Misfire and clutch

Welcome back:

The knocking sound is most likely related to a release bearing issue. The only way to confirm is to remove it.
Is the compression 130 on all cylinders?

Let me know.

Joe

I just rechecked the compression and its 130 or so on all. when first started in the am mo clutch bearing sound and the car is 95% smooth and very minor misfire. here are the fuel trim numbers. I will report with the numbers again after she starts to misfire while idling, am starting to think maybe the injector? 72,000 miles though that usually isn't an issue.

Still no major misfire but here are the readings when warm:

Found this to not sure what it means. after i switched over injector 1 to 2, swapped, waiting to see if she will set the same code as cylinder one, once warm.

Sane code again number 1 but with number 2742.

Welcome back:

Bank 1 is overcompensating for a lean mixture. What all have done to check for a vacuum leak? Are you certain there are no exhaust leaks pre cat on bank 1.

Let me know

i thought this car only has one bank since it's inline 6.

just did a vacuum leak test and saw nothing.
All cylinders have 130 psi or for
plugs and coils are okay.
With the scanner turning injectors off while engine is running causes a change, including number 1., and that is when the car is warm and hardly misfiring (5%misfire felt).
Intake boots look okay.
Swapping injectors causes no change in the #1 misfire.
The misfire is worse after 30 minutes of idle especially when the throw out bearing knocking noise surfaces.
Takes that long going from pretty smooth idle to check engine light coming on and the knocking for that to happen.
Is it possible the knocking from throw out bearing putting a stress on the motor and hence causing the misfire?

Welcome back:

You know, and this is a long shot, I wonder if the noise is causing an issue with the crankshaft position sensor., Think about it, if it is banging on the crankshaft via the clutch, it could be causing an erratic signal from the sensor. I have no idea if you have an oscilloscope to test the signal from the sensor. However, if you do, here are the directions and what you should expect to see. I have no idea how bad the knock is you hear, but it could even be related to the crankshaft thrust bearings which commonly wear out faster with a manual transmission. In addition to the test below, check the crankshaft at the harmonic balancer for excessive end play.

Here are the directions I mentioned. The attached pics correlate with the directions.

__________________________

2004 BMW 525 (E60) L6-2.5L (M54)
Set Oscilloscope Display Crankshaft Sensor [FUB-SOW-FIN0201SO47TU001 - V.4]
Vehicle Powertrain Management Sensors and Switches - Powertrain Management Sensors and Switches - Computers and Control Systems Crankshaft Position Sensor Testing and Inspection Oscilloscope Patterns and Waveforms Set Oscilloscope Display Crankshaft Sensor [FUB-SOW-FIN0201SO47TU001 - V.4]
SET OSCILLOSCOPE DISPLAY CRANKSHAFT SENSOR [FUB-SOW-FIN0201SO47TU001 - V.4]
Functional description
Set oscilloscope display crankshaft sensor
FUB-SOW-FIN0201SO47TU001 - V.4

Signal at idle:

Pic 1

Signal at starting speed:

pic 2

Let me know what you find

Joe

can that be done using a scanner? if not then no i do not have one.i will check the harmonic balancer for sure, the thing about thrust, well, i doubt, because the noise goes away when i press the clutch deal, so definitely a clutch issue correct?

If it goes away when you depress the clutch, that would be my first suspect.

So what would be my next move here?

Car acting crazy, after i installed the injectors back it runs the same, but i have an o2 code now.

And sometimes these codes:

Welcome back:

The codes indicate a misfire and an issue with fuel mixture. Are you sure the O2 sensor is properly installed and the connection is proper? Was it a bank one sensor? Can you provide me the short term fuel trims so I can see what is happening?

Let me know.

Joe

i didn't even disconnect the wires for the o2 sensors, just did lay them on the side to get to the injectors, weird, and they have different lengths so am sure they are okay. I will get the readings for the fuel trims tomorrow.

Sounds like a plan. Let me know what you find.

Joe

I took it to the dealer hoping they can find something. i told them i have already swapped coils plugs injectors, so what did they do? Did the same thing and found nothing and want to charge me $188.00 for that, and want $461.00 to do a leak down test. i told them never mind. the service manager suggested i do a leak down test. is that different than the compression test i did?

They just gave me a sheet with couple of things, dme: misfire cylinder 1, and dme: fuel trim, bank 1, both present.

Can you tell me what the fuel trim are? That will help point me in the right direction.

As far as the leak down, they do a compression test differently? Rather than having the engine produce the pressure, a leak-down test relies on an external supply of compressed air which is injected into one cylinder at a time.

Joe

Here are the numbers you requested and more, at optimal engine temperature.

Attached.

Welcome back:

The computer is trying to adjust bank 1 to compensate for a lean mixture. The STFT should be close to 0 and the positive (high) number indicates it's allowing the injectors to stay open much longer than normal which is most likely the cause of issues on bank 1. Are you certain there are no vacuum leaks or even an exhaust leak pre catalytic converter?

Joe

I will double check again.

Let me know what you find.

Take care,
Joe

Nothing. If i remove the harness to the MAF sensor i saw a code for it plus one for the intake air temperature sensor, but i don't have one on this engine. Cleaned the MAF and put it back and plugged it. Do these readings look right? The engine is up to normal temperate. Also after clearing the codes i have none now but the oxygen sensor before catalytic converter bank 1 code is present.

And i just checked the values on the oxygen sensors. do these look right?

Welcome back:

It is based on how long the vehicle was running. They can go up to about .9v with a rich mixture when cold but should level out to aprox .45v when at operating temp.

So, one of the pics is higher than the other. If that was before warm up, no problem. The other is really close to normal, which should be after warmed up.

I hope this helps.

Take care,
Joe

As i indicated the engine was fully warm. i also noticed that one at 4.5v and the graph also shows that it sometimes move and others its solid line.

replaced the bank 1 before cat oxygen sensor and now reads 1.3 just like bank 2 before cat, and both after cat reading around .7, so far so good, crossing fingers, if that doesn't fix it i assume this was one of the issues, because the oxygen sensor is real black and was reding 4.5v all along, i just don't know why they reading 1.4 and not in the range of .1-.9 while warm.

Welcome back:

It sounds like you found the problem. Let me know if things change.

Take care and have a good weekend.

Joe

Drive it since yesterday and no issues. went to clean it up left it running for 2 hours and then i started hearing that noise from the throw out bearing and i knew then check engine would come on. it did, and it was misfire on 2, 3, and 4, doesn't make sense. now I am thinking this knocking noise is throwing off the knock sensor, no other explanation, o2 volts still good, I delete the code and this knocking sound goes away.

Welcome back:

Is it possible for you to record the sound so I can hear it? Also, when you delete the code, does the noise go away?

Joe

I will record it, when i delete the codes and restart everything is normal, no noise.

Welcome back:

Interesting. So, we get a mechanical noise from an electronic device. I will watch for your reply. I would like to hear it.

Joe

The noise is in the throw out bearing i assume because it goes away when i press the clutch pedal, so not electrical device, mechanical yes, i forgot to do it today, will do tomorrow.

Okay, now I understand. I thought you meant that when the code was deleted, so was the sound.

I will watch for your reply.

Take care,
Joe

Yes that too, i have worked on many BMW's never seen such thing before.

I have to be honest, I haven't either. That's why I am so interested in hearing it. Wish I was there to work on it with you. That would make things easier on me. LOL

Take care and I will watch for your reply,

Joe

I know, if the noise didn't go away with the pedal pressed. i would have thought its knocking, and the crazy thing which that the noise goes away after the misfire codes are deleted.