/2771df075823b3df74d747311521ae0d.jpg

[Bohica]

I only have the valveo n the Provent. I remove about 300mL of oil every three months. That is crap that goes into the inter cooler. No removal anmd clean the inter cooler every 2 years required. It will need a clean in about 350K km. About 17 years. By then the engine will have done about 650k km.

[laney]

What is a valveo I have a steel mesh filter in my provent 200 not sure if the steel mesh filter is the way to go but thought I would give it a go the original filters are getting to expensive if any one has any experience with the steel mesh filters I would like to hear your thoughts.
Thanks Phil

[AK83]

What is a valveo ....
I took that section of Bohicas' reply as "valve on the ..." and not "valveo n the ..."

ie. and case of fumbled fingers!

As for the mesh filter vs cloth filter. I'd say that you're really filtering the oil, but trying to minimise the amount of oil back through to the intake.
If the mesh filter you are using is not allowing oil mist build up in the intake, then it works.