-SOLVED-
The issue was an extra o-ring in the crankshaft position sensor slot. This problem was persistent when I bought the vehicle and one of the first things I did was replace the crank sensor, but the one I pulled out had an o-ring on it so I didn't think to search for an o-ring that was stuck in the sensor slot before installing the new sensor. 2.5 years later and I finally found the issue. Now she runs like new and I know the SULEV swap was 100% successful! Cheers to you Fanatics!
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Yes, another one. This may be as simple as a malfunctioning MAF sensor or as difficult as a burned-out valve. If anybody is a GOD at interpreting data, I ask for your input here. To be direct, I believe it to be a failing MAF as I have noticed odd behavior in its reporting, such as sudden spikes and huge intake numbers (up to 60g/s at times). Confusingly, the vehicle idles very smoothly (3.3g/s warm) and the problem does not desist when the MAF is unplugged and the engine is running on the fixed fuel map. I have invested considerable time into this; I have closely read jfoj's cold weather misfire guide and performed nearly all of the work suggested in that thread. I have also completed nearly all of my originally planned engine restoration projects with the exception of the belts, pulleys, and tensioner yet the problem persists. Fortunately, there is a narrow margin of remaining possibilities and, with some help from the crew at e46fanatics, I am confident this discussion will come to a conclusive rest.
I'll do my best to be thorough & succinct. If you need any additional information on anything I write here go ahead and let me know and I'll get it for you. I have a large amount of stored diagnostic data but can always grab more. I have read hundreds of threads from a dozen different forums and found little useful information or actual data. Therefore I have created this thread in an effort to solve this issue and create information to be accessed by people whose paths bring them along this crossroads.
Vehicle: 2003 325ci m56b25 automatic with 230k on odo. Several systems on the vehicle have been reconstructed, which I will elaborate more on later. Not much of the systems that originally made this vehicle a super-low emissions vehicle (SULEV) remain. These systems have been replaced with compatible or equivalent systems from m54 coupe.
A couple of important things to note:
1. m56 stainless steel fuel system has been replaced with 5 bar fuel system from e46 M3 (-rail & injectors).
2. fuel pressure test valve has been installed at the fuel rail and measures steady 70psi (5 bars) at idle and speed.
The engine can experience jerking and misfires at any rpm. This has been persistent through all the repairs over the past 2 years I have owned the vehicle. These symptoms are extremely rare at idle, but when the rpm begins to rise past 2k the engine noticeably hesitates and loses power. Often, the battery light will flicker on and off again during these engine palpitations. The faster the engine goes, the worse the problem becomes. The engine will totally fail to rise past 5k rpm, and I daren't force it to. If I press the accelerator to the kick-down position, the engine jerks back and forth massively and I experience total power failure.
At highway speeds of 80 mph and an engine rpm of about 2.5k, I notice the engine misfire once or twice every minute. At speeds under 60mph and rpm under 2.5k, the symptoms do not manifest often and the car is perfectly fine to drive around town. These issues are very easy to manage by maintaining a low engine speed, and the car has been daily driven in this condition for at least 2 years. Perhaps unrelated, the engine often requires 2 cranks to start. These problems are especially prevalent while the engine is still cold, and are far worse. The engine starts to experience these problems less and regain a fair bit of power once the engine is warm.
Here I will briefly go over the notable work I have done on the engine.
1. Rebuilt the entire evap system.
2. SAP & Post-Cat 02 delete w/ ms54.1 euro tune.
3. Super Sprint headers & backpressure test.
4. ECU electrical repair.
5. Vanos seals & rings; solenoids checked.
6. Disa valve & O-ring.
7. All intake vacuum hoses have been plugged.
8. New CCV cap & diaphragm.
9. All hoses checked for cracks and seal.
10. New coolant thermostat & ambient air temp sensor.
11. Valve cover gasket replaced.
12. New spark plugs; coils swapped.
13. Compression test; cyl 1-5 170psi, cyl. 6 160psi .
14. ICV and throttle body tested to function.
15. 5 bar fuel pump & fuel pressure reg., fuel filter, plastic fuel tank (M3).
CEL is not on. Codes read misfire in all bank 2 cylinders. Engine idles smoothly with no issues. A few small things to note: The problem is very bad when the engine is cold but subsides significantly after being driven for a few minutes; idle to temp doesn't seem to do much. What's more, easing slowly off the pedal after kicking down reduces the effect. As noted earlier, compression and fuel pressure seem a-ok.
Below is some of the data I've compiled based on the document in this thread here. I have done my best to gather the data in the manner requested. I have mountains of this stuff, so please feel free to ask for any data comparisons or custom data charts you wish. The data is in ~5 min. intervals and goes as follows: cold start, steady highway speed, and warm idle, followed by a diagnostic report w/ freeze frame. I have also included some data comparisons that I think may prove useful. Lastly, I have a short video of the problems themselves as they manifest on the dash in my car. Hopefully, the information here will provide some much-needed support to a struggling e46 and its owner, and help bring this issue to a conclusive end for everybody. Thank you.
CSV not allowed here. Here's a link to the Dropbox Folder!
