[k04]

(Vehicle in question: 2006 BMW e90 N52 6 SPD)

I am typing this from my.phone, so please excuse the lack of specifics. Long story short, I just purchased an e90 N52 from a member here. The vehicle ran well, despite some common oil leaks on this platform. Specifically the OFHG, valve cover, and oil pan gasket. I figured I could take care of the three as I have most of the tools needed.

To get to the point, I did the OFHG without issue. It's a pretty simple job. I decided to knock out the Valve cover gasket last night, which seemed to be going well, but that wasn't the case once I started the car.

I'm getting violent shaking, very rough idle, basically a car I can't drive until fixed. I've read thread after thread. Obviously trying to diagnose over the internet is difficult. I've checked all the plugs, as originally I was getting CEL's for misfiring on basically every cylinder. I didn't change the spark plugs, so I went ahead and tried that. It still runs just as awful. The likely hood all of the coil packs went bad simultaneously seems rare. I also checked various plug connections, electrical connections, injector plug seating, pretty much everything besides removing the valve cover again.

I thought perhaps I had a vacuum leak from.the Valve cover itself, so I checked the Torque again. (Ended up snapping 1 bolt, so I have to deal with that now) I have to mention again, the vehicle ran perfectly fine, idle was smooth etc. I just wanted to take care of the leaks.

The only thing I can think of is, the valvetronic motor may be messed up, perhaps my own doing. The DIY I was following showed a screw from the center of the motor needing to be removed. I put the hex bit and rotated it a bit before realizing my motor does not have that same mounting screw. Maybe I messed something up doing so? It freely spun..

I'm stumped, and frustrated. Wrenching isn't always rewarding

Here's a video of my startup.

https://www.dropbox.com/s/g90ow4jt9n...85111.mp4?dl=0

Thank you for reading, and I'd greatly appreciate and help from someone more capable than myself.

[N52bigblock]

Do you have INPA or ISTA to check fault codes?

[juld0zer]

What car do you have? ie. Model and year, just so we know which N52 you have.

Tell us more about the valvetronic motor screw. There are 3 E8 bolts. You use a 4mm allen key or allen socket to wind the motor shaft to safely remove the motor.

You also need to initialise the valvetronic motor after the repair. I prefer to do this using via a scanner but there are some supposed shadetree tricks to do this without a scanner.

[W37V]

Double check everything and make sure you connected everything back as it should be.

You most likely have a vacuum leak somewhere. Did you check if there is any oil protruding from the valve cover. Check your oil cap (make sure it’s closed). Did you mess with MAF?

Are injectors seated properly?

[k04]

Originally Posted by neilj35

Do you have INPA or ISTA to check fault codes?

I so not, currently I just have an app I downloaded, paired with a Bluetooth OBDII.

[k04]

Originally Posted by juld0zer

What car do you have? ie. Model and year, just so we know which N52 you have.

Tell us more about the valvetronic motor screw. There are 3 E8 bolts. You use a 4mm allen key or allen socket to wind the motor shaft to safely remove the motor.

You also need to initialise the valvetronic motor after the repair. I prefer to do this using via a scanner but there are some supposed shadetree tricks to do this without a scanner.

2006 E90 6SPD (N52)

In that case I was unwinding the valvetronic, but the center bolt area just spun freely, there was not a bolt that came out like the DIY I followed. To remove the motor I had to unbolt 2 small etorx screws on each side. Also one underneath. Is there anyway to initialize via Bluetooth OBDII?

[k04]

Originally Posted by W37V

Double check everything and make sure you connected everything back as it should be.

You most likely have a vacuum leak somewhere. Did you check if there is any oil protruding from the valve cover. Check your oil cap (make sure it’s closed). Did you mess with MAF?

Are injectors seated properly?

