Filtering Blowby

[moribundman]

If one were to filter PCV blowby in the 0.01-3.0 micron range, in what shape would the filtered oil be?

 

[JAG]

It is an odd thing but PCV system contents in my VW 1.8T engine has proven to be very problematic since the contents are superfluous and fouling/clogging in nature. I had to replace the system once already which cost $500 in parts and labor so it is a costly matter. Our Infiniti on the other hand has no such issues.

For the VW I have been trying to figure out how to best prevent PCV clogging in the future. Certain oils, certain OCIs, keeping engine bay temps high enough to evaporate the water contents in the PCV system, and oil consumption rate, are what's on my mind. With my new PCV system it is still getting fouled up with short OCIs and Mobil 1 0W-40 which has low volatility so that will increase the blowby to oil vapor ratio which may be bad. Maybe higher volatility oil would help. Your question may be related. My answer to it is that if you filtered the blowby in that size range you'd get an oil/water emulsion that also has nasty combustion products in it. It would be in bad shape chemically (much worse than the sump oil) in my opinion due to those chemicals which are very reactive. Why do you ask?

 

[tom slick]

I don't know what condition the oil would be in but the water and fuel vapor that collected with it wouldn't encourage me to reuse it.

 

[dwendt44]

I've heard of some folks installing a 'catch can' in the PCV system.
Sounds interesting, especially if oil is being sucked into the valve and throttle body.
I have no details though.

 

[moribundman]

Originally Posted By: JAG
It is an odd thing but PCV system contents in my VW 1.8T engine has proven to be very problematic since the contents are superfluous and fouling/clogging in nature. I had to replace the system once already which cost $500 in parts and labor so it is a costly matter. Our Infiniti on the other hand has no such issues.

For the VW I have been trying to figure out how to best prevent PCV clogging in the future. Certain oils, certain OCIs, keeping engine bay temps high enough to evaporate the water contents in the PCV system, and oil consumption rate, are what's on my mind. With my new PCV system it is still getting fouled up with short OCIs and Mobil 1 0W-40 which has low volatility so that will increase the blowby to oil vapor ratio which may be bad. Maybe higher volatility oil would help. Your question may be related. My answer to it is that if you filtered the blowby in that size range you'd get an oil/water emulsion that also has nasty combustion products in it. It would be in bad shape chemically (much worse than the sump oil) in my opinion due to those chemicals which are very reactive. Why do you ask?



Check your PMs.