[NZE90]

Originally Posted by WheelNut2

I only checked the ESS for oil contamination. I haven't had a look at the cam position sensors at all.

Any suggestions for diagnosing ESS or CPS at all? Is there a specific parameter in ISTA I can use to investigate them? Should I get an oscilloscope, back pin them and check out the wave form? I really don't want to just fire the parts cannon at this problem.

ISTA can do that too.

[WheelNut2]

Update! Finally. This is fixed!

I installed new Vanos adjuster units (along with the updated vanos timing disks to suit the updated adjusters), new eccentric shaft sensor, new valvetronic motor seal, ESS seal, and a new valve cover gasket (wasnt leaking, but needs to be replacing as part of the service).

This thing runs super smooth now! Its noticeably smoother during low speed and low RPM driving.

Now, exactly which part solved the problem? I don't know for sure. I'd suspect it was the Vanos adjusters, but it could have been the ESS or valvetronic gasket. A buddy of mine who is a long time BMW tech had a quick look at the car in the drive way a few weeks ago and thought it sounded like a vacuum leak. There was a bit of oil around the valvetronic motor, so was it leaking vacuum? It didn't release any smoke when I tested it, so I kind of doubt it. The RPM of the car DOES change now when you open the oil filler cap, which didn't happen before. I couldn't see any damage or issues on the Vanos adjusters or ESS, but that doesn't mean that they weren't the issue.

[WheelNut2]

300km in. First code appears! Who would have guessed?

2A82 Inlet Vanos- "Control error position not reached" "error currently not present"

Why? I don't know. How? I don't know. The still runs well.
There is some kind of software that allows a person to log vanos input and outputs which I guess I'll probably have to get and see what is going on. Perhaps there is a certain temperature, rpm or condition that causes this vanos mismatch. I don't think INPA or ISTA can log data while driving, right? I'll try using Bimmerlink to log a drive to work and see if the actual and requested Vanos numbers match. Maybe I'll swap the vanos position senors and see the code moves from the intake to exhaust.

Oh, also the fuel consumption has increased by about 10% since I put the new vanos adjusters in. Curious. (edit: This is because BC switched to winter gas while I was doing the Vanos work. The fuel is less energy dense by about 10%. Coincidence)

Why is this car so good and also so shitty?! Hahah. Such a pain in the ass, but it doesn't drive like a Toyota so there is so much that can be forgiven.

[WheelNut2]

I’ve been doing some data logging with Bimmerlink. Seems like the Vanos set point and actual numbers are quite close. Idle speed is pretty even. Low rpm driving is still nice and even without lurching or hesitations like before.

The car now runs evenly, but it is coarse. The shifter vibrates at idle and the “smoothness” or “rough running” values seem pretty high. Its in all cylinders so I don't know what's going on just yet. Smoothness numbers bounce all over and are up 1100 positive or negative. Some cylinders are mostly negative numbers and some are mostly positive numbers.

Battery is starting to go now too. Starts are a bit slow. I can see the voltage dropping below 10V when the starter is running (not sure if that’s normal). Perhaps this is contributing to the coarse running. I was thinking to also buy one single coil pack and swap it in to see what happens. I'll update as I go.

CEL came back today (2024-11-01) 2A82 Intake vanos. Maybe the cam position sensor is going?

[WheelNut2]

I swapped the cam position sensors last week to see if the inlet vanos error code would follow the sensor or not. 2A82 code came back on inlet vanos, so the sensors seem to be working properly. Nest I will swap the Vanos solenoids to see if the code follows.

[WheelNut2]

Hey Guys,

2025 update here. Still no resolution to this, but plenty of 2A82 codes.

I swapped the cam position sensors- no change. I swapped the Vanos solenoids- no change.

I've had the CEL go on 4 or 5 times now. From my notes its gone off at:
195,151km
195,346km
195,556km
195,660km

Data logging on Bimmerlink was tough to decipher. There is a smidge of mis match between the Vanos set point and the Vanos actual for both intake and exhaust cams here and there, but its not much and the scale of graphs I'm getting is a bit of a mess. I'll try again I think, but there isn't some obvious huge mismatch where its off by a significant amount for more than a second. Also, that small discrepancy was there on intake and exhaust, but I'm only getting intake codes.

There is no degradation of driving function from this issue, but I HATE having a CEL on the dash. It just makes me nervous and this whole things makes me feel uneasy when I'm driving the car. Always thinking about "what was that noise?" " was that a rough idle?" etc.

