Maverik Posted August 11, 2020 Author Share Posted August 11, 2020 Just thinking about the actual function of that valve - I think its there to protect the engine from having the turbo "suck" the crank case directly, i.e. as soon as you get a hint of negative pressure it pulls closed to its generally stopping the turbo from negatively pressuring the crank case, i.e. it will only really work like it should on nice "air tight" new engines, if there are air leak paths (pistons included) then you will never pull a vacuum on the crank case so it wont ever shut... unless you're sucking really hard I guess. Quote Link to comment Share on other sites More sharing options...
Sigi_H Posted August 12, 2020 Share Posted August 12, 2020 You are right. The wool is in pre Tdi. The diaphragm in the other one is to prevent the engine from rebreathing. This generates a slight vacuum in the engine case as well. More important in my eyes is, that you can easily see, that the breather forms a cyclone. At the bottom of the breather centrifuged oil is feed back to the engine. Each catch tank from metal and a bit bigger will do that better, beside having a diaphragm. 1 Quote Link to comment Share on other sites More sharing options...
Sigi_H Posted August 12, 2020 Share Posted August 12, 2020 As an example: In Formula1 the engines are not only evacuated with vacuum pumps, but the cranks are constructed in streamline too. The air in the crank case is responsible for quite big losses. Vacuum in the crank case is preferred, not only in Formula1 😉 1 Quote Link to comment Share on other sites More sharing options...
monkie Posted August 12, 2020 Share Posted August 12, 2020 On 8/11/2020 at 11:51 AM, Maverik said: Just thinking about the actual function of that valve - I think its there to protect the engine from having the turbo "suck" the crank case directly, i.e. as soon as you get a hint of negative pressure it pulls closed to its generally stopping the turbo from negatively pressuring the crank case, i.e. it will only really work like it should on nice "air tight" new engines, if there are air leak paths (pistons included) then you will never pull a vacuum on the crank case so it wont ever shut... unless you're sucking really hard I guess. The breather system modification that was fitted to the NA engines had a valve too, so it can't be because of the turbo 1 Quote Link to comment Share on other sites More sharing options...
Mo Murphy Posted August 12, 2020 Share Posted August 12, 2020 Mav, My experience of removing the breather to the air box to a catch can was negative with an increase in general minor oil seepage/leaks. These all without exception resolved on refitting the the breather hose to the air box. I can only assume that it does create an amount of negative pressure in the crankcase which helps keep the oil in. I'm no expert but keeping oil inside seemed better to me 😉 So I just live with the dollop of oil in the air box at filter change time, which I'm sure stops the inside of the box rusting 🤣 Mo 1 Quote Link to comment Share on other sites More sharing options...
Snagger Posted August 12, 2020 Share Posted August 12, 2020 That’s why they vent to the intake, rather than catch cans - the slight negative pressure (not a vacuum, and “slight vacuum” is an oxymoron) means small amounts of air will leak into the engine through any weak seals or gaskets, it out. Unless the engine is breathing heavily, you should lose much less oil through the breather system than you would through leaks. The Mann breathers seem to have a good reputation for good breathing and trapping all the oil, but for near £100 prices, they should be good! 1 Quote Link to comment Share on other sites More sharing options...
Sigi_H Posted August 12, 2020 Share Posted August 12, 2020 There are several aspects: Oil tightnes => connection to the air box => vacuum Thrown and blown oil => cyclone separator with recirculation of liquid oil Environment => no catch tank with open vent => connection to the air box => oil vapour is burned Background is an engine needs to breathe, because the pistons produce oscillating air columns in the crank case and blowby gases 1 Quote Link to comment Share on other sites More sharing options...
Maverik Posted August 19, 2020 Author Share Posted August 19, 2020 So the later 200's and the 300tdi had the extra breather plate and hosen going up to the rocker cover just forward of the cyclone breather... as my S suffix is early it doesn't have that breather, I was trying to figure out why it was installed, and if it was worth me putting in... I can only assume it allows an more unrestricted vent path from the crank case to the rocker cover rather than up the oil drain ways etc... Quote Link to comment Share on other sites More sharing options...
Gluv Posted August 19, 2020 Share Posted August 19, 2020 On 8/12/2020 at 3:48 PM, Snagger said: That’s why they vent to the intake, rather than catch cans - the slight negative pressure (not a vacuum, and “slight vacuum” is an oxymoron) means small amounts of air will leak into the engine through any weak seals or gaskets, it out. Unless the engine is breathing heavily, you should lose much less oil through the breather system than you would through leaks. The Mann breathers seem to have a good reputation for good breathing and trapping all the oil, but for near £100 prices, they should be good! I've fitted a provent to my 300 tdi . No problems so far. It certainly stops the oil in the intake Gluv🇬🇧 Quote Link to comment Share on other sites More sharing options...
Maverik Posted August 19, 2020 Author Share Posted August 19, 2020 1 hour ago, Gluv said: I've fitted a provent to my 300 tdi . No problems so far. It certainly stops the oil in the intake Gluv🇬🇧 You got any photos of your installation? Quote Link to comment Share on other sites More sharing options...
western Posted August 19, 2020 Share Posted August 19, 2020 My 200tdi only has the cyclonic breather to the air cleaner casing, the forward cam follower cover is a blank plate, no other pipes to vent the crankcase, my engine was fitted in 1994 brand new as one of the re-power kits, I haven;t got a problem with excess oil in the air cleaner,I just wipe it out at every filter change. I noticed on a mates Td5 that they have the valve housing [the top section of the tdi breather] on the intake pipes as well. Quote Link to comment Share on other sites More sharing options...
