[Blackdog76]

Ive had a 2011 335d for around a year and have put about 3k miles on it. It has a reoccuring problem where it runs like crap at low rpm then the next day its back to a perfect idle and full power. Ive read all the posts about carbon buildup but that doesnt explain the back and forth differences in performance. if the intake is clogged, its clogged. most recently i got a code for the MAF 4c2d so i replaced it with a new oem unit.
I also got a 4674 code that some have said is related to the charge pipe. I noticed some oil on my pipe at the seal so i have a pipe from Forge motorsports on the way to rule out leaks.
My most reoccuring code is 4b06 which comes back no matter what.
The only mod i have is the JB4 tuner set to 60%

[335dlci]

So I assume you just threw the maf on without any calibration like a lot of n00bs do.

[Blackdog76]

The code went away, so I’m not worried about it. The codes that remain are the ones I’ve been getting for some time.

[alex sol]

if you have oil on your turbo to intercooler pipe (orange one) you could have failing turbo oil #3 (the one that's hard to reach and see) and if it fails, like mine did, you could really eff up your car like mine.

my kid kept driving with oil pouring out of the line and caused spun bearing (likely) and then catastrophic failure (rod through the side of the block)...

i have since replaced the engine and running again...

not sure that would cause your goofy idle / rough running issues... suggest to run car with diagnostics on all the time... at least you get volt meter, turbo boost and water temps, exhaust gas temps on the torque app

does this tie in with the dpf going or can you run get carly to run your dpf while going for highway drive... i think this is a must for cars without dpf deletes.. also carly tells you the soot level

[Blackdog76]

ill check the whole area when I install the new pipe but it doesn’t seem like a steady stream of oil. Just a Pinhole type leak with dirt stuck to the oily area.

[Blackdog76]

Quite a bit of oil while I was under there but I can’t tell where it was coming from other than the charge pipe. Cleaned it all with brake cleaner and left the cover panel off and will recheck for leaks. The car is boosting like it should again with the Forge pipe, back to pulling strong but idle still poor. No codes yet but something still needs attention. The 100k mile mark has been rough on my car.

[Blackdog76]

I’m on day three of a perfect idle, no codes and car is pulling really strong. Still trying to figure this out.

[Blackdog76]

Against the advice of the sticker on the fuel filler door I’ve been running some additives through the car. First I ran a Lucas top engine and injector cleaner and now running diesel kleen on every fill up. Car is running great and no codes have come back yet. Perfect idle, no stumbling.

[Blackdog76]

Back to idling like crap and throwing a bunch of codes. In order: 4679 3F40 3FF1 (new mass air flow sensor in Jan) 4B06 4674. Any thoughts based on these codes?

[Blackdog76]

A lot of what came up from searching was that the problem might be stemming from the JBD. Some have said if it gets wet it can malfunction and fry the fuel pressure sensor. I’m going to order one and remove/inspect the JBD.

[_N54]

Originally Posted by Blackdog76

A lot of what came up from searching was that the problem might be stemming from the JBD. Some have said if it gets wet it can malfunction and fry the fuel pressure sensor. I’m going to order one and remove/inspect the JBD.

If you need a new JBD from water damage i have one removed off my 335d.

[Blackdog76]

Thanks but if it’s truly the cause of all these problems I’m going a different route.

[Blackdog76]

Ok. So I replaced the fuel pressure sensor, removed the JBD. The JBD was filled with water...the case warped from the normal temp of the motor and let water in. Not to happy with Burger Motorsports at the moment.

[Blackdog76]

https://www.amazon.com/photos/shared...bD7admSwZial7G