[ptpending]

where did you bought vanos adjusters ? who is their manufacturer ? are they new ?
what oil are you using ?
was walnut blast was done when engine was disassembled ?
what kit you was using to fix the chain and rods during this operation ?

[WheelNut2]

Vanos adjusters are Febi Bilstein from FCP euro. Brand new.
Oil is Castrol synthetic 5-w40. LL01 approved spec. The inside of the engine is spotless. No sludge anywhere that I can see from having the valve cover off.
N52 is port injection. No walnut blasting needed.
I bought a timing kit on Amazon which seemed to work fine.

[RealJ22]

Originally Posted by WheelNut2

Vanos adjusters are Febi Bilstein from FCP euro. Brand new.
Oil is Castrol synthetic 5-w40. LL01 approved spec. The inside of the engine is spotless. No sludge anywhere that I can see from having the valve cover off.
N52 is port injection. No walnut blasting needed.
I bought a timing kit on Amazon which seemed to work fine.

Have you had the Vanos recall done?

[WheelNut2]

Originally Posted by RealJ22

Have you had the Vanos recall done?

You are referring to the recall for vanos bolts? There is no Vanos recall on the 2006 330i as the vanos adjusters used on the 2006 are different than later models that had the recall.

[VinnyK]

I wouldnt have installed those pos FEBI cam adjusters. Those are no different than the Chinese Ebay ones. I bought a set of OEM adjusters off a 2015 435i for $100 with 60k miles including the reluctor plate. Most likely there is left over material inside the adjuster causing it to jam or the check valve inside the adjuster is stuck or clogged. I plan on replacing those "recall" bolts, dissasemble each adjuster, thourogh cleaning, and installing these used updated cams whenever my valve cover gasket starts to leak. Also are your cam sensors OEM?

[WheelNut2]

Cam sensors have never been changed as far as I know.

Are the Febi adjusters junk? Maybe. The car does put the Vanos system into fail safe mode maybe once a week. I have my BimmerLink up on my phone most drives and I can see the cam angle set point vs actual, which has been pretty interesting as I've begun to learn what the normal values and fluctuations are. I really don't have time to replace these vanos units again, so I think these Febi adjusters will be in there for the foreseeable future. I ain't paying someone an exorbitant fee to replace them for me either.

My latest scheme is to try conventional oil to see if that helps in any way. I saw some video of a guy saying that conventional oil generally doesn't leak as much because the molecules are larger. This makes it flow better, but that means it can also flow out of tiny holes more easily. Not sure if that's really true or not, but if there is some leakage from the cam ledge seals then this oil might help. I filled 'er up with Castrol 10w-40 dino oil today. Will report back in the next few weeks.

[GloomyLizard]

Hmmmmm…… valve cover off. Turn engine over by hand and watch for oil leaking by the rectarings on the cexhahst/inlet camshafts. I believe early n52’s until 2009 had steel rings. Causing grooves to be worn into the exhaust cam ledge OR on the intake side, since the surface is actually in the head. It’ll need a head replacement.


Recently also just replaced cam adjuster units on a x5 that had a smoked exhaust camshaft and two failed lifters that smoked out two rocker arms to. Put used units in with new Valeo adjusters. Runs great but also has stumbling at start up. I’m assuming ESS on my end trying to find position on start up.

I’d like to believe your intake steel rings have worn grooves. Causing oil pressure loss @ adjusters bleeding by. The adjusters are purely mechanical I believe and only require oil to operate. Wether they are Chinese ones or not doesn’t matter. As long as they operate and function with correct oil pressure. The vanos solenoids allow that pressure to them.


You could take out your one way check valves again. Try blowing into them to see if oil is blowing by.


Timing chain tensioner is also hydraulically operated through oil. Although you may not be hearing the noise. On your old adjuster units did you notice @ the teeth were they worn at all like fresh metal like the chain catches on it? Usually a tensioner issue causing the chain to have slack blasting the gears on decel.


Anyways, you can easily check for MAF grams per second, should be near 3 g/s at idle.



Have you tried OBDII onboard testing for misfire data as well? What coil packs did you buy? Single LAM, 2 LAM or 3 LAM?

We will get through this together lmaoo… been driving n52 since 2015.

