P1415 and rough idle

**McDoubleMcTroub** · 10-25-2020, 05:34 PM

First off I have a 08 328I. I recently bought it and I hade some repairs to do. The Eccentric motor that sits on the valve cover (I didn't replace the motor) I had to replace the sensor that sits inside the valve cover and replace my thermostat. THe repairs went fine and dandy, reused the old valve cover, got a new valve cover seal, and changed the oil to Mobile 1 0w-40 European Mix, got the car to pass emissions and got it registered. After about 2 to 3 weeks of just normal driving, on my way to the store I smelled a burning sensation that came through my vents in the cabin. Some white smoke came through and I immediately pulled over to investigate. Knew I had a problem, but didn't know where. 5 to 10 min later, I dropped the problem and just went home and parked the car. I use the car for work only really. To and from work is the only time the car gets driven besides out of the occasional run to the store. 10 to 15 min drive one way. Anyways, I discovered the problem. A leaking valve cover where the oil is getting burned on the exhaust, its the middle 3 bolts on the passenger side part of the valve cover but mainly its coming from 1 single bolt. Not a single drop on the ground. I haven't had the time to fix the problem, but I have been keeping a close eye on my oil level and really have been babying the car whenever Im driving. On my way home from work, and after I parked the car, I popped the hood to see how much smoke is coming from the problem area, but just before I stepped out of the car my SNS light came on. Curious, I grabbed my scan tool and the code P1415 (Mass or Volume Air Flow Too Low). I've been looking around for some problems that match mine, but to no avail. The car has always run rough since I got it. My father and I have come to the conclusion that the VANOS sensors need to be replaced, but other than that no other issues on the car. I got the P1415 code cleared and just started the car and left it on idle. Gave some gas every now and again, and got the code to pop again. Once it popped the RPM dropped to 500 and the car started shaking. I immediately stopped the car just in case of something major breaking. As of now, Im at a loss. I don't know where to start (besides vacuum lines) and or what to look for, And and all help will be greatly appreciated.

I'm trying to add as much detail so its easier to formulate whats wrong.

Update:
After replacing the Valve cover, It was leaking from the Valve Tronic Motor seal itself and leaking and burning off.

**White94RX** · 10-26-2020, 07:57 AM

Sounds like you've got a vacuum leak. It's possible the valve cover gasket came out of the slot when you put the cover on and is why it is leaking oil. I'd start there. Or the diaphragm in the valve cover itself could also be bad. We replace the covers at a certain mileage once they start leaking.

**McDoubleMcTroub** · 10-26-2020, 04:14 PM

Originally Posted by White94RX

It's possible the valve cover gasket came out of the slot when you put the cover on and is why it is leaking oil.

Idk, I really don't think the seal came out of its spot. The car didn't leak oil for 2 to 3 weeks after I put in the new seal. Every bolt got tightened down to 89 inch pounds, and I do only thing its leaking around 1 bolt. Maybe that bolt wasn't tight enough. Prob going to get the torque wrench out again and check all of the bolts again to be safe. But I am planning on just replacing the whole Valve cover and getting a new gasket for it aswell.

I also don't think its a vacuum leak either. Ill inspect all vacuum lines, but if I had a vacuum leak, I feel like I would be getting more codes that just P1415. Like Air to Fuel ratio too lean or other codes that affects performance. I am not the smartest when it comes to cars, but like I said I will check vacuum lines.

**White94RX** · 10-26-2020, 06:35 PM

Your fault code indicates a lean code, correct? I’m not familiar with generic OBD codes because they are barely more than worthless. It may just be time for a new valve cover.

And on an N52, how many vacuum lines are there? None? There’s a vent hose that connects to the back of the valve cover, maybe it’s broken.

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**McDoubleMcTroub** · 10-26-2020, 07:11 PM

No, but it was a code for my MAF. P1415 (Mass or Volume Air Flow Too Low). I ran a test. I unplugged my MAF and started the car, she ran like new... no stumbles and nothing wrong with idle. Plugged MAF back in, stumbles and idle surges +-100 rpm. I cleaned my MAF and sprayed out my air filter and the box. The Filter seems pretty new and in good shape. Fixed the problem. The hose on the back of the valve cover is good. I just need a new valve cover then. Why did they have to make it out of plastic... sigh.