[Al535e34]

Hi everyone, I’m new to the forum but long time BMW owner and wrencher.

I’m stumped with a 2006 3.0si n52 Z4 with 85k with misfire Cyl 4 & mixture to rich Bank 1 for now. Had Bank 1&2 but Bank 2 resolved after replacing a broken intake rocker eccentric arm.

Been through many troubleshooting but the misfire on 4 hasn’t changed. List includes the following:
1. Swapped coils around
2. Replaced plugs (2x) - platinum then back to iridium
3. Smoke test - found upper CCV hose cracked
4. CCV replacement (hoses and unit)
5. Injectors replaced with remanufactured ones
6. Upstream O2 Front/back replaced
7. MAF replaced with Continental MAF (replaced with a cheap one originally)
8. Checked/cleaned Vanos solenoids
9. Checked & Cleaned idle valves (2 small filter like on side of engine front - they were clean)
10. valvetronic unit tested including wiring from computer side
11. DISA valves replaced x2
12. Found broken rocker ecentric arm on Cyl 4 & replaced it
13. Replaced valve cover gasket, torqued to spec with new screws
14. Replaced oil filter housing oil & coolant gaskets
15. Compression tested which Cyl 4 was higher by about 10% (before replacing eccentric arm)
16. Reset adaptation & cleared codes what seems like 100 times
16. No blue smoke on startup
17. MAF connector was replaced early on
18. Tested wiring from ECU to coils, valvetronic and
Injectors, no issue
19. Tested voltage to ground for injectors and all seemed ok



I have INPA and cylinder 4 when running hard, is ok, else it can go to the 4-7 range. No lack of power and the original sputtering at start went away after replacing the eccentric arm.

I’m tired of throwing parts at it but I’m in the middle of trying to clean the post cat O2s and was thinking to replace them.

Obviously I have put a ton of money and time into it and just want it to run right and pass emissions as tags have expired. Any help would be greatly appreciated as I’m beyond frustrated with all the work done and no to little change especially the misfire on Cyl 4

Thanks,
Al

[gbalthrop]

Originally Posted by Al535e34

... 2006 3.0si n52 Z4 with 85k with misfire Cyl 4 & mixture to rich Bank 1 for now...
I have INPA and cylinder 4 when running hard, is ok, else it can go to the 4-7 range. No lack of power and the original sputtering at start went away after replacing the eccentric arm...Al

Welcome to the Forum, Al !
I would suggest posting INPA ScreenPrints, beginning with the two Functional Jobs ScreenPrints in attached "INPA Tutorial Quickstart":
1) INPA > Functional Jobs > F2 Identification (so we can see Variant/SGBD of EACH of your Modules);
2) INPA > Functional Jobs > F4 > F1 Read Fault Memory, ALL Modules;
3) INPA > DME (MSV70 or MSV80?) > F4 Error Memory > F3 Read Error Memory With Freeze Frame Data (MOST Details).

I presume you have 29D0 Misfire Cylinder #4 & 29E0/P0172 Bank 1 too Rich? We want to see Freeze Frame Data & Fault Details for BOTH of those codes. We can then view Live Data (F5 Status) and perhaps do F6 > F1 Injector Activations, or F9 > F2 Fade Out Injector. Have you viewed "Rough Running" screen: INPA > DME > F5 Status > F7 Rough Running

Please let us know if you also have ISTA, as that can do some different tests, such as Injector Pulse duration.

Questions:
Last-7 Characters of VIN?
Currently SES is ONLY warning light?
Do 29D0 & 29E0 ALWAYS appear together in Fault Memory at SAME mileage? Do you FEEL any rough running from Injector Cutout (running on 5 of 6 cylinders) when misfire occurs?
Or does engine perform ~ normally even when misfire & SES Light?
What about WOT acceleration in 1st > 5,000 RPM?
Does misfire seem to be intermittent, random, Engine-Temp related, RPM-related, etc.?
George

[Al535e34]

George,

Thanks in advance and I appreciate your help and patience while I get this info put together.

I really appreciate your reply! Took me a few days to get to put it back together after cleaning the post cat O2 sensors, and no major change other than now my Throttle and its adaptation is throwing an error that I never had before and the EML light is coming on. I'm suspecting a bus error as I notice when I turn the turn signal on, it clicks then stops while still blinking, and comes back and so on. Been dealing with this for a few years, but will stick to the issue on hand first unless it is related.