I've triple checked everything, originally I thought I did not plug or misplugged one of the sensors. I've verified everything is correct. No oil leaking from the cover itself, so it appears the gasket is doing it's job and installed correctly. Oil cap is definitely closed. I did unplug the MAF which ran a bit better. It leads me to believe that it's vacuum related. Also, last night I tried taping the PCV hose that connects to the back of the valve cover, just to see if that was leaking. The car then would just start and immediately die.

[Biginboca]

Originally Posted by k04

I've triple checked everything, originally I thought I did not plug or misplugged one of the sensors. I've verified everything is correct. No oil leaking from the cover itself, so it appears the gasket is doing it's job and installed correctly. Oil cap is definitely closed. I did unplug the MAF which ran a bit better. It leads me to believe that it's vacuum related. Also, last night I tried taping the PCV hose that connects to the back of the valve cover, just to see if that was leaking. The car then would just start and immediately die.

My guess is also vacuum leak. You didn’t mess with any of the valvetronic rollers did you? After my MILV’s install I had my car running like that and it was a roller that was slightly knocked out of alignment. (This would only happen if you were playing with the rollers and valvetronic assemblies it wouldn’t be a product of just a valve cover change.)

Most likely since you have no leaks it’s that vacuum hose at the back of the valve cover is cracked somewhere, or the valvetronic motor/motor gasket isn’t seating right.

You can try to initialize the valvetronic before you take anything apart. It’s very simple the instructions are online it’s somehting like ignition on (not start) and let the car sit for 30 seconds. Then shut off for 2 mins and repeat. Then shut off and start the car.

[k04]

I appreciate the feedback, I'll try that once I get home today. As far as I can tell there are no other leaks. I've read a few instances that someone in a similar situation taped the hose and it corrected the leak. oddly enough when I attempted to do so it literally started and shut off.

[juld0zer]

06 would mean you have the metal valve cover, right? So if the rear crankcase vent line was broken (easy to do given the age of the plastic) then that would cause a vacuum leak/unmetered air. N52 with the metal valve cover also has an external PCV so if the vent line was handled incorrectly, any force may have damaged other components attached to it.

Did the valvetronic motor shoot out/fall at any point?

[PhaseP]

Originally Posted by juld0zer

06 would mean you have the metal valve cover, right? So if the rear crankcase vent line was broken (easy to do given the age of the plastic) then that would cause a vacuum leak/unmetered air. N52 with the metal valve cover also has an external PCV so if the vent line was handled incorrectly, any force may have damaged other components attached to it.

+1

OP try this, find the nipple on the crankcase ventilation valve (CCV) that is between fifth and sixth intake manifold runners (taking first runner as the one closest to bumper). Depending on your build date, you may already have a tiny hose attached to that nipple, or just a plastic dust cover thing piece. Pull out either from that nipple. If you had a hose attached block the hoses end so no air goes into it. Then find a similar size hose, rubber poly doesn't matter, that fits into that nipple and about 8-10 inches long and place it in there.

Before you turn on the car, gently blow into that new hose you attached to that nipple. You should be able to blow like one second and then not anymore. You should notice air flow that you caused by blow stops. If this is so, it is good, now you can go to second test. If you are able to blow into it for more than a short time, it means your crank case ventilation valve membrane is torn, and this may be additional issue to what you are having or it could be itself.

Assume the membrane was fine. Now the second test, start your engine, make sure if your car came with a hose that was on that nipple already that you had removed from the nipple is closed on its end. Then blow on the end of the new hose as you did before to keep the valve closed.
If the engine starts to run smooth when you close the valve like that by blowing into, and fluctuates rpms when you don't, it is indicating you have vacuum leak at either the valve cover to the CCV hose or connections, or at return hose from CCV to oil pan or its connections.

Because if you had intact not torn membrane inside your CCV (verified with first test), when you blow into it like that you push the membrane down which closes the valve. Valve closed, intake manifold side is blocked from valve cover and oil pan return hose sides; if there were leaks there they won't get into intake manifold that way.

