Strange problem @ 5000 RPM!

[rushan]

Hi All,

I have M44 1996/1997 1.9L engine....

in the last few days i notice that my car when it hit 5000/5500 RPM it start to ping ( cutting up ) exactly as what happen if it reach 6500 RPM.

if i keep the gas padal on it keep cutting up until it reach 6500 RPM.

this happen after while when the engine get worm but when engine still cold it work normally and ping ( cutting up ) normally at 6500 RPM with no problem.

there is no errors stored on my engine computer

so anyone know why this happen?

Regards
RmS

[dave45056]

Hmmm... could be the disa actuator. That engages around that rpm.

to be honest, I don't completely understand your question.
Pinging is usually a fuel problem. The M44 has knock sensors to prevent it.
so maybe it's not real pinging (predetonation) that you are hearing.
By the way, did you read the codes with a code reader? or are you saying no codes stored because the CEL is not lit?

[rushan]

ok i will try to explain this more

when I push on my car and it reach 5000 RPM it start cutting like it reach 6000 or 6500 redline limit... it start cutting from 5000 and it keep going up until it reach normal redline limit.

this appear only when the car warm and temp on middle. when the car still cold it run normally....

my scan tool show this errors

4 Idle Actuator ZWD Winding 1/EWD open circuit/earth short

0 unknown fault

0 unknown fault

[dave45056]

Well, I would start addressing the known problem your scan tool detected.
After that I would look for spark problemsCan you see arcing at night with the hood open at 5000+rpms? You may have to take off the spark plug cover to see. Are your plugs good? Wires? Any oil in the spark plug holes?
It is really hard to diagnose a problem like this... but if you have some basic knowledge about cars I would start with the basics of fuel, air and spark.
Also, if you find out anything more, post it here. There are a lot of knowledgable people on this site.

[rushan]

Thank you... yes i have basic skills and i checked everything... plugs are good and no arcing no oil leak...

about the error
4 Idle Actuator ZWD Winding 1/EWD open circuit/earth short

i'm trying to find whats the idle actuator ZWD winding exactly and where located...

here is a photo of engine ...



i know the TP sensor on left and IDLE REGULATING VALVE on right but where the Idle Actuator ZWD Winding located?

Regards

[ClubSport]

Try changing your fuel filter first, it's easy to do. If it's at 5000 rpm I doubt it's a problem with your idle actuator. Sounds fuel or spark related.

[cooljess76]

Behind your front passenger fender liner there's a grounding cable that connects to the engine mount and the chassis. Remove it and clean the ends thoroughly with a wire brush or sandpaper. Check it for continuity and for resistance with a multimeter and re-install it. That might clear the code for earth short. Of course you'll have to reset it with your code reader.

There's a good chance that at higher RPMs your alternator is producing too much power or not enough and if the main engine ground doesn't have a good connection, it will short out and arc against the chassis. Atleast that's what happened to mine. I don't regularly go over 5000 RPMs, but I had a similar problem with my car. Good Luck!

[aceyx]

It sounds as if the problem he's describing is similar to the rev-limiter, except that it happens at 5k RPM. That is, the needle bounces around?

According to the following document:
http://www.bmwclub.lv/files/Tab_3_M54_Engine_X5.pdf (page 45)
The idle speed actuator is the idle air control valve. It reads as if your problem occurs when the valve is stuck in the open position.

There are plenty of threads on here about cleaning the ICV, theoretically that should solve your problem.


Also, NEVER rev above 3k if the motor isn't warm. ALWAYSALWAYSALWAYS warm up a motor before flogging it.

[bmw318is1994]

Can you get a camera by chance and record your tach/sound that it's doing so we can all get a better idea? plz make sure you let your car get WARM first. That has bad ju ju written all over it if you continue to wrap it out that high without being full warm.

[rushan]

ok i will record the sound and the rpm tomorrow @ daylight. and post it here

[rushan]

Hi,

here is 2 clips ,,, hope its clear enough to hear the sound...

try to notice the sound when its 5000 - 5500 RPM up until it reach 6500 rpm , its doing the sound of the rev-limiter , it start from 5000 - 5500 keep going up until 6500 redline and stop on the real rev-limiter

http://195.158.192.1/rms/MOV00011.3gp

http://195.158.192.1/rms/MOV00012.3gp

[b.u.ti-ful]

I watched the video, but I couldn't make out any problems with the sound.

Can you buy higher octane gas where you are?

Might be worth a try.

[rushan]

if you lsn carefully you will notice between 5000 up to 6500 its like sound of the rev-limiter.

I use unleaded with 95 Octane and usually I add octane booster on full tank. so its 98 octane!

this issue start to show recently only ... same gas same everything

[b.u.ti-ful]

If you think the gas is good and the spark is good and the injectors are clean, I'll have to say change the fuel filter.

[rushan]

Hi thanks for the Help and hints

well if its fuel filter why it only show after the engine get warm and heat @ middle about 2 - 3 min after drive or turn on. it doesnt happen when the car engine littel cold. my filter replaced year ago.


anyways here is more clear video on the sound and RPM

http://195.158.192.1/rms/MOV00013.3gp
http://195.158.192.1/rms/MOV00014.3gp
http://195.158.192.1/rms/MOV00015.3gp