[A13E92]

Hi All,

Background:
'08 335i 6MT 73k
New plugs, less than 50 miles
New JB4 G5, less than 50 miles
No issues in map 5 except for occasional 30FF prior to vac line replacement

As it sits now:
No misfire
Smooth idle and engine revs when codes cleared
Immediately throws code as soon as I start driving
Harsh knocking sound and undriveable when under load
Persistent 2ABC and 3100 codes - Harsh idle with knocking/rattling sound until codes cleared
JB4 Map 0

More info
My vac lines had a slight leak by the oil filter so I went ahead and replaced them all with new Silicone hoses. When I put it back together, I had the hoses that go into the rear boost solenoid backwards somehow. I started up the car like that and it idled fine for five minutes before I took it out for a spin around the block. As soon as it started spooling my car went into limp mode and started shaking and making knocking sounds. Codes were for Cyl 3 misfire (29CF), and 2ABC (2ABC Charging pressure sensor, electrical) and 3100 (3100 low boost mode engaged -- CEL displayed).

I pulled spark plug 3 and it had a thin coating of what I believe is oil on it, so I put in an older spark plug and the misfire went away and the car idled fine. I pulled the plug again after letting it idle for a few minutes and it was completely dry. I'm not sure what that was all about. Coincidence or related...

The problem that had me really worried are the other two codes. I can't quite figure out what is causing it. I can rev the car just fine and everything seems normal, but as soon as I put load on it, it throws a half CEL and makes an awful rattle/knocking sound coming from the front of the car.

What should my next troubleshoot step be? What could have been damaged by mixing up the hoses on the one solenoid?

I appreciate the help!



Pictures:

Good Spark plug from Cyl 2



Spark plug pulled from Cyl 3

[MJ80.]

Hey dude. I had the exact same codes and half engine with limp mode on boost after my charge pipe install. My Tmap wasnt plugged in fully and was coming loose. I secured the tmap to the charge pipe better and the issue is resolved.

Check your tmap would be my suggestion.

[YoungBlood]

Do you have a daeos harness by chance? 3100 is thrown anytime there is a code that the DME cuts boost for

[V8bait]

You probably gave the turbos full vacuum and spiked the map sensor voltage safety with uncontrolled overboost. It was probably fun for a second or so. Fix the vacuum lines clear the codes and continue about your day.

[A13E92]

Originally Posted by YoungBlood

Do you have a daeos harness by chance? 3100 is thrown anytime there is a code that the DME cuts boost for

No Daeos harness.

Originally Posted by V8bait

You probably gave the turbos full vacuum and spiked the map sensor voltage safety with uncontrolled overboost. It was probably fun for a second or so. Fix the vacuum lines clear the codes and continue about your day.

That's what I'm hoping, but every time I clear the codes via Carly and JB4 they came right back on.

Originally Posted by MJ80.

Hey dude. I had the exact same codes and half engine with limp mode on boost after my charge pipe install. My Tmap wasnt plugged in fully and was coming loose. I secured the tmap to the charge pipe better and the issue is resolved.

Check your tmap would be my suggestion.

I double checked the TMAP sensor on the charge pipe and the other one on the manifold. They both were seated fine since I've never messed with them but I sprayed them with MAF cleaner, reseated the sensor and the harnesses. I also unplugged the battery for a couple hours to totally reset the computers since it did look like an electrical fault. Car made the knocking noise again when I started the car but went away after a minute. I got it out of the driveway fine and took it around the block with no issues. Will report back to see if the above fixed my issue!

Thanks for the advice guys!