When you manually close the valve, you may notice fumes coming out in that area of the engine, because if you close the valve like that, crank case blow-by gases will now completely escape out from the leak if there was one. If there was no leak, the pressure inside the crank case will start to increase, so don't hold the valve closed for long time. Only for a few seconds at a time. If you smell or see fumes coming out, you have leak.

(Valve cover enclosed air space is same as the crank case air space.)

[k04]

Originally Posted by juld0zer

06 would mean you have the metal valve cover, right? So if the rear crankcase vent line was broken (easy to do given the age of the plastic) then that would cause a vacuum leak/unmetered air. N52 with the metal valve cover also has an external PCV so if the vent line was handled incorrectly, any force may have damaged other components attached to it.

Did the valvetronic motor shoot out/fall at any point?

Correct, I have the metal valve cover. I did some digging last night and found the PCV crank hose cracked on the connection and had a hole in the hose area. I already ordered a replacement part. I am hoping it didn't damage the other PCV components, but just the CCase vent hose.

Valvetronic motor never fell out, and seems to be mounted securely.

[Ethan Skinner]

Just did this job as well on my 328i! A few culprits could be a cracked PCV hose I believe it's called on the backside of the valve cover. Also your ECS May have oil in the connector. My idle was so bad to the point where the engine would die in gear. Believe it or not if you took your intake off for the job some small leaks in the intake boot could be doing this. Unplug your MAF sensor and run the car to see how the idle changes. If it gets better then re assemble your air box and boots. I did not have access to a scan tool but if you do pull some codes and see what you got

Sorry just read the part of the thread where you said disconnecting MAF helped a little. In my case it only helped a little as well but when sealing the intake completely the problem was fixed. I'm on mobile sorry if it is poorly written

[k04]

Originally Posted by Ethan Skinner

Just did this job as well on my 328i! A few culprits could be a cracked PCV hose I believe it's called on the backside of the valve cover. Also your ECS May have oil in the connector. My idle was so bad to the point where the engine would die in gear. Believe it or not if you took your intake off for the job some small leaks in the intake boot could be doing this. Unplug your MAF sensor and run the car to see how the idle changes. If it gets better then re assemble your air box and boots. I did not have access to a scan tool but if you do pull some codes and see what you got

Sorry just read the part of the thread where you said disconnecting MAF helped a little. In my case it only helped a little as well but when sealing the intake completely the problem was fixed. I'm on mobile sorry if it is poorly written

Thanks for the info! I'll look over all of the intake etc. I just ordered a complete PCV system.

[k04]

Just installed the PCV kit. Everything went in properly and locked in well. After a little trial and error I reconnected all sensors and fired up the car. It starts a little rough and RPM fluctuates a bit. But once it drops to idle everything seems to be fine and it idles as it should.

I am still looking for the culprit. I have code P1415 now and in an attempt to see what the problem is I unplugged the MAF sensor. When I did this, the vehicle started without issue and idled perfect.

Could the MAF sensor be the issue?

[W37V]

Originally Posted by k04

Just installed the PCV kit. Everything went in properly and locked in well. After a little trial and error I reconnected all sensors and fired up the car. It starts a little rough and RPM fluctuates a bit. But once it drops to idle everything seems to be fine and it idles as it should.

I am still looking for the culprit. I have code P1415 now and in an attempt to see what the problem is I unplugged the MAF sensor. When I did this, the vehicle started without issue and idled perfect.

Could the MAF sensor be the issue?

It could. Clean it well including connectors.

BTW. If you still have slight hesitation / misfire.. try running some techron injector cleaner. It usually smooths things out.

[ramm_e90]

Any definite fix to this problem?

I have a similar situation to the OP. (2008 328i n52) Had VCG replaced by Indy shop, right after picking the car up I got SES and rough idle. Codes were Right/Left Bank too Rich and a MAF code about airflow. Car runs perfect while driving, but idled rough. It does not die though. Any time I start the car the RPM fluctuates for 5-6 seconds.

