[Ironhead Dave]

Originally Posted by rt7085

I am ready about all these issues. It is not something silly like a missing ground braid, right? I believe there a ground connection on the (plastic) valve cover and one between the head and the chassis. Bad ground will do a lot of bad things at once. Just an idea.

I know the one from the head to the chassis is connected. I do not remember one on the valve cover. I wouldn’t think you would need one on a plastic part but if you can tell where it is supposed to be, I will definitely take a look

[nsjames]

the ones on the valve cover go through to the head on the VC studs, and are there mostly for the coils.

[Ironhead Dave]

Originally Posted by nsjames

the ones on the valve cover go through to the head on the VC studs, and are there mostly for the coils.

For some reason I was stuck on it being a strap and couldn’t figure out why there would need to be a strap to the cover. Yes. I do have those hooked up as well.

[fleet]

Originally Posted by Ironhead Dave

I have a N52. My plugs are brand new. I changed them thinking they might be part of the issue. Coils are unknown. The car ran perfectly but the VCG was leaking so I changed it and put it back together and here I am. It ran fine for a few miles and then started running rough. It got progressively worse untiil it eventually wouldn’t start anymore. I have got it to start but still runs rough and is not drivable.

Maybe I'm thinking of a different OP, but didn't you mention in your thread about spark-plug tubes that you found damage/cuts to at least one of your coil-pack wires and wrapped it in electrical tape? Are you still running those coil(s)?

[Ironhead Dave]

Originally Posted by fleet

Maybe I'm thinking of a different OP, but didn't you mention in your thread about spark-plug tubes that you found damage/cuts to at least one of your coil-pack wires and wrapped it in electrical tape? Are you still running those coil(s)?

That was me on a different thread. I had a specific question about the tubes in the holes for the coils. Yes I still have those coils in since I didn’t really feel like there was a definite answer as to whether they would still be ok. I ordered new coils and I am waiting for them. I did put in new plugs.

[mweisdorfer]

Originally Posted by Ironhead Dave

I have a N52. My plugs are brand new. I changed them thinking they might be part of the issue. Coils are unknown. The car ran perfectly but the VCG was leaking so I changed it and put it back together and here I am. It ran fine for a few miles and then started running rough. It got progressively worse untiil it eventually wouldn’t start anymore. I have got it to start but still runs rough and is not drivable.

Is the vacuum line plugged into the throttle body? If you are over 100,000 miles or even at 90k, change the coils. Use the Bosch coils for an N52. What brand of plug did you use ?

[Ironhead Dave]

Originally Posted by mweisdorfer

Is the vacuum line plugged into the throttle body? If you are over 100,000 miles or even at 90k, change the coils. Use the Bosch coils for an N52. What brand of plug did you use ?

NGK plugs. May I ask why the Bosch? My wife has a N51 and we went through two sets of Bosch in less than 50,000 miles. One set only went just over 10,000 and they were installed by the dealership. The last set are Delphi and have made it about 70,000. Is there something different about the N52?

I am pretty sure the trouble is in the Valvetrnoic system if I unplug the valvetronic motor and go into limp mode it smooths out considerably.

I will definitely check the vacuum line though. Whether it is part of this problem or not, it sounds like it could be in the future.

[juld0zer]

You seem to be able to watch the valvetronic eccentric shaft angle live so do this test:
- Connect a charger and turn it on
- Delete the faults
- Ignition on, monitor the eccentric shaft angle
- Disconnect the power to the valvetronic servomotor (unplug it)
- Use the allen key and rotate the motor and observe the values
- Report observations here

[mweisdorfer]

Originally Posted by Ironhead Dave

NGK plugs. May I ask why the Bosch? My wife has a N51 and we went through two sets of Bosch in less than 50,000 miles. One set only went just over 10,000 and they were installed by the dealership. The last set are Delphi and have made it about 70,000. Is there something different about the N52?

I am pretty sure the trouble is in the Valvetrnoic system if I unplug the valvetronic motor and go into limp mode it smooths out considerably.

I will definitely check the vacuum line though. Whether it is part of this problem or not, it sounds like it could be in the future.

Bosch is OEM. You haven't heard of people using NKG plugs on an N52. On N54's with a tune, yes. Also, Bosch coils are cheaper than the new updated ones and they work just fine. If you had a tuned n54, I could see one wanting the latest & greatest coils.

[Ironhead Dave]

Originally Posted by juld0zer

You seem to be able to watch the valvetronic eccentric shaft angle live so do this test:
- Connect a charger and turn it on
- Delete the faults
- Ignition on, monitor the eccentric shaft angle
- Disconnect the power to the valvetronic servomotor (unplug it)
- Use the allen key and rotate the motor and observe the values
- Report observations here

Here is what I got:
Ignition on and then back off- specified angle 66 actual 58

Ignition on after learning- specified 0 actual 58

Unplugged 1 full turn CCW- specified 0 actual 68

2 full turns CCW- specified 0 actual 78

2 full turns CW back to starting position- specified 0 actual 58

1 full turn CW- specified 0 actual 50

2 full turns CW- specified 0 actual 41

[juld0zer]

In Australia, genuine N52 plugs are now NGK. They were Bosch before. I'm not sure if BMW NA still specify the Bosch.