The issue was an extra o-ring in the crankshaft position sensor slot. This problem was persistent when I bought the vehicle and one of the first things I did was replace the crank sensor, but the one I pulled out had an o-ring on it so I didn't think to search for an o-ring that was stuck in the sensor slot before installing the new sensor. 2.5 years later and I finally found the issue. Now she runs like new and I know the SULEV swap was 100% successful! Cheers to you Fanatics!
-----------
Yes, another one. This may be as simple as a malfunctioning MAF sensor or as difficult as a burned-out valve. If anybody is a GOD at interpreting data, I ask for your input here. To be direct, I believe it to be a failing MAF as I have noticed odd behavior in its reporting, such as sudden spikes and huge intake numbers (up to 60g/s at times). Confusingly, the vehicle idles very smoothly (3.3g/s warm) and the problem does not desist when the MAF is unplugged and the engine is running on the fixed fuel map. I have invested considerable time into this; I have closely read jfoj's cold weather misfire guide and performed nearly all of the work suggested in that thread. I have also completed nearly all of my originally planned engine restoration projects with the exception of the belts, pulleys, and tensioner yet the problem persists. Fortunately, there is a narrow margin of remaining possibilities and, with some help from the crew at e46fanatics, I am confident this discussion will come to a conclusive rest.
I'll do my best to be thorough & succinct. If you need any additional information on anything I write here go ahead and let me know and I'll get it for you. I have a large amount of stored diagnostic data but can always grab more. I have read hundreds of threads from a dozen different forums and found little useful information or actual data. Therefore I have created this thread in an effort to solve this issue and create information to be accessed by people whose paths bring them along this crossroads.
Vehicle: 2003 325ci m56b25 automatic with 230k on odo. Several systems on the vehicle have been reconstructed, which I will elaborate more on later. Not much of the systems that originally made this vehicle a super-low emissions vehicle (SULEV) remain. These systems have been replaced with compatible or equivalent systems from m54 coupe.
A couple of important things to note:
1. m56 stainless steel fuel system has been replaced with 5 bar fuel system from e46 M3 (-rail & injectors).
2. fuel pressure test valve has been installed at the fuel rail and measures steady 70psi (5 bars) at idle and speed.
The engine can experience jerking and misfires at any rpm. This has been persistent through all the repairs over the past 2 years I have owned the vehicle. These symptoms are extremely rare at idle, but when the rpm begins to rise past 2k the engine noticeably hesitates and loses power. Often, the battery light will flicker on and off again during these engine palpitations. The faster the engine goes, the worse the problem becomes. The engine will totally fail to rise past 5k rpm, and I daren't force it to. If I press the accelerator to the kick-down position, the engine jerks back and forth massively and I experience total power failure.
At highway speeds of 80 mph and an engine rpm of about 2.5k, I notice the engine misfire once or twice every minute. At speeds under 60mph and rpm under 2.5k, the symptoms do not manifest often and the car is perfectly fine to drive around town. These issues are very easy to manage by maintaining a low engine speed, and the car has been daily driven in this condition for at least 2 years. Perhaps unrelated, the engine often requires 2 cranks to start. These problems are especially prevalent while the engine is still cold, and are far worse. The engine starts to experience these problems less and regain a fair bit of power once the engine is warm.
Here I will briefly go over the notable work I have done on the engine.
1. Rebuilt the entire evap system.
2. SAP & Post-Cat 02 delete w/ ms54.1 euro tune.
3. Super Sprint headers & backpressure test.
4. ECU electrical repair.
5. Vanos seals & rings; solenoids checked.
6. Disa valve & O-ring.
7. All intake vacuum hoses have been plugged.
8. New CCV cap & diaphragm.
9. All hoses checked for cracks and seal.
10. New coolant thermostat & ambient air temp sensor.
11. Valve cover gasket replaced.
12. New spark plugs; coils swapped.
13. Compression test; cyl 1-5 170psi, cyl. 6 160psi .
14. ICV and throttle body tested to function.
15. 5 bar fuel pump & fuel pressure reg., fuel filter, plastic fuel tank (M3).
CEL is not on. Codes read misfire in all bank 2 cylinders. Engine idles smoothly with no issues. A few small things to note: The problem is very bad when the engine is cold but subsides significantly after being driven for a few minutes; idle to temp doesn't seem to do much. What's more, easing slowly off the pedal after kicking down reduces the effect. As noted earlier, compression and fuel pressure seem a-ok.
Below is some of the data I've compiled based on the document in this thread here. I have done my best to gather the data in the manner requested. I have mountains of this stuff, so please feel free to ask for any data comparisons or custom data charts you wish. The data is in ~5 min. intervals and goes as follows: cold start, steady highway speed, and warm idle, followed by a diagnostic report w/ freeze frame. I have also included some data comparisons that I think may prove useful. Lastly, I have a short video of the problems themselves as they manifest on the dash in my car. Hopefully, the information here will provide some much-needed support to a struggling e46 and its owner, and help bring this issue to a conclusive end for everybody. Thank you.
CSV not allowed here. Here's a link to the Dropbox Folder!
