[335NJ]

This has become more and more frequent, and I have no codes stored when it happens. The only thing I need to fix that I'm aware of is the battery because it's shot, but that doesn't have much correlation with this problem I don't think. The dip in idle happens 2-3 times, and its always after a minute or so of idling from a cold start. Fuel is 93 from Costco FWIW.

Plugs are fairly new (6-8k on OEM), not sure on how old the coils are, and injectors are originaI I believe. No issues at WOT, or after the engine is warm and is started. Sounds like a leaky injector which is typical, but I would expect a misfire code on startup or at some point during the cold start idle.

I'm re-inspecting and testing all vacuum lines this weekend, but they all were good during a pressure test about 2 months ago.

Any ideas!? I'll try and capture this in a log as well, that will give good insight.

[335NJ]

Got some codes I found stored but no CEL ever came up, and auto clear is disabled. Also the dip in idle happened again after having the car off for about 30 minutes from a full op. temp drive to/from the gas station.

2FBE - Fuel Pressure after motor stop (I'm leaning towards fuel pump issue now)

2DC3- Control clamp 15 (???)

2A17- DMTL Diagnosis module tank leakage (saw this once before)

2E8D- IBS signal transmission (I'm assuming that's because the battery is toast)

Time for some googling while I wait to see what you guys have to think.


Here's a log at idle, not duplicating the issue in this log, but it's worth having. Any thoughts on the AFR & AFR2 varying like they are? I'm wondering if a bank of injectors are to blame here.

http://datazap.me/u/shafer/idle-71-d...25-26-27-28-29

[335NJ]

UPDATE: I have a friend with an 08' 335 6MT as well, and since the last BEF update, his car does the exact same thing. Strange.

Most recent PUMP flash, mine is I8A0S, his is IJE0S

[Jeff@TopGearSolutions]

Do you have a Cable and INPA?

I'd look at the rough idling section and look at the injectors.

Original injectors on an 08 is scary. You should replace all 6 just for peace of mind.

[335NJ]

Originally Posted by Jeff@TopGearSolutions

Do you have a Cable and INPA?

I'd look at the rough idling section and look at the injectors.

Original injectors on an 08 is scary. You should replace all 6 just for peace of mind.

I'm getting INPA installed tonight and will report back. My buddy just started having the same issue after updating to the most recent BEF, but I wouldn't say it's more than a coincidence.

I'm buying my clutch and flywheel to have that done, and injectors are next, but it's adding up big time.

Thanks for your input Jeff

[Jeff@TopGearSolutions]

Originally Posted by 335NJ

I'm getting INPA installed tonight and will report back. My buddy just started having the same issue after updating to the most recent BEF, but I wouldn't say it's more than a coincidence.

I'm buying my clutch and flywheel to have that done, and injectors are next, but it's adding up big time.

Thanks for your input Jeff

Mine as well do the coils too.

I did all 6 coils spark plugs and injectors at same time, difference was night and day. Valve cover and gasket was done too.

Walnut blasting is next, car almost has 50K.

These cars need proactive maintenance to stay running optimally. Most people wait for problems which is understandable.

The problem with this car however, is these codes sometimes don't tell the whole story. You really need to know these cars to diagnose them correctly.

[msjt]

Leaking injectors won't necessarily show any codes. They are the cause of most idle and start up problems.

[335NJ]

Originally Posted by msjt

Leaking injectors won't necessarily show any codes. They are the cause of most idle and start up problems.

Absolutely agree, usually from fuel leaking into the cylinder when the engine is off, upon start up, it'll misfire. In my case I have no misfire (yet), but i'm certainly not ruling out the injectors until I run INPA and get a better look.

[ferocity02]

2DC3 and 2E8D are signs that your battery is dying. I would fix that first. Honestly, it's probably not the cause of this issue, but a dying battery on these cars causes all sorts of weird issues. I would start there, you need to regardless.
Time for some googling while I wait to see what you guys have to think.

Otherwise, I would do a log and see what is fluctuating during the dips. For example, you might find that fuel pressure is dropping which would indicate a fuel pump issue.

[335NJ]

Found this on the MAP sensor that leads into the top of the intake manifold. Possible suspect

[ferocity02]

Originally Posted by 335NJ

Found this on the MAP sensor that leads into the top of the intake manifold. Possible suspect

If the conductor part of the wire is in tact (looks like it is) then that's probably not the issue. It it was losing connection then I almost guarantee you would get a code. None the less, fix it before moving on.

[335NJ]

Originally Posted by ferocity02

If the conductor part of the wire is in tact (looks like it is) then that's probably not the issue. It it was losing connection then I almost guarantee you would get a code. None the less, fix it before moving on.

I'm hoping there's a "pigtail" style harness I can buy to cut splice and solder the new connector in, and wrap it in harness wrap. I don't wanna just put electric tape on it, especially a car like this.

Appreciate the input!

[Fast35i]

Originally Posted by 335NJ

I'm hoping there's a "pigtail" style harness I can buy to cut splice and solder the new connector in, and wrap it in harness wrap. I don't wanna just put electric tape on it, especially a car like this.

Appreciate the input!

Im currently having the same issue on my 335is at 30k miles I heard that a walnut blasting will correct the problem. Don't know if that's really true.

[335NJ]

Originally Posted by Fast35i

Im currently having the same issue on my 335is at 30k miles I heard that a walnut blasting will correct the problem. Don't know if that's really true.

Walnut blast can absolutely help smooth a rough idle if your valves are caked up. I had mine done about 10k ago.

[Fast35i]

Originally Posted by 335NJ

Walnut blast can absolutely help smooth a rough idle if your valves are caked up. I had mine done about 10k ago.

The idle got bad after I installed an after market cp and dci ,that's when I notice the up and movement I think it's cause by oil corrosion.. I'm definitely getting the walnut blast done next week

[335NJ]

Originally Posted by Fast35i

The idle got bad after I installed an after market cp and dci ,that's when I notice the up and movement I think it's cause by oil corrosion.. I'm definitely getting the walnut blast done next week

Is your MAP sensor fully seated in the new CP? Good seal on the TB from the new pipe?

[Fast35i]

Originally Posted by 335NJ

Is your MAP sensor fully seated in the new CP? Good seal on the TB from the new pipe?

I used the screws from the factory charge pipe on the map sensor , do u think I should've used the screws that ER supply with their cp instead ? I'll take a pic

[Fast35i]

Originally Posted by Fast35i

I used the screws from the factory charge pipe on the map sensor , do u think I should've used the screws that ER supply with their cp instead ? I'll take a pic

The er cp doesn't fit all way on the manifold theres a little gap