Anyone ever tried to modify/simplify the PCV system?

[howardc64]

Been toying around with a 01 VW Golf with 1.8T (turbo) engine. This car has quite a complex emissions system. Anyhow, these cars attracts a lot of tuners+mods and they've figured out how to simplify the PCV system on this car. Making it healthier. Was just wondering if anyone has done PCV system mods on these P2s?

The mod would basically be like this

Instead of an oil trap that filters out all the oil+gas vapor in the blowby and dumps it back into the engine oil, run it to a catch can and remove this undesirable mixture from the engine all together. A catch can basically serves the same purpose as a oil trap but provide the option of keeping the filtered blowby fluids in the can rather than dumping it back into the engine oil. Catch can can also optionally drain this liquid back into the engine block if you wish which would be exactly what the current oil trap does.

The mods would be as follows. Here is a diagram for reference

http://i.imgur.com/VboFUPN.jpg?1

- vent the blowby out of the 2 ports. One in the head (where #7 clamp goes) and the crank case PCV port (where #3 clamp goes) into a catch can. You can merge the flow with a T connection into the single inlet port of a catch can.

- You can vent the positive pressure in the catch can into atmosphere which isn't as good for the environment. Or run a hose from the PTC nipple (where clamp #12 goes) as the vacuum source for the catch can's vacuum port. This would pull the blowby air back into the intake and better for the environment. PTC nipple is basically just an open port with a heater in it. The heater prevents cold weather from icing up whatever gunk is in the port.

- probably just plug up the 2 ports fitted by the banjo nipples? the vacuum hole is so small, I can't imagine these contributes much vacuum?

- Remove the big L shaped hose (#8). Remove the oil trap (#1). Seal the oil trap drain (where #4 goes) unless you really want to run all the blowby fluid back into the engine oil. Seal the coolant port near #13 with the big L shape hose gone.

The catch can would filter and keep all the blowby mixture. You would need to periodically dump out the yucky contents.

Anyone tried this? No clogs to worry about. No blowby fluids draining back into the engine oil and keeping it cleaner longer. I hear the intake side stays cleaner. No need to clean throttle body and no oily gunk around the turbo (unless the turbo itself is leaking internally)

FYI here is what people collect in the catch can in like 1000 miles!

http://img254.imageshack.us/img254/629/img6839.jpg

[JRL]

Been done
Check on Volvospeed.com but be careful with the children over there

[Astro14]

Help me understand: to avoid the every 100,000 mile (or more) maintenance on the PCV system, you want to go to a catch can that has to be emptied of some HAZMAT gunk every 1,000 miles?

No way I would want that...I can't even get the kids to check the oil...much less empty this PITA catch can...seems like a giant leap backwards in technology...you could just vent to the atmosphere like an antique car (and completely violate the Federal regulations on emissions)...that would be easier for maintenance than this can of gunk that you're generating and collecting under the hood.

For the record, the T5 is still on its original flame trap set up...and doesn't burn or leak any oil at 151,000 miles...the XC is starting to use a bit of oil, and I am going to do the flame trap...at 173,000 miles...

How many times would I have had to empty the catch can of gunk in that 173,000 miles?

[JRL]

Guys
It's NOT called a flame trap, that went the way of the 850.

I suppose if it's YOUR car and it it's placed in a position that it can be easily dumped and reinstalled, you can save on a PCV every 100K or so. Yours IS THE EXCEPTION.
I see that catch can being cleaned every 4-5K, it's only filled 20%

[howardc64]

JRL. Thanks for the pointer to Volvo catch cans. I see tuners are doing it for bigger turbos, higher RPMs and therefore more blowby.

Astro14. Indeed emptying a catch can is an added frequent maintenance item. Certainly agree its a bit backwards towards the "maintenance free" goals that car manufacturers are striving for. Some maintenance free technologies have been great like ECUs. Some have been terrible like lifetime ATF.