Gluv Posted August 19, 2020 Share Posted August 19, 2020 42 minutes ago, Maverik said: You got any photos of your installation? Just a couple , not the best ! . I struggled to fit it in mt engine bay due to the filter box and webasto and pipe work Quote Link to comment Share on other sites More sharing options...
Mo Murphy Posted August 20, 2020 Share Posted August 20, 2020 I have the connecting hose between rocker cover and crankcase. I assume it's to allow pressure equalization. No idea what age mine is though. Mo Quote Link to comment Share on other sites More sharing options...
Maverik Posted August 20, 2020 Author Share Posted August 20, 2020 9 hours ago, Gluv said: Just a couple , not the best ! . I struggled to fit it in mt engine bay due to the filter box and webasto and pipe work Perfect thanks, I actually also found another set of posts where you talk about your installation. I've just found a ProVent 100, cheap on fleabay, they are rated up to 100kw and 100l/m flow going to have a look at what I can do with that I think. Quote Link to comment Share on other sites More sharing options...
Maverik Posted September 1, 2020 Author Share Posted September 1, 2020 So next plan is to fit this wee beauty... Going to attempt to mount it in the same place as the standard place... Quote Link to comment Share on other sites More sharing options...
Peaklander Posted September 1, 2020 Share Posted September 1, 2020 OO that looks interesting. It has a serviceable top. Hope it fits. Quote Link to comment Share on other sites More sharing options...
Maverik Posted September 1, 2020 Author Share Posted September 1, 2020 Just now, Peaklander said: OO that looks interesting. It has a serviceable top. Hope it fits. Its I think a copy of a Mann ProVent 100 as its pretty much identical but doesn't have any part numbers on it, certainly wasn't expensive as a MANN version. - there are a couple of challenges for me to look at, but I think I'll manage to make it fit. 1 Quote Link to comment Share on other sites More sharing options...
Maverik Posted September 1, 2020 Author Share Posted September 1, 2020 So went down the mix and match route... looks good but glue is rubbish so ripped itself apart when I installed it. Back to the drawing board. Quote Link to comment Share on other sites More sharing options...
Gluv Posted September 1, 2020 Share Posted September 1, 2020 30 minutes ago, Maverik said: So went down the mix and match route... looks good but glue is rubbish so ripped itself apart when I installed it. Back to the drawing board. You're better off buying brass pipe adapters off eBay and some oversized oil pipe to fit on the provent . Mine was a pain adapting from the 1" on the provent 200 . Anything else will just leak ....ask me how I know ! Provents are definitely worth the hassle of fitting 👍 Quote Link to comment Share on other sites More sharing options...
Gluv Posted September 1, 2020 Share Posted September 1, 2020 Ooh , just noticed the bottom is busted ! 😳 Gluv🇬🇧 Quote Link to comment Share on other sites More sharing options...
Maverik Posted September 1, 2020 Author Share Posted September 1, 2020 6 minutes ago, Gluv said: Ooh , just noticed the bottom is busted ! 😳 Gluv🇬🇧 Not busted - modified... Quote Link to comment Share on other sites More sharing options...
Gluv Posted September 1, 2020 Share Posted September 1, 2020 3 minutes ago, Maverik said: Not busted - modified... Oh I honestly think you will have more joy mounting it remotely Gluv🇬🇧 Quote Link to comment Share on other sites More sharing options...
Sigi_H Posted September 2, 2020 Share Posted September 2, 2020 I found the problem. These hands are too clean ... Quote Link to comment Share on other sites More sharing options...
Mo Murphy Posted September 2, 2020 Share Posted September 2, 2020 ... and you're wearing sandals. Proper protective footwear is essential to get these seperators to work properly. HTH Mo Quote Link to comment Share on other sites More sharing options...
Davidpaul Posted September 2, 2020 Share Posted September 2, 2020 On 8/7/2020 at 12:25 PM, Maverik said: As title suggests, I've recently noticed since installing the VGT turbo to my aged 200tdi, that there's a little more oil pull through into the air filter housing as per the standard factory set-up - I used to get some oil in the filter can top section with the original turbo, but since the normal operating inlet pressure is a fair bit higher now +1bar, I think it must be dragging more through from the crank case, I replaced the breather pot with the Ali sports one which hasn't helped either. Short term I've just put the breather air outlet into a bottle with a perforated top section, and I had a mind of just installing a catch tank - So having a bit of time to mull the problem over, I was thinking that the increased air flow from the higher inlet pressure was actually pulling the oil ladened blow by gas through the cyclone before it got chance to separate out.... so why not slow it down? - so then though why not just put an orifice into the breather gas/air pipe at the filter end... anyone any thoughts? Mav Can I ask what turbo you used please, i have a vgt here but i haven't fitted it yet, was there much improvement low down ? Quote Link to comment Share on other sites More sharing options...
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