Hey all, been chasing a random misfire for too many weeks now. Here is short story:

Car is a 2004 545i with 170K, pretty extensive maintenance records.

Was driving to work one day, doing 40mph about 2 miles from home, approach a red light so I slow down and car starts stumbling/shaking and dies. Restart, still with stumbling and shaking but manage to get onto shoulder. I could restart it and it would die if I let it idle. So I restart and baby it home, car seemed to do better under load, definitely didn't like idling.

Pull codes and have misfires in all cylinders and "274E sumcheck error"

Clear codes and restart, car is not smooth and has a stutter and shakes, throws a SES light again. Misfire in cylinder 2,3,4 and sumcheck error. Do this process multiple times and the misfire will change cylinders, but it will be about 3 or 4 of them usually, sometimes 7 cylinders.

So new plugs and new coils. Same exact symptoms.
Checked CCV valves, good condition, no oil and good diaphragms. Did a smoke test with throttle open and didn't see any leaks.

Replaced MAF with new Bosch, same symptoms.

I checked fuel pressure at the rail at idle, gauge read 50psi, but it was soaking the rag (small leak from the Schrader valve) I had at the base, so I shut it down. Did the test a couple more times and same pressure.

I check the ohms on each fuel injector except for #4 and #8. I got 13.2 for the six I checked.

Pulled passenger side Vanos solenoids and cleaned them, ohmed them and put power to them. They are activating.

Tried a different crankshaft position sensor. Same symptoms.

You can always feel the misfire from the moment you start the car. If you stop it and restart it, the stumble/misfire does not go away. Recently when I started it and let it run, the stumble/shake starts out minimal (but definitely there) and gets worse, till it throws a code and then wants to die.

The misfire gets worse and car starts to stumble and would probably die.

No other codes except misfire.

I have a Creator 310+ code reader and INPA. I am not an INPA guru, but I noticed a couple of the "cylinder roughness values" being higher than the others.

Sorry, I said short story....Any ideas?

thanks in advance...

 

Very strange that's doing it on every cylinder, even after cold start. I would say get a "noid" light and check the electrical connectors at the fuel injectors themselves to ensure you're getting signal to the injectors. You have no vacuum leaks, good fuel pressure, and spark/coils then it may be an electrical issue.


This set came in handy. You would need to use the BOSCH PFI noid light.

 

Check your coil packs, and your cam Shaft intake sensors .

 

[QUOTE=545eyeballV8;1609898]
Check your coil packs, and your cam Shaft intake sensors . Also check your vvt Module located on the passenger side firewall under the hood for water damage .I had water in my vvt module .

 

[QUOTE=545eyeballV8;1609898]
Check your coil packs, and your cam Shaft intake sensors . Also check your vvt Module located on the passenger side firewall under the hood for water damage .I had water in my vvt module .

 

This maybe sounding like a strange “offthe. Wall” question but what oil are using?....
Your engine oil maybe too thin.
Reason for saying this is my experience with random misfires have been fixed by using 10W60.
Now to explain here in the North we got this problem with misfires with that 274E code on cold start only in winter and it took me eight seasons to finally eliminate the problem by putting a heavier oil. I used to regularly run the Europe version CASTROL 0W30 on all my BMW’s for 20 yrs and did so when I got the 545 and I ran across a forum post suggesting this and ran it that way for two winters and this last winter decided to push my luck and go down to 5W40 instead.....still good haven’t had any misfires on startup since.

your issue might different but if you run out ideas it just maybe worth a try and it’s cheaper than throwing parts at it to see what sticks!

 

Got a noid tester coming today.

Picked up a VVT module at a yard this morning.

I am using Mobil 1 5W-30 full synthetic. I remember reading your post about the oil weight (I feel like I have read all things E60 misfire). What gets me is it just randomly started doing it.

It is hard to feel the misfires when I give the car throttle. Really just seems to miss/cough/sputter at idle.

Will update...

 

I only see that on vacuum leaks mainly the breather hose

 

A leaky hose was the first thing that came to my mind as well, until I read that he did a smoke test.

 

Yea I read that too. Still not passing on it though