[dane_c21]

I need some help determining whats wrong with my E92. Car will cold start and idles/revs just fine. Then you put it under load, it just has no power,/limp mode and eventually stalls out and then struggles to restart. Ive replaced all spark plugs and coil packs, thinking it was an ignition issue, no luck. Then i replaced both VANOS exhaust and intake valves, eccentric valve timing motor and sensor, thinking it was a timing issue, still no luck. Then i replaced the starter ( i can assume unrelated, but stalling so much and having to restart the car mustve fried my starter) and lastly ive replaced the valve cover, also unrelated, but it was leaking. Just providing as much info as i can. I ran the codes, and it said cylinder 1,2&3 misfire, multiple misfire, camshaft position timing over retarded bank1.

I took it to the BMW dealership and after $300 for some ridiculous diagnostic fee, they said the leak down test was within range. All they could come up with was a clogged catalytic converter and "it revved up just fine when they disconnected the exhaust". So after towing it home and removing the exhaust myself to confirm the issue, it did start, idle, and rev normally. Until i shift into first and put load to the wheels. Back to the same issue of not even enough power to make it up the driveway.


I need some help here, cant trust the dealer and obviously dont want to keep throwing money at this issue.


2007 328i E92 Coupe. 6sp trans.

[JonOhh]

Initial thoughts:

Does it run fine within the first 30 seconds or so of running, even under load? Since it's one bank, I am inclined to think it is either an oxygen sensor or ground for the bank one electronics (coils and such). I believe coils 123 and 456 have separate grounds.

What happens if you unplug the oxygen sensors? I've never done such on a BMW, so this could be absolutely horrible advice (obviously very temporary for diagnosis), but this is what I'd do.

[JonOhh]

Also, will it do a WOT rev (about idle to 4000rpm with the pedal on the floor) cleanly when at operating temp, yet absolutely fall on its face under a light load acceleration?

Do a rev with the clutch in and clutch out while in neutral. The engine behaves differently based on clutch position, something with throttling method (valvetronic vs throttle body) it would be good to determine if the issue is identical in both clutch positions.

[dane_c21]

Originally Posted by JonOhh

Initial thoughts:

Does it run fine within the first 30 seconds or so of running, even under load? Since it's one bank, I am inclined to think it is either an oxygen sensor or ground for the bank one electronics (coils and such). I believe coils 123 and 456 have separate grounds.

What happens if you unplug the oxygen sensors? I've never done such on a BMW, so this could be absolutely horrible advice (obviously very temporary for diagnosis), but this is what I'd do.

I would probably say it's fine for the first 10 seconds under load from a cold start, but by the time I get to around 4K, it's running terrible again.

I haven't tried unplugging the o2 sensors yet.

And at WOT it falls flat. Only way to save it from stalling is to press the clutch in.

[JonOhh]

So it falls flat even in neutral? Try the revs in neutral with clutch up and then down, and report back if there's any difference.

Also very interested to see what disconnecting the o2 sensors does. They aren't used for the first few seconds (actually a bit longer) of engine running, but obviously revving the crap out of a cold engine is never good, so just disconnecting them allows you to eliminate them as an issue when at operating temperature.

[dane_c21]

Originally Posted by JonOhh

So it falls flat even in neutral? Try the revs in neutral with clutch up and then down, and report back if there's any difference.

Also very interested to see what disconnecting the o2 sensors does. They aren't used for the first few seconds (actually a bit longer) of engine running, but obviously revving the crap out of a cold engine is never good, so just disconnecting them allows you to eliminate them as an issue when at operating temperature.

Sorry if I was unclear. I was saying with the clutch engaged, revs fine.

[JonOhh]

Originally Posted by dane_c21

Sorry if I was unclear. I was saying with the clutch engaged, revs fine.

No worries.

[dane_c21]

Originally Posted by JonOhh

No worries.

I'll check the ground for 1-3 and also try disconnecting the o2 sensors tomorrow afternoon. I'll keep ya posted. Thanks for the help so far!

[mecheng77]

The dealer said your exhaust is clogged, isn't that the route cause?

I would clean all your grounds, the one under the car especially.

[gbalthrop]

Originally Posted by dane_c21

... Car will cold start and idles/revs just fine. Then you put it under load, it just has no power,/limp mode and eventually stalls out and then struggles to restart... I ran the codes, and it said cylinder 1,2&3 misfire, multiple misfire, camshaft position timing over retarded bank1.

BMW dealership...said the leak down test was within range. All they could come up with was a clogged catalytic converter and "it revved up just fine when they disconnected the exhaust". So after towing it home and removing the exhaust myself to confirm the issue, it did start, idle, and rev normally. Until i shift into first and put load to the wheels. Back to the same issue of not even enough power to make it up the driveway...328i E92 Coupe. 6sp trans...it's fine for the first 10 seconds under load from a cold start, but by the time I get to around 4K, it's running terrible again...

