PCV valve goosed?

[MarkG - E85]

Hi all....again

I've been having a few problems with the check engine light being on. It comes up as the camshaft sensor position B, so I changed that but to no avail. An auto-elec company said they wouldn't touch it as it was probably the VANOS system. I removed the solenoids and cleaned them, still hasn't worked. Changed the oil over the weekend....twice! Drained the old oil, filled it with cheap oil and some engine flush, ran it for 20 minutes, drained it and filled it with good oil in the hope the flush would clear any gunk, still hasn't worked.

When I was replacing the plastic lid on the rocker covers, I had the engine running but couldn't replace the cover with the oil filler cap on, so rather than stop and restart the engine, i just took the cap off in order to slip the plastic cover on and refit the cap. When I took the cap off there was a fair amount of gas pressure coming out of the opening, so much so that it was spitting oil out at me.

After I go everything back together i started doing some research and I got to thinking it could be a blocked PCV valve casuing the engine light to be on, would this cause the B sensor to show up as a fault?

Also, it looked as though the PCV is below the intake manifold which is a time consuming job especially in this cold weather. But then I came across a post that said on my particular engine, the PCV is built into the rocker cover itself so it would simply be a case of taking the cover off and cleaning the valve. Does that sound about right? My engine is an N46 on a 2.0lt 4 pot on a 55 plate.

It's booked into a BMW specialist tonight!! If tehy have to carry out the repair, any idea how much it will cost as a rough estimate??

[enuff_zed]

So did you get anywhere checking the eccentric shaft sensor, making sure it was signalling the servo motor and that the motor was operating?

[MarkG - E85]

I didn't get that far Zed, I checked the sensor for oil/water etc and it was all good. I was up against the clock as it was getting dark.

[enuff_zed]

Screenshot 2023-12-04 111251.png (89.16 KiB) Viewed 308 times

[enuff_zed]

I didn't get that far Zed, I checked the sensor for oil/water etc and it was all good. I was up against the clock as it was getting dark.

So there could still be a problem with that.
A good code reader will a show you live data so you can see if the cam positions are moving.

[MarkG - E85]

Yeah, this is one of the pics I found but is the valve in the separator or is it in the connection on top of the rocker cover? If it's in the cover I may put a half-day holiday in for this afternoon and have a quick look at it.

[enuff_zed]

Yeah, this is one of the pics I found but is the valve in the separator or is it in the connection on top of the rocker cover? If it's in the cover I may put a half-day holiday in for this afternoon and have a quick look at it.

If you found this ok on Realoem then you should also be able to view the image of the cover. Nothing like a valve shown anywhere on that.

[MarkG - E85]

Yeah, that's what I was thinking, it looks like it is buried under the intake manifold. going to be a big job labour wise if it is the PCV.

[enuff_zed]

Yeah, that's what I was thinking, it looks like it is buried under the intake manifold. going to be a big job labour wise if it is the PCV.

Relatively straightforward in fact as far as I can tell.
Simple nuts and bolts job, with new manifold seals needed.

Caveat: never done one but wouldn't shy away from it.

[MarkG - E85]

I agree, I'd just need a day off work.......and somewhere under shelter to do it. It's booked in for tomorrow so I'll get an assessment and see what they say, if it's a reasonable quote I'll probably just let them do it but if it's going to be through the roof, I'll do it myself. MOT runs out on 15th so I've got till then to do it.

[MarkG - E85]

UPDATE: The BMW specialist has had a look (at a cost of £48) and apparently the B sensor isn't getting a signal from the ECU so it's either the wiring or the ECU itself. They want me to book it in for another 2 hours so they can look a bit deeper to pinpoint the exact fault. If I can find out which block the B sensor is connected to in the ECU, I can test it myself. Does anyone have a wiring diagram of the ECU so I can locate the correct terminals?

Cheers

[Zedebee]

Does anyone have a wiring diagram of the ECU so I can locate the correct terminals?

Is this helpful?
X60007 is the natural (i.e. not black or grey) 26-pin connector
Looks like pin 12 and 25 are the terminals, assuming the B sensor is Camshaft sensor II.

IMG_0028.png (209.35 KiB) Viewed 203 times

[MarkG - E85]

Hi Zed,

This is hopefully helpful (I'm stuck at my desk at work so can't go for a look) but there are three wires in the cable, I'm assuming these two are the permanent live and the switched (signal) live.
Hopefully the connectors are labelled in the ECU.

[MarkG - E85]

I've just spotted that terminal 25 is the ground so I'm guessing the permanent live doesn't go through the ECU

[MarkG - E85]

And then again I've just noticed that the eccentric sensor has a supply (permanent live) as well as a signal (switched live) as well as a ground. Wonder why the camshaft sensors l and ll don't have all three going through the ECU?