The inside of my ‘95 TSi AWD’s air intake is often coated in oil and the source is the 6mm I.D. rubber hose from the non-PCV vent on the valve cover. This oil catch can was built to prevent this oil build-up and cost less than CAN$50 using commonly available air compressor filter & parts.
Parts needed:
3 – Zap straps 10”
1 – Porter Cable 3/8” filter assembly
2 – 3/8” hose repair kits
6’ – Silicone hose 6mm I.D.
4” – Silicone hose 8mm I.D.
Teflon tape – oil & gas compatible
Parts notes:
I could have used 4” or 6” Zaps, but didn’t like how narrow they were. I used 10” Zaps because I liked how thick they were and felt the air compressor filter (filter) mounting would be secure.
The filter and two 3/8” barb kits just happened to be on sale the day I stopped by the local Sears. <Pictures CCan Parts I to III>
The filter is 6 1/2” long by 5 1/2” wide, made of a die cast metal and weighs about 2.5lbs. I like the sight glass (shows as a silver, vertical line on the filter’s catch basin) that lets me know how much oil is the catch basin. <Pictures CCan Dimension I & II, CCan Temp Rating, CCan Sight Glass>
The lengths of silicone hose will vary to suit your tastes and preferred location. I got the hose from Road Race Engineering.
Teflon tape is from Home Depot. The tape used is rated for oil & gas. The usual plumber’s Teflon tape is rated for water connections. This goes onto the hose barb’s threads before screwing them into the filter’s body. <<Pictures CCan Parts IV & V>
Tools needed/suggested:
Drill
1/4" drill bit
Wire cutters to cut zap straps
Scissors or knife to cut silicone hose
Black felt marker to mark where you’re going to drill
Jack and safety stands
safety goggles
Installation:
Set the E-brake, block both rear wheels, jack up the car, place both safety stands, put on your safety glasses (keep the under car crud from falling into your eyes) and call your Mom on her birthday.
Gravity is good and can help you. I kept the filter down low, lower than both the valve cover and the air intake as I wanted any oil vapour in the lines to drain down into the filter’s catch basin when the engine is OFF. The filter is not, in my opinion, a show piece.
I chose a spot just inside of the passenger front wheel to mount the filter and marked the filter’s fitment. I drilled 5 holes into the plastic inner fender material. I chose to hold the weight of the filter by its two 3/8” barbs on either side of the filter. To keep the filter’s bottom from flapping towards the engine, the drain valve’s housing at the bottom is Zapped too. Yes, that is the stock side mount intercooler’s intake in the picture. <Pictures CCan Zap Mount & CCan Pre-Mount & CCan Silicone Hose Attached>
There’s a short length of 8mm I.D. silicone hose on the end of the filter to help empty oil into a container. <Pictures CCan Finished>
Comments:
Looking from the top of the engine bay, you would never see the filter.
So far, I have put 1,600Km (1,000 miles) on the filter. Idle speed did not change (with the stock MAF/air intake). The hoses have not separated from the filter, valve cover or air intake. The three Zap straps kept the filter in place. There was no oil in the filter to drain out either.
To drain the filter, you could reach under and feel around to open the filter’s drain valve. Valve is shown open below <Pictures CCan Pre-Mount>
and closed below <Pictures CCan Silicone Hose Attached>.
I prefer to jack the car up to get at the drain valve while doing my other under car maintenance. This way I can also be sure that the valve is closed as dirty air would be sucked in past an open drain valve, so beware.
I’ll update this post with anything that turns up; it’s work in progress that I’ll monitor.
Update 25 Sept 2009:
It has been 2 months and 3,450Kms (2,155 miles) since the filter was installed. There was a run for the FVT 2009 and a run up to Campbell River, BC (lucky Van Island BC DSMers!) during that time.
Still, there is no oil or sludge in the filter. The sight glass is still clear and when the drain cock was left open for half an hour, nothing dripped out of the hose. The filter's body has no visible cracks on its exterior, is still securely held by the Zaps and the silicone hoses have not moved off their barb fittings.
I am guessing there is some blow-by going between the VC and the filter because I can see an oil "sweat" covering the hose's exterior that attaches to the VC barb. The sweat covers 3" of the hose. The sweat beads never joined to form oil droplets (my condominium's strata bylaws probably scared the beads into not forming oil drips onto the concrete flooring of the parking spot).
