Last Friday’s faux blueprint image is what I gave to the Valve Store’s Tool Room guys to fabricate for me. I wanted to check what kind of oil pressure I have been getting at the top of the valve cover at the VVT’s oil control valve. I was tempted to get a kit from Harbor Freight so I could check the pressure at the spot where the car’s gauge sender sits on the block as a start. If that was good I’d figure a way to check it at the top.
Before buying I decided to query the MMC to see if anyone had one I could borrow. I got a no, a no, a maybe and a yes, but I’d need my own hose and adapter to screw into the block. The maybe turned into a no, so I went with the bare gauge option. Looking at the engine diagram I noticed that the feed for the tube running along the top of valve cover comes through a solid metal line right from the same spot as the oil gauge sender. Because that spot is not easy to get to and I would need a hose, I opted to make an adapter to hook up to the end of the valve cover inlet line.
If I had good oil pressure at the top of the engine I was done, the P0012 issue would have to then be the actuator on the end of the cam shaft or the ECU. If it was bad there, I’d get a hose and check what it was at the sender location. If the pressure was good there the problem would be in that oil line somewhere, if it was bad there I’d have big problems, like engine bearing problems. How come I didn’t just rely on the cars oil pressure gauge you ask, well because it is just basically an idiot light in the shape of a gauge. It reads in the middle of the range if there is a mere 7psi of pressure present, it should be at least twice that at idle when warm and 40 & up at 3,000 RPM.
With a cold engine the gauge was shaking around 60psi at idle and once the car warmed up it settled in where you see it above, around 40psi. I have no idea how calibrated that gauge is, but I’m now comfortable saying that oil pressure is not the problem. And at the risk of jinxing something, we are now in the middle of the second round of high detergent Rotella T6 oil and it has been almost 4 weeks since the last check engine light. The ugly exhaust note above 4,000 RPM at heavy throttle is still there though, maybe it is totally unrelated to the VVT issue even though it seemed to go away when I had the oil control valve disconnected.