Provent 200

Those of you who run a Provent 200 did you keep the DCV connected as well? There is some sort of valve in the Provent but not sure if I need to keep the DCV or not if I am routing the "clean" air back to the intake?

When I fitted my Provent I just spliced it in to the existing piping so that the 'cleaned' air was still fed back in to the air intake.

Shimsteriom said:

When I fitted my Provent I just spliced it in to the existing piping so that the 'cleaned' air was still fed back in to the air intake.

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Thanks, so did you leave DCV connected as well ?

tom1979 said:

Thanks, so did you leave DCV connected as well ?

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Yes, everything was left in place.

I'd not fit such thing on a Td5, the provent's DCV is not ''calibrated'' for the Td5's crankcase pressure and it can mix up the whole crankcase breather process, you can make a simple test if you want: unscrew oil filler cap and watch the blow with provent fitted and without it and you'll see, or just watch the cap and if it's not just slightly turning then it's not OK... in 3 cases i've seen the cap was bouncing bad with provent and things got normal without it. I dont think that the excess of backpressure in the crankcase is good for the engine. I made a video with my engine which has new DCV and IMO that's how it should be, with the old DCV which wasnt stuck just ''tired'' the blow by was worst

Shimsteriom said:

When I fitted my Provent I just spliced it in to the existing piping so that the 'cleaned' air was still fed back in to the air intake.

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why did you fit it

jamesmartin said:

why did you fit it

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Probably watched too many utoob videos about the consequences of allowing oily gases to go back through the engine.

Shimsteriom said:

Probably watched too many utoob videos about the consequences of allowing oily gases to go back through the engine.

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yes to many vids selling bits,the engine has already been designed to work as it comes from the factory

jamesmartin said:

yes to many vids selling bits,the engine has already been designed to work as it comes from the factory

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But surely having cleaner air fed back in to air intake is a good thing?

Shimsteriom said:

But surely having cleaner air fed back in to air intake is a good thing?

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if it mattered it would have been fitted at the factory,td5s dont suffer from excessive oil in the inlet system, crank case pressure systems are carefully designed to suit the engine bolting stuff on isnt improving it

jamesmartin said:

if it mattered it would have been fitted at the factory,td5s dont suffer from excessive oil in the inlet system, crank case pressure systems are carefully designed to suit the engine bolting stuff on isnt improving it

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So I don't need to worry about all the oily deposits that are accumulating on the inside the intake pipes and I can only assume the intercooler?
I'm not arguing for or against them, it just makes sense to me that reducing the amount of oil going back in to the engine is a good thing.

Shimsteriom said:

So I don't need to worry about all the oily deposits that are accumulating on the inside the intake pipes and I can only assume the intercooler.
I'm not arguing for or against them, it just makes sense to me that reducing the amount of oil going back in to the engine is a good thing.

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they will be as clean as a whistle ,a wet surface is normal,only the egr needs cleaning ,your not making any useful difference, only harm if you affect the breather system

jamesmartin said:

they will be as clean as a whistle ,a wet surface is normal,only the egr needs cleaning ,your not making any useful difference, only harm if you affect the breather system

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Job for tonight then. Take the filter off

the engine has it's own oil separator so if there is excessive oil in the crankcase gas then not an external separator is the cure, as provent is not dedicated for the Td5's crankcase pressure It can mix up the system and hurt the engine IMO

Shimsteriom said:

Job for tonight then. Take the filter off

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if it has a filter yes then remove it

The reason I put one on was not because of any excess crank pressure but to filter out some more of the cr*p before it goes back into the inlet. For the last year I have had the hose on the outlet of the Provent 200 dangling down onto the chassis and the intake capped off. I can't see what harm it would do? What I wasn't sure about was whether people left the DCV in place as although the Provent has it's own it is not the same. I drained out about 200ml of horrible looking oil from the Provent the other day, which would have otherwise gone back through the intake system.

tom1979 said:

The reason I put one on was not because of any excess crank pressure but to filter out some more of the cr*p before it goes back into the inlet

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My point was that the provent creates excess of crankcase pressure not that somebody would fit one to reduce it

tom1979 said:

What I wasn't sure about was whether people left the DCV in place

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for that would be good to know how the provent's DCV works compared with the factory fitted one.

tom1979 said:

I drained out about 200ml of horrible looking oil from the Provent the other day, which would have otherwise gone back through the intake system.

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As i've seen with my own eyes 3 times the provent mixes up the crankcase breather system so the amount of oil might be the result of that. As long as the blow by at the oil filler cap is harder with provent it means there is more backpressure against the engine's oil separator system and valves so more oily gas too. IMO it's not good for the Td5 engine, believe me or not

sierrafery said:

My point was that the provent creates excess of crankcase pressure not that somebody would fit one to reduce it
for that would be good to know how the provent's DCV works compared with the factory fitted one.
As i've seen with my own eyes 3 times the provent mixes up the crankcase breather system so the amount of oil might be the result of that. As long as the blow by at the oil filler cap is harder with provent it means there is more backpressure against the engine's oil separator system and valves so more oily gas too. IMO it's not good for the Td5 engine, believe me or not

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I'm not disbelieving you! The Provent 200's get fitted a lot in Australia (no idea why) and before I fitted mine I could not find anyone who had had any problems with one fitted.

I can't find it now bot not long ago i was in a discussion on aulro about that with a guy when i made the video i posted here too and he had excessive blow by which went down after he bypassed his provent. Do that test wih the oil filler cap and if it's like in the video i posted then no worries

EDIT: i found the discussion, see the videos in these two links which are the only two relevant to show the difference not that his engine doesnt have excessive blow by anyway but i'm not convinced that it didnt end up this way in time due to the provent :
1. https://www.aulro.com/afvb/technica...by-okay-too-much-post2986910.html#post2986910
2. https://www.aulro.com/afvb/technica...by-okay-too-much-post2987171.html#post2987171


if you watch the oil cap
it's quite a difference between this with provent



and without

Interesting topic. The idea being it draws off the excess oil vapour preventing from coating the IC with oil and the rest of the system. Doesng catch a huge volume but better drained out than elsewhere.

I have a provent 200 fitted but retained the DCV. As surely the turbo induction "sucks" the vapour from the engine so the DCV is required to aid this.

Might have a play tomorroe