I cleaned the MAF, replaced the connector housing that plugs into MAF and cleaned the metal connectors that are inserted into the housing. I also used Techron fuel system cleaner twice.

Nothing has fixed it so far. Getting the OFHG replaced this week so I'll have them look at all the hoses.

[k04]

Originally Posted by ramm_e90

Any definite fix to this problem?

I have a similar situation to the OP. (2008 328i n52) Had VCG replaced by Indy shop, right after picking the car up I got SES and rough idle. Codes were Right/Left Bank too Rich and a MAF code about airflow. Car runs perfect while driving, but idled rough. It does not die though. Any time I start the car the RPM fluctuates for 5-6 seconds.

I cleaned the MAF, replaced the connector housing that plugs into MAF and cleaned the metal connectors that are inserted into the housing. I also used Techron fuel system cleaner twice.

Nothing has fixed it so far. Getting the OFHG replaced this week so I'll have them look at all the hoses.

I'm not sure what was the exact fix, I ended up doing a few things such as replacing the whole CCV system. If your issue was similar to mine, it's probably vacuum related and you have a leak somewhere. I definitely had a leak on my oil filler cap and CCV hose that connects to the valve cover.

[E90beamo]

Originally Posted by ramm_e90

Any definite fix to this problem?

I have a similar situation to the OP. (2008 328i n52) Had VCG replaced by Indy shop, right after picking the car up I got SES and rough idle. Codes were Right/Left Bank too Rich and a MAF code about airflow. Car runs perfect while driving, but idled rough. It does not die though. Any time I start the car the RPM fluctuates for 5-6 seconds.

I cleaned the MAF, replaced the connector housing that plugs into MAF and cleaned the metal connectors that are inserted into the housing. I also used Techron fuel system cleaner twice.

Nothing has fixed it so far. Getting the OFHG replaced this week so I'll have them look at all the hoses.

Did you ever figure your situation out? I’ve got the exact same issue after taking my car to an indy

[tom.gnade]

Originally Posted by Biginboca

My guess is also vacuum leak. You didn’t mess with any of the valvetronic rollers did you? After my MILV’s install I had my car running like that and it was a roller that was slightly knocked out of alignment. (This would only happen if you were playing with the rollers and valvetronic assemblies it wouldn’t be a product of just a valve cover change.)

Most likely since you have no leaks it’s that vacuum hose at the back of the valve cover is cracked somewhere, or the valvetronic motor/motor gasket isn’t seating right.

You can try to initialize the valvetronic before you take anything apart. It’s very simple the instructions are online it’s somehting like ignition on (not start) and let the car sit for 30 seconds. Then shut off for 2 mins and repeat. Then shut off and start the car.

Biginboca hey, I'm just about to install the MILVs sometime in the next few weeks - how do I avoid this issue you mentioned, misaligning the rollers?

[Biginboca]

Originally Posted by tom.gnade

Biginboca hey, I'm just about to install the MILVs sometime in the next few weeks - how do I avoid this issue you mentioned, misaligning the rollers?

Hey Tom,

The roller wasn’t sitting straight and centered under the MILV. So the best way to double check is just look the at the roller carefully after you do each MILV and make sure they are centered and square in their positions. Like look at the one next to the one you just did (that you haven’t touched yet) and make sure everything looks straight and centered just like it on the one you did. The rollers can shift side to side a bit and also twist a bit.

They will kind of snap into place after you insert the MILV but they don’t necessarily snap into the exact right place, which means centered and even. It’ll be pretty obvious if something isn’t aligned if you just look them over as you go.

Also I have done a few MILV’s installs now and just use the washers Marty includes and follow the directions carefully as far as the number of turns and the torque specs. Never once needed the special tools or whatever it’s a pretty straightforward job which you don’t need to sweat.