Originally Posted by gbalthrop

Welcome to the Forum, Al !
I would suggest posting INPA ScreenPrints, beginning with the two Functional Jobs ScreenPrints in attached "INPA Tutorial Quickstart":
1) INPA > Functional Jobs > F2 Identification (so we can see Variant/SGBD of EACH of your Modules);
2) INPA > Functional Jobs > F4 > F1 Read Fault Memory, ALL Modules;
3) INPA > DME (MSV70 or MSV80?) > F4 Error Memory > F3 Read Error Memory With Freeze Frame Data (MOST Details).

- Attaching screen shots. Labeling as follows F2 for item 1, F4_F1_rx_X where it is for error reads, multiple times. rx = cycle after reseting previous codes. X is # of error within the cycle. Hope this makes sense

Originally Posted by gbalthrop

I presume you have 29D0 Misfire Cylinder #4 & 29E0/P0172 Bank 1 too Rich? We want to see Freeze Frame Data & Fault Details for BOTH of those codes. We can then view Live Data (F5 Status) and perhaps do F6 > F1 Injector Activations, or F9 > F2 Fade Out Injector. Have you viewed "Rough Running" screen: INPA > DME > F5 Status > F7 Rough Running

Please let us know if you also have ISTA, as that can do some different tests, such as Injector Pulse duration.

Usually 29D0 with 2A2E (used to be both 2A2E & 2A2F)/P0172,P0175.

I look at F7 Rough running all the time which tells me how messed up my Cycl4 is. Will attach what I can here as far as screen prints.

Trying messing with F9>F2 and turned off Cycl 4 momentarly and it was running bad so turned it back on.

No ISTA, don't mind setting up, but will have to hunt for it first


Questions:
Last-7 Characters of VIN? LW91094
Currently SES is ONLY warning light? It's ON
Do 29D0 & 29E0 ALWAYS appear together in Fault Memory at SAME mileage? I would say yes, although 29D0 first then the 2A2E

Do you FEEL any rough running from Injector Cutout (running on 5 of 6 cylinders) when misfire occurs? No. After resetting adaptation and codes, car runs really good until the computer starts adjusting based on sensor input. Doesn't last too long unfortunatly

Or does engine perform ~ normally even when misfire & SES Light? Runs strong, no issue in performance
What about WOT acceleration in 1st > 5,000 RPM? Haven't tried but drove it over 5K rpm for extended periods to see if anything happens, but ran fine

Does misfire seem to be intermittent, random, Engine-Temp related, RPM-related, etc.? Seems like it to me

The 2 images were from before resetting and driving a couple of different cycles. Adaptation multiplier is definetly higher. Will grab a couple of screen shots and upload later today or tomorrow morning.




Updated F6 & F7. Also EML light went out as I restarted to move it but didn't have INPA ready. Check engine still on

F6.pdf
F7.pdf


F2.pdf

F4_F1.pdf

F4_F3_1.pdf

F4_F3_1_r1.pdf

F4_F3_2.pdf

F4_F3_2_r1.pdf

F4_F3_3.pdf

F4_F3_3_r1.pdf

F4_F3_4_r1.pdf

F4_F3_5_r1.pdf

[Al535e34]

I was finally able to do a leak down test on cylinder 4 and while I was at it, I did a leak down for all cylinders. Nothing found at least from what I know.

Engine was cold when I performed the test, put each cylinder at top dead center on the compression cycle and ran the test and all were under 10% including Cylinder 4 Hissing noise from the oil fill cap but nothing from exhaust, intake or from the coolant reservoir.

New plugs looked ok except for cyl 4 seemed to have a little oil on it. I'm really at a loss here.... Any help would be greatly appreciated.

[Al535e34]

Uploading the data in the pdfs as images hoping this helps

There are 2 different drive cycles that I have captured. I reset adaptation and codes after the first one and then the errors in cycle 2 came up.

F2 Data:


Cycle 1:
F4_F3





Cycle 2:
F4_F3






F6 Data:


F7: Data


Hope this can help shed some light

[Al535e34]

Bump..ulling my hair out with this one. Any help would be greatly appreciated. Any ideas to try. Thanks in advance

[NZE90]

When you replaced the "eccentric arm" did you match the number on the old arm with the new one?

[Al535e34]

Yes, it was same number 3 and have another spare one.

The bottom eccentric has a dome that sits on a bump (I know, my technical very specific terms ) but wondering if something is bent there, similar to bent push rods (not exactly sure)

[NZE90]

Maybe you should another compression test then. The valves are supposed to be in full lift when doing a compression test.

There's a service function in ISTA which puts the valves to full lift. Not too sure if INPA can do the same.