[faviles]

Hi everyone!

I just picked up a used 2007 328xi with 155k on the dash for 2800.

Prior to buying I already knew the CEL was on and it needed a window regulator.

On cold starts, the rpms would go up and down rapidly with your foot on the brake, take your foot off and the rpms dropped and the car felt fine. If you push the brake again it will either shoot up the rpms or fluctuate again. After a few minutes or second with the car on those symptoms go away.

First code that popped up before driving it home was a P116E, which pertains to the MAF sensor.
When I got home and rechecked the codes I got another one: P0135, O2 Sensor heater malfunction bank 1 sensor 1.

So I chose the cheapest option first and cleaned it off with some AutoZone cleaner when I brought it home. I cleared the code and reinstalled it, started the car and the same symptoms were there.
I then shut it off and then restarted again, and the CEL came right back on only showing the original P116E code.

Should I just bite the bullet and assume the MAF sensor is bad? I checked for vacuum leaks and didn't seem to find any.

Thanks in advance for any input!

[faviles]

Just an update for anyone interested:

Replaced the MAF sensor with a brand new BMW one and reset the ecu with my ELM327. When I start the car with my foot on the brake, the rpms no longer jump up and down.

After a while I noticed that in park idling it still had a slight rough idle. I shut it off and turned it back on and the SES light came back on. Now I have a P00BC code, MAF air flow too low.

At this point I have no idea what it can be as the cables to the MAF are fine and the part is new. The car drives normally, but at times before coming to a stop it'll jerk like there's a misfire. If I find something else I will update again for those interested.

[crashoverride]

I think when you replace the MAF it gets weird having gotten used to old sensor

[faviles]

Originally Posted by crashoverride

I think when you replace the MAF it gets weird having gotten used to old sensor

What exactly do you mean by this?

Just another update: I put in a new air filter as the old one was pretty dirty, I also attempted a vacuum leak test with my fog machine on the intake boot but didn't notice any leaks. What I did notice was that the fog that came out of my oil cap when opening it was little to none. Could something be clogged and restricting the vacuum system?

With the new air filter installed the code went off, but the rough idle is still there and now the car stalls and shuts off at random times.
I now have pending codes p0174 and p0171. I have read that a lot of people with these codes set on either replace the valve cover or spark plugs and coils.
I will be doing the valve cover, gasket, and spark plugs this weekend. Hopefully this helps.

[faviles]

Another update, I changed the VCG and and actual valve cover as well.

Started up the car and p0174 and p0171 are gone. Now I am getting the P00BC with P1017 and P1006 which leads me to believe that the eccentric valve sensor is now bad as well. I checked for any oil prior to doing the job and saw nothing, which is why I left it alone.

Should I jump the bullet and just install a new sensor or are there other ways of testing it fully? Would this also trip the P00BC code?

[odin0941]

Originally Posted by faviles

the rpms would go up and down rapidly with your foot on the brake, take your foot off and the rpms dropped and the car felt fine. If you push the brake again it will either shoot up the rpms or fluctuate again.

This happened to me when I was checking my MAF sensor when I unplugged it and tried to test the car without it, putting it back on returned everything to normal, just wanted to share my experience with this, it also seemed to make the car more stable and quieter so probably needs cleaning but I did read somewhere that replacing it you will need to reset something on the ECU which I assume you did? Maybe not jump the bullet and try to think about how much you're spending, I saw the rest of your post and it feels like there's something hidden that you might've gotten to or it's not at all what you're fixing

[faviles]

Changed out the eccentric shaft sensor, upon further inspection, the old one did have oil on it.

Replaced the valve cover, and actual gasket as well.

Car still idles funny, now have P00BC with P0174 and P0171 pending again. I'm going to post some fuel trim data. Hopefully someone can help out.

Thanks!

[faviles]

These are the fuel trims for the P00BC code.

[faviles]

Another update for the ghosts of this thread.

I might have found the problem. So all along I would hear a tapping or clicking sound near the intake. I originally thought this was the throttle body opening and closing due to a vacuum leak however upon closer inspection the tapping noise as idle is coming from the DISA valve.

It almost sounds as if the motor is actuating but not staying closed or open and keeps attempting to fix itself randomly at idle. I have read that lean codes are often associated with the DISA going bad. I will be taking a look at it today.

