3.0si N52 problem with initial starup

[belcom]

Before I started doing maintenance on the car it started fine but did have some initial hesitation, after maybe 5-15sec of rough idle it goes to normal and there is no idle problem when driving.

I did the following work on it:
1. Pulled the whole intake manifold and replaced CCV with brand new genuine BMW part, I took the hoses off very carefully and they're all fine. Did not break. Intake manifold did not have any excessive amount of oil inside, just a bit but my understanding its normal.

Note: Observation of the CCV operation before and after: when engine on, I opened oil cap and heard/felt some suction, but the engine didn't really do anything, just kept running the same. With new CCV installed, when I open the oil cap now there's almost no suction but as soon as its opened I can hear the engine idle changes a bit, I hear a kind of like suction noise around CCV area and its running a bit rough with cap open. When oil cap is closed it goes back to normal. I believe that is normal and how it should be. Correct me if I am wrong.

2. Cleaned out non-return valves (these were fairly clean to begin with, no sludge whatsoever)
3. Took out and disassembled VANOS solenoids, cleaned them out completely and put back together. No sludge. But when shaken, the movement is questionable.
4. New belt and belt tensioner (INA tensioner, same as genuine part)
5. New genuine air filter
6. Oil filter housing and oil cooler gaskets (elring)
7. Took out DISAs and checked with INPA. flaps were solid. Movement perfect. Then took them apart and replaced the flap, spindle, gear with metal parts by I6 Automotive, replaced the seal. When I opened these, there were no oil or sludge inside. all clean. I put them back together and tested with INPA again. They close and open same as before after rebuild.
8. Replaced spark plugs with NGK platinum specific model for N52 so I believe these were pre-gapped already. At the moment I put the old spark plugs back in for now but problem is the same so spark plugs don't cause the issue.
9. When taking things apart I also cleaned throttle body. It was pretty clean though, I did move the flap by hand for cleaning.
10. Intake manifold gaskets were also replaced

After first start up when everything was put back together I got a bunch of codes but then cleared them, it was quite rough in the beginning but then smoothed out.

Problem: Every time I start the car now cold or warm, I get really rough idle in the very beginning and most of the time if I don't give it a bit of throttle it just dies (like the original problem I had but amplified quite a bit).

And then I get VANOS inlet valve jammed code. So obviously I mucked something up when taking them apart. Then I ordered new VANOS solenoids, aftermarket by Standard Auto (made in Poland, originating from Germany) and put them in yesterday but the problem has not changed a bit. Still almost dies on start up but then runs perfectly while driving.

Help?

[drocket77]

Depending on scanner used, can you do a relearning? I think there may be a way to do it without a bi-directional scanner. Or if you have INPA you can reset adaptations.


1. Please make sure the ignition is Turned Off

2. Press the Gas Pedal to Full Throttle (while ignition is off).

3. Turn on the Ignition to the 3rd position for 30 seconds (Do Not Crank the Vehicle) (Do Not let go of the Throttle)

4. After 30 seconds are over, Turn Ignition Off and Remove Key (Do Not let go of the Throttle).

5. After Key is Removed, let go of the Throttle and wait 30 seconds.

6. After 30 Seconds, the Car can now be Started normally.


As far as VANOS is concerned, it could be something else in that line causing it to throw that code. I am on my 5th different MAF sensor, and it is still throwing a code for it. When it comes to mechanical issues, I have no problem at all, but electrical issues are another beast.

[belcom]

Thanks for the suggestions. I did reset Throttle valve, VVT and VANOS adaptations with INPA but to no avail. Still happening. Although I had noticed specifically when I reset VVT it started fine twice right after that but then back to same problem.

I also tried disconnecting the MAF and it kind of changed the behavior. Instead of dying right away it sort of hunts (RPMs go up and down) and then stabilizes later. I cleaned the MAF with CRC MAF cleaner but same thing. Don't think that's it.

I need to check the fuel trims I was told. I don't think there's fuel supply issues. It starts right away, no long cranks.

Battery was fully charged last week too in case there were voltage supply issues.

I also came across an interesting video by BMW doctor (Dean) about updating modules to latest but not sure if this is plausible scenario as of yet.

RESOLVED: vanos solenoid connectors were swapped not sure how I missed it but that's what happened.