I guess there just isn't a good solution to get rid of blowby. Venting part of it into intake dirties+clogs the intake. Not sure what it does to combustion. Catching the oil+fuel mixture and returning it into the engine oil is probably the main source of degradation to the engine oil quality? Anyhow, seems like no good solutions on the internal combustion engine while striving for maintenance free :(

[ifnt420]

I did a DIY write up a while back on my Oil Catch Can setup for the XC.

http://forums.swedespeed.com/showthread.php?111187

http://i116.photobucket.com/albums/o12/ifnt420/2390QB/IMG_6571Large.jpg

http://i116.photobucket.com/albums/o12/ifnt420/2390QB/IMG_6567Large.jpg

[sjonnie]

Howard, with all due respect, may I ask, what is the point of this? I understand you don't want to return contaminated oil to the crankcase but the oil and oil system is designed to cope with the contaminants and if you change with synthetic oil regularly you'll never need to do change the PCV system other than to replace worn out hoses. Or is it just to try and make those changes simpler?


vent the blowby out of the 2 ports. One in the head (where #7 clamp goes) and the crank case PCV port (where #3 clamp goes) into a catch can. You can merge the flow with a T connection into the single inlet port of a catch can.
This is the crank case ventilation, prior to the act of congress stipulating that these had to be recirculated back into the intake, they were indeed vented to the environment. Not a good thing as you point out, plus recirculating the unburnt gasses can improve fuel efficiency.


You can vent the positive pressure in the catch can into atmosphere which isn't as good for the environment. Or run a hose from the PTC nipple (where clamp #12 goes) as the vacuum source for the catch can's vacuum port. This would pull the blowby air back into the intake and better for the environment. PTC nipple is basically just an open port with a heater in it. The heater prevents cold weather from icing up whatever gunk is in the port.
Water. A significant amount of the blow by gas is water. In northern climates, simple PCV systems often get contaminated with oil-water mixes on short journeys due to water build up in the PCV system. Water oil mixes in the crankcase are very bad news and to be avoided as much as possible. The whole PCV tube from the oil separator to the intake is heated by the cooling system to prevent water condensing out and mixing with the oil. That is the purpose of the expensive 5-port tube PCV tube.


probably just plug up the 2 ports fitted by the banjo nipples? the vacuum hole is so small, I can't imagine these contributes much vacuum?
Yeah, it does (only one is a vacuum port, the other is a coolant line), at low rpm, the banjo port is the primary source of vacuum for the PCV system.


The catch can would filter and keep all the blowby mixture. You would need to periodically dump out the yucky contents.
Wouldn't it be much simpler then to block off the oil return at the bottom of the oil separator and drain the oil separator into a catch can? Again, not sure why you want to do this, yes it will keep the oil cleaner which is a good thing, but these engines can easily run 300k+ miles without a ring-job and changing synthetic oil regularly will almost certainly circumvent most PCV problems. Customizing a system that only need replacing say 3 times in the life of an engine seems like a bit of a waste of time unless there are other benefits.

[howardc64]

Howard, with all due respect, may I ask, what is the point of this?

I was mainly curious after the visceral reaction of seeing what is caught in the catch can. First reaction is "I don't want that in my engine!" But as you pointed out, regular service deals with most of this (oil change get the mixture out, periodically clean the intake side, periodically unclog various PCV hoses and ports)

Surely the catch can content is probably the best marketing tool for selling the product :)

[TheAlmightyBob]

The reason to have a catch can is to keep oil out of the intake. Seems obvious I know. But when oil vapor (and other crap) mixes with incoming air, it creates a less combustible mixture. So your computer will pull timing to keep things safe and sound. I have a Dodge Charger that I installed a catch can in, and I have data logged the timing with and without it and it does make a difference. So I don't mind emptying the can every oil change to help keep my intake clean and for a little better performance.

Someone made mention of having to empty "HAZMAT Gunk". What do you think people do with their oil after they change it themselves? Well I keep a oil bottle that I empty the contents of the can in, and it will last a good while before I have to take it with the rest of the oil change to the parts store to get rid of it. Its only 5 minutes of extra time to empty a catch can every oil change.