P.S. already had the car smoke tested with no vacuum leaks.

[CoffeeJDM]

Originally Posted by faviles

Another update for the ghosts of this thread.

I might have found the problem. So all along I would hear a tapping or clicking sound near the intake. I originally thought this was the throttle body opening and closing due to a vacuum leak however upon closer inspection the tapping noise as idle is coming from the DISA valve.

It almost sounds as if the motor is actuating but not staying closed or open and keeps attempting to fix itself randomly at idle. I have read that lean codes are often associated with the DISA going bad. I will be taking a look at it today.

P.S. already had the car smoke tested with no vacuum leaks.

Basically almost never fails MAF sensor. You should check for intake leaks, check valvetronic gasket, camshaft cover gasket or maybe damaged vacuum valve which is integrated in camshaft cover (but it's still possible to change it without changing entire camshaft cover) but i see u already did it. So check MAF to ECU wiring, fuse. If need more info, i can post wiring diagram.

[faviles]

Originally Posted by CoffeeJDM

Basically almost never fails MAF sensor. You should check for intake leaks, check valvetronic gasket, camshaft cover gasket or maybe damaged vacuum valve which is integrated in camshaft cover (but it's still possible to change it without changing entire camshaft cover) but i see u already did it. So check MAF to ECU wiring, fuse. If need more info, i can post wiring diagram.

Hey Coffee,
I'd appreciate it if you could share the diagram as I plan on relooking over everything this weekend. Thanks a lot!

[CoffeeJDM]

Originally Posted by faviles

Hey Coffee,
I'd appreciate it if you could share the diagram as I plan on relooking over everything this weekend. Thanks a lot!

Do you know how to check wires? if not i can help u too
ECU is in passenger side, u need to remove upper panel under the hood, and remove white plastic cover.

[faviles]

Thanks a lot for your help man. That's awesome.
I do know how to check the wires and what not with a voltmeter. But I do not know what the standard for each wire should be in terms of readouts.

I can also see that the MAF is inline with the DISAs, which like I said, one has been making a loud clicking noise at random times.

[CoffeeJDM]

1 wire ground, 1 wire 12v, others should be around 5v

[faviles]

This is the noise I'm hearing from the DISA valve. I'll be checking it out this weekend. If anyone suspects anything let me know

Thanks

[CoffeeJDM]

Originally Posted by faviles

This is the noise I'm hearing from the DISA valve. I'll be checking it out this weekend. If anyone suspects anything let me know

Thanks

It's not ok, both valves should be closed while car is idling, only from higher RPM they should open So I guess, something wrong with ur wiring. Every time, when you get some electrical error, you should start from checking wires

[faviles]

Originally Posted by CoffeeJDM

It's not ok, both valves should be closed while car is idling, only from higher RPM they should open So I guess, something wrong with ur wiring. Every time, when you get some electrical error, you should start from checking wires

Thanks Coffee, any idea what the normal numbers should be for the plug on the DISA valves? I'm going to check what they put out through the connectors at idle.

[CoffeeJDM]

Originally Posted by faviles

Thanks Coffee, any idea what the normal numbers should be for the plug on the DISA valves? I'm going to check what they put out through the connectors at idle.

Turn ignition on, 1 pin - 5v, 2 pin - ground, 3 pin - 12v

[faviles]

Another update:

Upper DISA was pretty much non existent. Found the flapper inside the intake as well as the metal pin that holds it in. The lower one looks fine and has no play, but it was the one making the strange clicking sound so I will be replacing it as well.

Hopefully this is it! I will update once again after putting it all back together.

[IanM19]

Hmm, you may have just given me an area to look. I have the same year same car. With what I can only describe as "ghost misfires". Misfire codes that I don't physically feel, and that only seem to come on cold start or sometimes restart. Been through the ringer with this one...

[faviles]

Just took her to an indy shop y'all, they hooked her up to a smoke tester and smoke was pouring out from the crankshaft seal. Going to get that replaced and we'll see what happens next 🙄

[faviles]

SOLVED: it was in fact the crankshaft seal. no more engine lights (put around 50 miles on it), no more rough idle, my advice, if you get these codes, don't waste time and get a professional smoke test asap.

Hope this helps someone.