When it loses power under load, is it running ROUGH or just acting like ALL cylinders are affected equally, as in NOT getting enough fuel? It appears you got "locked into" the idea that it was an ignition problem due to the "Misfire" Fault Codes for Cylinders 1,2,3 (Bank 1). If the lack of power under load were due to ignition issues on Bank 1, when it loses power, or is placed under load, it would be VERY rough as compared to ALL cylinders losing power on an approximately EQUAL basis.

Your post suggests that the Codes you saw were P0300, P0301, P0302 & P0303. HOWEVER, we should NOT assume that, as there are OTHER codes that indicate Injector Shutdown, so please post the Fault Code Numbers. ALSO, when you say "struggles to restart" after stalling, please describe what happens exactly. Does it crank longer than normal, sputter before starting, etc.? Once it starts does it idle smoothly, at least after 5 to 10 seconds?

It MIGHT be helpful to attach a Scan of the Dealer's invoice so we can see what was done and any reported test results. I would be particularly interested in knowing what they did & HOW to determine the Bank 1 Cat was clogged. Have you previously had any SES light on the dash and any Misfire codes or Rich Running Codes (P0172/29E0 or P0175/29E1)?

Do you have a Scan Tool or Diagnostic Software that is capable of reading Fault Codes in the EKPS (Fuel Pump Module)? Please identify any such Tool/ Software you have available. Can it do Activation of the Fuel Pump or Read Parameters such as RPM, Setpoint, and Temperature in the Fuel Pump (EKP)? If not, and if you have a Windows Laptop, you should consider spending $45 for a BimmerGeeks K+DCAN Cable and Downloading "BMW Standard Tools" which includes INPA Diagnostic Software. That can test Fuel Pump operation, Fuel Injector operation, and read Fault Codes and Freeze Frame Data/ Fault Details, in ALL Modules. It will take a few hours to install and learn how to use INPA, but quicker/cheaper than throwing parts.

If you have a pressure gauge that you can attach to the "Schrader Valve" on the Fuel Rail, that will allow you to read Rail Pressure in real time. That could be problematic trying to read pressure under load, but better than nothing.

George

[dane_c21]

Originally Posted by JonOhh

So it falls flat even in neutral? Try the revs in neutral with clutch up and then down, and report back if there's any difference.

Also very interested to see what disconnecting the o2 sensors does. They aren't used for the first few seconds (actually a bit longer) of engine running, but obviously revving the crap out of a cold engine is never good, so just disconnecting them allows you to eliminate them as an issue when at operating temperature.

Unplugged the top 2 o2 sensors. Didn't wanna start up at all. Wasn't the ground wire either.

[dane_c21]

Originally Posted by gbalthrop

When it loses power under load, is it running ROUGH or just acting like ALL cylinders are affected equally, as in NOT getting enough fuel? It appears you got "locked into" the idea that it was an ignition problem due to the "Misfire" Fault Codes for Cylinders 1,2,3 (Bank 1). If the lack of power under load were due to ignition issues on Bank 1, when it loses power, or is placed under load, it would be VERY rough as compared to ALL cylinders losing power on an approximately EQUAL basis.

Your post suggests that the Codes you saw were P0300, P0301, P0302 & P0303. HOWEVER, we should NOT assume that, as there are OTHER codes that indicate Injector Shutdown, so please post the Fault Code Numbers. ALSO, when you say "struggles to restart" after stalling, please describe what happens exactly. Does it crank longer than normal, sputter before starting, etc.? Once it starts does it idle smoothly, at least after 5 to 10 seconds?

It MIGHT be helpful to attach a Scan of the Dealer's invoice so we can see what was done and any reported test results. I would be particularly interested in knowing what they did & HOW to determine the Bank 1 Cat was clogged. Have you previously had any SES light on the dash and any Misfire codes or Rich Running Codes (P0172/29E0 or P0175/29E1)?

Do you have a Scan Tool or Diagnostic Software that is capable of reading Fault Codes in the EKPS (Fuel Pump Module)? Please identify any such Tool/ Software you have available. Can it do Activation of the Fuel Pump or Read Parameters such as RPM, Setpoint, and Temperature in the Fuel Pump (EKP)? If not, and if you have a Windows Laptop, you should consider spending $45 for a BimmerGeeks K+DCAN Cable and Downloading "BMW Standard Tools" which includes INPA Diagnostic Software. That can test Fuel Pump operation, Fuel Injector operation, and read Fault Codes and Freeze Frame Data/ Fault Details, in ALL Modules. It will take a few hours to install and learn how to use INPA, but quicker/cheaper than throwing parts.

If you have a pressure gauge that you can attach to the "Schrader Valve" on the Fuel Rail, that will allow you to read Rail Pressure in real time. That could be problematic trying to read pressure under load, but better than nothing.

George

It's running verrrry rough. And when I say it struggles to start, it cranks and cranks until I give it some throttle to keep it running, and once I stop pressing throttle it stalls out.