Your oil pump could be worn as well, but also, your pick up tube could be clogged. Wouldn’t hurt to check oil pressure on cold start vs warm start later in day and then compare to actual specs.

[WheelNut2]

The conventional oil definitely did not help matters. Not surprising really.

Nice tips Mr. GloomyLizard! I'll have a look at the MAF flow and look at those one way valves again. The old Vanos adjusters didn't have any abnormal looking wear. Everything under the valve cover was ultra clean. Its a shame and a surprise the engine doesn't have an oil pressure gauge from the factory. I have checked it, but not at hot and cold or while driving, so all I can say is that the engine when warm does have pressure while idling in my driveway.

Attached is a photo of the valvetrain before I removed the Vanos adjusters.

Annoyingly the N52 in the '06 has aluminum valve cover bolts, so to pop the valve cover off means I gotta buy a new bolt set, which is a frustrating expense.

I have not replaced the coil packs. The previous owner replaced them 75,000km (45,000mi) ago, so I figure they might be good still, but they are definitely suspect since the "rough running" values are quite high.

The real trouble for me at this point is that we just had a baby in the winter AND I bought an '06 Range Rover that has lots of issues and it is taking up what little free time I have available. The BMW has been left on the back burner. So, basically I have no money and no time haha. The car drives down the road just fine- the hiccups at idle are annoying, but I don't think its causing any trouble in accomplishing the goal of reaching my destination.

[WheelNut2]

Super rough idle on the way home from work today. Came off the highway and the idle was dipping and diving all over. It sounds like the engine skips a beat then the RPM drops, then pops back up slightly above idle. I logged some of this behaviour, so I'll chart it out tomorrow hopefully. The weird thing is that during these flucuations the intake vanos cam set point and actual measured angle were totally stable, but the exhaust vanos cam set point was jumping around and the actual angle wasn't able to keep up. I have the BimmerLink dash board up on my phone while I'm driving so I can watch the vanos angles in real time. The intake always tracks its set point more closely than the exhasut, BUT the vanos code I get is always for the intake vanos. Quite odd!
This behavious was significantly worse once the engine was hot (oil temp ~110C). Cold start was a bit jumpy too, but not nearly as bad. Today the worst idle the car has ever had by a huge margin.

[crashoverride]

The sensors can be swapped to see if the problem moves with the sensor indicating the bad sensor. Also just double check you have the proper amount of motor oil.

[WheelNut2]

I tried swapping the cam position sensors a fee months ago. Didn’t change anything. Oil level is okay according to the onboard computer.

Interesting thing watching Bimmerlink on the long traffic jam drive home today: The exhaust vanos solenoid PWM jumps around by 15-20% randomly while the intake pwm value moves but it moves in smaller steps AND when the exhaust pwm value jumps around so does the idle. Does anyone know what drives the vanos solenoid pulse width modulation value? What might cause it to jump around? Bad sensor data from elsewhere in the car? The vanos solenoids are genuine BMW that I installed less than 10,000mi ago.

[ptpending]

seem replaced vanos adjusters are not very good

[WheelNut2]

Curious thing that I just found after my last post: The idle gets much worse when the AC is switched on. Seems that the compressor can't decide if it should stay on or off and the engine is being loaded momentarily at random. The car is driveable and the idle is the same as it was after replacing the vanos adjusters with the AC off, which is to say there are some stumbles, but its not toooo bad. I will be taking the car in for an AC service in July.

One thing that I did notice a while ago was the the O2 sensors would read differently between bank 1 and bank 2 when the vanos goes into default mode. Maybe there is some issue with the injectors or coils after all. Anyway, I'll look into that in July.

[WheelNut2]

New coil packs have been installed and the car is running pretty smooth now. I had been hesitant to replace them as they had been replaced by the previous owner about 40,000km, which isn't a lot of mileage and the car wasn't throwing any misfire codes. None the less they were totally shot.
It still has a minor and constant vibration at idle. So, not sure what the issue is exactly. Maybe my cam timing is off by a smidge or maybe the Febi Bilstein Vanos adjusters don't quite cut it. There is a constant slight mismatch between the Vanos actual and Vanos set point angle for intake and exhaust. I'm not planning to tear the thing apart again to attempt to correct that, so I'll just live with the very slightly rough feeling engine. No codes yet in last 500km, but we'll see how it goes. I lent the car out to a friend for a day and he remarked on how smooth the powertrain was, so I guess I'm a bit more sensitive than the average person.