engine help > misfires

[5oh]

ok so the other day my m3 randomly started to drive like it was misfiring.

if i pushed the gas it would buck and putter.

then at a red light i turned the car completly off then restarted the car and it drove fine. i was like wtf?

it has done this about 3-5 times since ive owned it. this car is driving me crazy!

any help?

i was going to replace the spark plugs and see if that helps

[Ron97M3]

ok so the other day my m3 randomly started to drive like it was misfiring.

if i pushed the gas it would buck and putter.

then at a red light i turned the car completly off then restarted the car and it drove fine. i was like wtf?

it has done this about 3-5 times since ive owned it. this car is driving me crazy!

any help?

i was going to replace the spark plugs and see if that helps

When was the fuel filter changed? Air fiilter changed?

Check Engine light? What are the codes

How many miles on the car?

The service history related to engine things would help.

[Balthazarr]

Check plugs, coils, O2 sensors, coil boots, injectors (put some chevron gas into the tank, in fact, do this before anything else)

Crank sensor.

[Moron95M3]

all those^^ and one really simple one - air cleaner?? maybe fuel pump, but from how mine went, it's not as occasional. engine needs air, fuel, spark, and it's not getting one of them...

[Ron97M3]

all those^^ and one really simple one - air cleaner?? maybe fuel pump, but from how mine went, it's not as occasional. engine needs air, fuel, spark, and it's not getting one of them...

I agree ... actually not one very well some of the time in this case.

Because it comes and goes ... I am thinking it's a really dirty fuel filter perhaps.

To be that dirty it might need to be 150,000 miles with the original filter?

Anybody actually had a dirty fuel filter case a problem like this in a E36?

[Balthazarr]

I agree ... actually not one very well some of the time in this case.

Because it comes and goes ... I am thinking it's a really dirty fuel filter perhaps.

To be that dirty it might need to be 150,000 miles with the original filter?

Anybody actually had a dirty fuel filter case a problem like this in a E36?


Not a ff, but I have had bad gas in my bike before and it behaves similarly, albeit in a more exaggerated manner.

[fun2drive]

Lately I have had a stuttering in my car that is getting progressively worse. ICV is not the issue as this will happen when the car engine gets heat soaked like at a traffic light.

I have been through this before. My plugs (the good 4 electrode Bosch ones with 40K miles on them) have performed well and were replaced with the NGK model with no improvement which is what I expected.

I have ordered 6 new coils and 6 new boots. I have been through this before for my particular symptoms. These are Bremi coils and they are now 12 years old, actually according to the stamp they are 13 years old and have always been exposed to high heat from Florida.

The stuttering I am experiencing will soon grow to a miss at idle then a miss at acceleration.

Not sure this is what your issue is but after learning or should I say wasting a full summer chasing something like this 3 years ago with all the sensors, fuel pressure and volume test and on and on.

Bottom line is that unless you have a good diagnostic test equipment you can't test a coil at idle or measure ohms as you are just measuring the primary coil. A dynamic load is required and a MoDic machine can do this.

Just adding a suggest here that if your miss or stutter happens under load and is good at idle then don't overlook this area...

[Speedsta]

if you have a CEL get the codes pulled and see which cylinder(s) are misfiring, swap the plug to another cylinder and the coil to yet another a go drive it again.

if the misfire follows the plug, replace it.

if it follows the coil, replace it.

if it doesnt move, swap the injector and repeat.

and:
A dynamic load is required and a MoDic machine can do this.


MoDic's have been gone for years unless you know someone that bought on after BMW junked em probably 8 years or so ago. since then we've had the GT1 and now moved on to ISIS...

[fun2drive]

My experience is that you don't get a CEL unless the coil is dead and yes you are right there are some diagnostic machines rather then Modic II/III or GT1 that can read the coil under load.

This type of problem is one that is hard to diagnosis because one person's stutter is another person's miss.

The long running official hesitation thread is a great one to read because it covers virtually every contingency possible ....

[Kilijan]

I had a problem similar to that. When ever I filled the tank I would get misfires at 3k+ RPM and go into limp mode. Turned out to be the fuel tank pressure sensor that I hadn't moved over with my swap. Your best bet would be to get a code reader if you are getting a code. It will help others try and track down the problem remotely.