[sa1lor]

Due to all of the great information and help with my E36, E46, and E90 that I have received from this forum and others over the years, I felt compelled to share my recent experience with the PCV valve and Eccentric Shaft Sensor going out on my 328i with 128,000 miles.

After my car spent the night parked downtown on an approximate 10 degree right to left incline, I had an extremely rough start and idle followed by an ungodly high pitched scream coming from the engine. I revved it a little and the whine went away briefly before I set off for home. The car felt fine between 2.5k and 3k rpm on the interstate but felt like it was going to kill at idle. An extremely uncomfortable feeling, not to mention all of the glaring eyes I received due to the insanely high pitched scream coming from under my hood. Long story short, the engine quit on me as I pulled onto my street, I parked it and hit the forums. After discovering that it could be a torn PCV valve, and learning I was now in the market for an entire new valve cover since the valve is integral to it, I stumbled upon a video of someone on an E39 removing the oil filler cap while the engine was running. The leaking valve was evident due to the cap being sucked onto the valve cover. Oddly enough the screaming noise went away for an entire day after I removed the oil cap...

After deciding that the valve cover DIY was a little more involved that I cared to perform, due to time constraints, and lack of tools, I dropped the car off at
a BMW indy the next morning, the valve cover was replaced ($900 after tax) and I was back on the road the next day.

Fast forward 2 weeks, I hopped in my car to head to work and...crank but no start. After several cranks and a stomp on the floor, she started but once again extremely rough idle. Once again I hit the forums and found that I could have clogged/dirty VANOS solenoids. So I pulled them and cleaned them up, reinstalled, and the car was running completely normal. Went to bed feeling like champ... until the next morning...crank, no start, and EVERY light on the dash went on (ABS, DSC, CEL, etc...). Finally got it to start and ran the codes... P103A (VVT Sensor Temp Too High), P1017 (VVT Guiding Sensor Plausibility), P1056 (VVT Control Circuit High), then drove it straight back to the indy who determined it was the Eccentric Shaft Sensor which we just had access to with the valve cover off....

Tack on another $900...back on the road and everything seems A-OK.

Happy driving everyone.

[bluewater328]

Damn that sucks. Please post this in the N52 valve cover DIY thread so people understand why (on high milage cars) it might be best to spend the $200 up front, regardless of the current state.

[hassmaschine]

IMO it was likely damaged during the R&R of the valvecover. There are numerous N52s with far higher mileage on the original sensor, so I don't think they fail generally because of age. Either that or perhaps the more leak prone plastic cover leads to the sensor failing sooner than it otherwise wood.

[bluewater328]

Originally Posted by hassmaschine

IMO it was likely damaged during the R&R of the valvecover. There are numerous N52s with far higher mileage on the original sensor, so I don't think they fail generally because of age. Either that or perhaps the more leak prone plastic cover leads to the sensor failing sooner than it otherwise wood.

All possibilities, but the ESS sits on the front side of the cover where it seems highly unlikely to receive an impact (not sure it would do much anyway). Gasket could soften the blow if the cover was somehow slightly misaligned — though I have seen people say they put the gasket in after they dropped the cover. But only thing you could really do there is clip one of the connection tabs. Functional parts are below and the contact points are recessed.

Only thing I could see is if oil somehow dripped into the exposed sensor connection when removing the VC - which a different way to get the same common failure. Which would suck if you didn't notice when it happened.

Anyway, thanks again for sharing.

[matteblue3er]

Did the indy relearn the end stops after replacing the VVT motor?

If the end stop positions are out of sync, you will have rough idle and stalling conditions. ESS faults are common.

I hope you're indy didn't just slap a $900 part into your motor because his computer said so

[sa1lor]

Originally Posted by matteblue3er

Did the indy relearn the end stops after replacing the VVT motor?

If the end stop positions are out of sync, you will have rough idle and stalling conditions. ESS faults are common.

I hope you're indy didn't just slap a $900 part into your motor because his computer said so

I honestly do not know. But he did not replace the VVT motor, it's still the original one. But he obviously did have to remove it when he replaced the valve cover. Do you still have to have to relearn the end stops if you don't replace the motor with a new one? Also, what does "relearning the end stops" actually mean?

[hassmaschine]

you don't need to make it relearn the stops after removing and reinstalling the motor. It does that on its own.

[El Cheapo Loco]

Not replacing the ESS while replacing the VCG is like gambling. It's a bet that pays $300 but you may lose $900. Makes no sense to me.

[matteblue3er]

Originally Posted by sa1lor

I honestly do not know. But he did not replace the VVT motor, it's still the original one. But he obviously did have to remove it when he replaced the valve cover. Do you still have to have to relearn the end stops if you don't replace the motor with a new one? Also, what does "relearning the end stops" actually mean?

You should relearn end stops anytime the VVT motor is removed. If it's replaced EXACTLY how it came out, you can sometimes get away with not relearning the stops. But if you have the tool, the procedure takes minutes and is a no brainer to do to have peace of mind.

The ESS sensors do not know what the start and stop position is. The calibration procedure lets the sensor (or rather DME) know the absolutely min and max shaft positions.

The procedure at ignition switch is a self-test procedure that verifies shaft position and that there is no obstruction in the system. It makes sure it can fully actuate the eccentric shaft from min to max. (This is cycling sound you hear) This does NOT relearn end stops.

If you don't relearn end stops and the shaft is out of sync, the sensor will read that the shaft has exceeded the min or max positions and throw faults.

[frisbeeguy]

Your Indy made a lot of nice BANK

[rjahl]

Originally Posted by matteblue3er

You should relearn end stops anytime the VVT motor is removed. If it's replaced EXACTLY how it came out, you can sometimes get away with not relearning the stops. But if you have the tool, the procedure takes minutes and is a no brainer to do to have peace of mind.

The ESS sensors do not know what the start and stop position is. The calibration procedure lets the sensor (or rather DME) know the absolutely min and max shaft positions.

The procedure at ignition switch is a self-test procedure that verifies shaft position and that there is no obstruction in the system. It makes sure it can fully actuate the eccentric shaft from min to max. (This is cycling sound you hear) This does NOT relearn end stops.

If you don't relearn end stops and the shaft is out of sync, the sensor will read that the shaft has exceeded the min or max positions and throw faults.

As far as I know, you only need to turn the ignition on and wait a few seconds before starting the engine. This gives the DME time run the Eccentric cam to the stops.

Yes it will store a fault but if given time to relearn it will run fine.

The DME initiates the relearn anytime it measures a movement in the eccentric cam when powered up.

If it's not given time to relearn and you start the engine, you will get the error plus Emergency mode.

At least this is how my E85 worked.

Not much difference to me anyways, I used INPA so much for checking and clearing, I can't imagine working on a BMW without it.

[hassmaschine]

Agreed.

You dont need to do anything. The DME will run the proceedure on its own. Just turn on the ignition and let it sit for a minute.

[desertman123]

When you put the key in you can hear the valvetronic motor doing its thang