Time for a long-overdue update. My car had a couple of issues I wanted to sort out. First was poor crankcase evacuation. The ATW engine is one of the few variants of the 1.8t that did not have a breather attachment on the valve cover; only relying on a block-mounted PCV breather box. This would cause blowby to come out of the dipstick tube due to oil windage blocking the PCV system vent with oil. (at high boost)
The second issue was airflow to my MAF. I had a short 90° elbow in front of it causing turbulence at the MAF. To solve issue #1, I needed to send excess crankcase air into the intake system to be re-burned.
I purchased a used valve cover from eBay that has a 19mm breather attachment. To keep as much oil out of the intake as possible, I added a catch can. I already had an air pump pulling air from the PCV system and dumping it into the exhaust, post turbo. This never worked well due to windage. This did however place oil into the exhaust tubing and would drip a little at a V-band clamp after a long drive. The air pump is from a VW (smog pump) repurposed and controlled by a 3psi pressure switch. Once it goes into boost above 3psi, the pump pulls air from the top of the valve cover and PCV box, pushing it to the air cleaner.
I purchased a bulkhead fitting for installation on a silicone boot in from of the MAF. Introducing more turbulence into the stream. The MAF is located right next to the passenger side firewall, near the old battery tray location. A hole into the fender cavity provides cold air via a NACA duct. I used a longer fitting before the MAF to allow straight air to be metered. The PCV air enters closer to the air cleaner (also inside the fender)
So before when I drove and hit high extended boost, the cabin would fill up with smoke and it would look like I blew an oil line behind me. Very embarrassing and unsightly.
Now there is zero smoke and the MAF work has resulted in increased torque at low rpm that is scary. Way scary! and fun!!!
Old valve cover, no breather tube.
Click to view attachmentNew valve cover in place. catch can on left, air pump on right. You can also see the 3psi switch on the right.
Click to view attachmentClick to view attachmentI had to clearance out the NACA duct due to the added length from the MAF. What you see cut out actually sits out proud from the NACA by 3/8".
Click to view attachmentThe third problem, I could not get the valve cover off without dropping the engine. A couple of cuts solved this too. The top right, under the blue boot, is the MAF. the blue boot is recirculated air from the combo recirc/blowoff valve. It reintroduces air right after the MAF since this air was already metered by the MAF. Crankcase air is unmetered and must be introduced before the MAF. It's also full of atomized oil droplets. This is what the catch can is for, pulling large droplets out of the air stream.
Click to view attachment