Mann-Hummel CCV drain - to sump?

Messages
2
Location
NY, USA
Hi all, First time posting (hello!) and I’m not sure if I’m posting in the right area, but hopefully I am. So here goes: I have a 2012 VW Golf R that is fairly modified. Engine wise the main bits are stock, but pretty much all bolt ones available have been added. Now with the tune that I have boost is nearly doubled, 17.5psi max to about 30-32psi depending on the restriction in the plumbing, and engine output is also essentially doubled. Having taken apart the bits many times for various maintenance I got sick of having a good amount of oil in the plumbing and could tell the catch can I had was doing a horrible job (basically fought nothing in the warmer months). I considered putting marbles or steel wool in it to increase surface area, but said screw it and went with a proper CCV system used as an OEM for diesel motors: the Mann Hummel ProVent. Having installed it I’m thrilled that I have - a solid amount of blow by fluids is captured even in the summer months. But this now opens up a new question: the provent has a drain and is designed to drain back to the sump (with instructions covering multiple setups to the sump), however I’m sure that when used as a stock component the provent is probably mounted close/on the block - thus getting much hotter which I would think would minimize the amount of water in the run off fluid. Now currently in the summer the fluid captured isn’t milky, it’s black, but it does seem to have water in it based on the viscosity and seeing some water droplets in the hose. So my question: is it ok/Safe to plumb this back down to the sump? The total volume isn’t huge, but you don’t really want water in the oil and I have yet to see what the discharge looks like in the winter. I wish I could mount it closer to the motor, but I don’t have the space. At the moment there is about a foot+ of hose coming from the cylinder head to the provent (which is mounted behind the passenger headlamp) and then there would be hose going down to the sump (my guess is if I did that it would be about 3 feet). That’s a good amount of extra surface area to cool down any fluids, although I could use heat wrap to keep heat in? I have sent a query out to blackstone to see what they think/if they want a sample, but it’s a rea PITA to drain the hose regularly. The small amount of hose I have on right now (while I’ve been working on fabricating a permanent location for the provent & then a permanent drain hose) fills up super fast. About 4-5” of 1/2” hose fills up in 100 miles. I could add more hose and use a stopcock (such as those found on air compressors) as I originally planned, but using some simple math that would only give me like 600 miles in the summer....probably less in the winter. I could try to make a little reservoir to collect the fluid, but that’s more fabrication & I would need to figure out a way to drain that....and I don’t exactly have the equipment to make that stuff with ease. When I put something together I have to search for similar parts on the internet and modify for my use (don’t want to pay the 1k+ it would cost to have a shop make it since this is a pretty simple thing and it’s not worth that much to me). In addition I have divorced the oil and water cooling systems and added an air to oil cooler (between the radiator and ac condenser, where the stock intercooler was) with a thermostat. But the oil isn’t brought to temp quite as quickly as it was previously, I would think, especially since the oil thermostats never fully close...just partially close. So for short drives I could have lower than normal oil temps. So gentlemen, do we think the fluids captured from the coalescing filter in the provent are safe to return to the sump? Or are they not? They are after all the result of what is picked up by blow by from the sump.... Oh and I would be routing the drain to either the turbo oil drain or, if fitting the adapter could somehow kink the turbo waste oil pipe, to an extended oil drain plug with a banjo fitting. Point being is that I wouldn’t be using a check valve as the drain would be below the top of the oil level. Hopefully this helps since it wouldn’t be dumped in after the engine stops (meaning it would be drained while it’s on increasing the likelihood for that oil/discharge to be brought up to temp). Cheers!
 
Last edited:
Messages
6,765
Location
Fort Lauderdale, FL
There are plenty of CCV systems in OEM applications that drain back to the sump. That moisture is coming out of the engine in the first place. It going immediately back to where it came from will not hurt anything. Keep in mind that the amount of moisture going back will be small and continuous, and eventually will be boiled off. There will be no "load" of moisture going back. That arrangement is not 100% efficient at coalescing water vapor. It will eventually boil off and be sucked into the engine intake. Run it as instructed and plumb it back to the engine in appropriate manner.
 
Messages
2,016
Location
Crawfordville FL
Originally Posted By: DoubleWasp
There are plenty of CCV systems in OEM applications that drain back to the sump. That moisture is coming out of the engine in the first place. It going immediately back to where it came from will not hurt anything. Keep in mind that the amount of moisture going back will be small and continuous, and eventually will be boiled off. There will be no "load" of moisture going back. That arrangement is not 100% efficient at coalescing water vapor. It will eventually boil off and be sucked into the engine intake. Run it as instructed and plumb it back to the engine in appropriate manner.
+1 It will be evaporated out of the oil once it warms a bit,
 

appoli

Thread starter
Messages
2
Location
NY, USA
Thanks guys, much appreciated! I was under the same impression, but people had been telling me that going back to the sump may be a bad idea (including my mechanic, well recently former mechanic so I take a lot less stock in what he says now...and he originally told me the provent would have been useless, but he was originally a scientist before he became a tuner, specifically a chemist) so I have been apprehensive. But this is music to my ears! Haha. I have been thinking of ways of fitting a can below as a holding tank. And yea I know that the water in the gasses wouldn’t be crazy and without a check valve would be added in relatively small quantities , but I also don’t want to hurt ‘my baby’. And yea I know that the stock system runs back to the sump, but I know the secondary CCV system uses a cyclonic (or whatever it’s called) separation method, not sure about the primary. The effeciency regarding how well coalescing filters pull out water was basically what I was looking for. Many thanks guys!! And I would like to hear from others that are running a provent - curious how much their setup collects. I was surprised as to how much more it pulls than a catch can (even though I know the PCV setup on my car is known to be extremely poor & an adequate catch can would have needed a lot more surface area/baffling). I showed the blow by to a tech at the shop that was doing my corner balance & his first response was “your rings are shot” but that was based on what he’s seen a catch can collect.
 
Top