My apologies, can you also tell us what happens when you turn the motor shaft to one end stop (use just an allen key or socket by finger, no ratchet) and then to the other end stop? Do you also notice any stiffness?

Can you tell us more about your difficulty installing the ESS? Perhaps use a photo and add some notes to help us better understand it

[Ironhead Dave]

Originally Posted by juld0zer

In Australia, genuine N52 plugs are now NGK. They were Bosch before. I'm not sure if BMW NA still specify the Bosch.

My apologies, can you also tell us what happens when you turn the motor shaft to one end stop (use just an allen key or socket by finger, no ratchet) and then to the other end stop? Do you also notice any stiffness?

Can you tell us more about your difficulty installing the ESS? Perhaps use a photo and add some notes to help us better understand it

I will get to the stops tonight. I will say though that turning CCW I could feel tension. CW turned very free.

The ESS would not go in easily with the bolt holes lined up. By easily I mean just slide right in. I turned the sensor about 30 degrees CCW (toward the right side of the car) and it slid in easy and then I rotated it CW into position. I had no idea at the time what the mechanism looked like so I assumed that the shaft was keyed in some fashion and the sensor had to line up. Looking at pics online and my old sensor it appears that the sensor should use slide in and it is just a magnetic pick up.

[nsjames]

my junk has delphi coils and NGK plugs in it for the last 40K miles with no issue.
I pulled the plugs when I did the VCG and replaced them, because I was there, and they still looked fine with 38K miles on them.

I don't think they're nearly as sensitive to brand as people think. As long as you get them seated properly they work.

[fleet]

Originally Posted by nsjames

my junk has delphi coils and NGK plugs in it for the last 40K miles with no issue.
I pulled the plugs when I did the VCG and replaced them, because I was there, and they still looked fine with 38K miles on them.

I don't think they're nearly as sensitive to brand as people think. As long as you get them seated properly they work.

I agree. I can't help but think that the solution to OP's issues is going to end up being a simple one.

[Ironhead Dave]

Originally Posted by nsjames

my junk has delphi coils and NGK plugs in it for the last 40K miles with no issue.
I pulled the plugs when I did the VCG and replaced them, because I was there, and they still looked fine with 38K miles on them.

I don't think they're nearly as sensitive to brand as people think. As long as you get them seated properly they work.

I would tend to agree to a point. Like i said earlier, my wife’s car went through two sets of Bosch within 48,000 miles. We put Delphi in the last time and she just rolled 118,000 and they just went bad.

I think you hear good and bad about both. I looked up threads on here to see what everyone had to say and it was about a 50/50 split.

My car has 120,000. I bought it with 98,000. It has Bosch. I don’t know how long they have been in the car but until all of this came about, it ran great.

[nsjames]

have you smoke tested the ccv and intake manifold yet?

it's been like 3 pages, so I can't remember.

[juld0zer]

In one direction you will encounter spring resistance but it is geared as such that it should be rotatable by finger or a small 1/4 dr ratchet at the very most.

Was there any wear marks on the inside of the old ESS?

[Ironhead Dave]

Originally Posted by nsjames

have you smoke tested the ccv and intake manifold yet?

it's been like 3 pages, so I can't remember.

No I have not. I am not really sure how to. I have read some threads on it but i don’t have the equipment that i think i would need.

I didn’t get near the intake so I don’t think that is an issue. I only changed the VCG and it ran fine before that. I removed the insulation from the vent hose and inspected it and saw nothing obvious like a crack.

[Ironhead Dave]

Originally Posted by juld0zer

My apologies, can you also tell us what happens when you turn the motor shaft to one end stop (use just an allen key or socket by finger, no ratchet) and then to the other end stop? Do you also notice any stiffness?

Can you tell us more about your difficulty installing the ESS? Perhaps use a photo and add some notes to help us better understand it

So...i when you turn on the ignition, it always resets to 58 degrees. One complete revolution of the motor shaft is 9 degrees. CW rotation is very easy. It goes down by 9 degrees every revolution and stops at 0. CCW is fairly stiff. It climbs by 9 degrees every revolution and stops at 223.

I see no evidence of rubbing on the old ESS.

[Ironhead Dave]

Here are some pics. The first one is approximately how far from vertical I had to rotate it to have it seat easily. I wasn’t sure how much pressure was ok to use so I just pushed on it lightly and let it sway itself when it hit the right spot. At the time I thought that the center of the ESS seated in a keyed hole in the shaft and that is why it didn’t go right in.

The second pic is how far I turned from the first pic to get the bolt holes to line up.

The last three pics are self explanatory.

[nsjames]

Originally Posted by Ironhead Dave

No I have not. I am not really sure how to. I have read some threads on it but i don’t have the equipment that i think i would need.

I didn’t get near the intake so I don’t think that is an issue. I only changed the VCG and it ran fine before that. I removed the insulation from the vent hose and inspected it and saw nothing obvious like a crack.

the intake is connected to the valve cover through all of the CCV hoses.
smoke/pressurize the intake, you'll check everything.

https://www.garagejournal.com/forum/...d.php?t=299263

mine was far cruder. but a salvaged porpane regulator and about $20 of stuff and I had my own.

[juld0zer]

Is there any possibility the cam sensor plugs are swapped? I know the exhaust cam should throw a sync fault in some motors but intake is more important to starting the engine