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nabilc
nabilc,
Category: BMW
Satisfied Customers: 3498
Experience:  Manager/co-owner at Autotronic
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2004 x5 3.0 cyl 6 misfire at all time swap coils plugs

Customer Question

2004 x5 3.0 cyl 6 misfire at all time swap coils plugs injectors.... compression 155-160 across leak down less 5% all cyls...also replaced intake gaskets ???
Submitted: 1 year ago.
Category: BMW
Customer: replied 1 year ago.
Posted by JustAnswer at customer's request) Hello. I would like to request the following Expert Service(s) from you: Live Phone Call. Let me know if you need more information, or send me the service offer(s) so we can proceed.
Customer: replied 1 year ago.
disa valve not broken.....
Expert:  nabilc replied 1 year ago.
Hello and Welcome! I'm Billy and i will assist you with your inquiry. Feel free to ask if any further info is needed.
My apologies for the delay, thank you for your patience.
are you getting injector pulse, and spark on cylinder 6?
did you check the wiring from the injector, and coil to the DME?
Customer: replied 1 year ago.
I am getting injector pulse and spark but of course PCM shuts down the injector when it recognizes the misfire
Expert:  nabilc replied 1 year ago.
Hello,
Indeed the DME will shut down the injector when a p0306 is triggered.
Would you be able to check the wiring integrity, or at least the connectors (make sure you have tight and clean contacts) on the cylinder and on the DME (PCM)?
Customer: replied 1 year ago.
Talking on the phone would probably be better
Expert:  nabilc replied 1 year ago.
Hello again,
I'm afraid that i'm unable to speak on the phone due to shop noises. If you wish, i can continue assisting you like this, or i can opt out, so other experts take a look at this.
Regards,
Billy
Customer: replied 1 year ago.
Injector pulse and spark are fine I did a running compression test cyl 6 just made the needle flutter slightly the rest of the cylinders were as expected recheck compression on cylinder number 6 at first I had 0 recheck cylinder number 5 had 155 recheck cylinder number 6 155 I don't know if this could be of a vanos problem I don't know if that can affect only one cylinder I ran the engine with the exhaust solenoid disconnected the Miss wasn't as pronounced but would still set 243 code my data list with engine running show cylinder number six week at 1.43 the rest of the cylinders are at 0.01
Expert:  nabilc replied 1 year ago.
Hello again,
This does not sound like a Vanos problem, it usually does affect more than one cylinder, or at least the misfire will travel from cylinder to another.
Having the needle fluttering, and getting 0 compression at one time, is an indication of a compression problem.
However, i would first check for vacuum leaks, and check the variable induction system (disa flap and actuator), as this is a common problem causing the exact cylinder 6 misfire (lean).
Would you be able to check that?
Customer: replied 1 year ago.
I can check that I removed it the flap is not broken if I actually ate the flat valve and hold the vacuum port it holds but if I actually get with a scanner I get no change in rpm whatsoever also I cannot understand or am I misunderstanding you Kennedys of valve cause a cylinder misfire on only one cylinder thank you very much for your help
Customer: replied 1 year ago.
I apologize for that last reply I was using speech to text and I did not proofread it am i understanding you correctly that a dia si valve can cause a misfire on only one cylinder?
Expert:  nabilc replied 1 year ago.
Hello,
I think you got corrected by a spelling software, as i cannot really understand the sentence (ate the valve? kennedys?)
However, the Disa would cause misfire (due to lean condition) on one cylinder (6th), because of air turbulence, causing the air to get mostly on that cylinder.
I would check (even if not broke) using propane or carb cleaner... spraying on the intake hoses etc...
PS: now i got the last message, and yes it can.
Customer: replied 1 year ago.
I install the new DISA valve and I'm still having a misfire on cylinder number 6 sometimes when I shut this thing off I hear a hiss
Expert:  nabilc replied 1 year ago.
Hello again,
The hiss is indicating an air leak... most likely vacuum. Can you pinpoint the location, or try different components? at least make sure you know where the hissing is coming from.
Customer: replied 1 year ago.
I'm about ready to give up now I don't hear it this when I shut it off it sets a 243 code as soon as you take it off idle the DISA valve is new I can actuated with a scan tool but I feel no difference in idle or anything else should the flat be closed at idle or open? I'm not sure where to go next I took compression again 120 psi across if I disconnect the mass air flow sensor I can run the engine and it will not set a code for cylinder number 6 and the injector pulse does not cut out I believe that's normal
Expert:  nabilc replied 1 year ago.
Hello,
did you try checking for vacuum leaks using propane?
Customer: replied 1 year ago.
no luck
Expert:  nabilc replied 1 year ago.
Was the MAF cleaned, replaced etc...?
if not what readings are you getting from the MAF at idle, and as you go revving?
Customer: replied 1 year ago.
I replace the mass air flow sensor with a known good one the numbers on the mass airflow scan tool I would have to check also my short term on both banks is minus 23 percent I'm wondering if a clogged converter could cause this
Expert:  nabilc replied 1 year ago.
Hello again,
get back to me with the checks on mass air flow readings (at idle engine warm, and at 2500 rpm engine warm), along with the short and long fuel trims... as negative 23 percent does indicate a problem (and not a leak), so we proceed as needed.
Regards,
Billy
Customer: replied 1 year ago.
First off thank you for the help and let me know what I owe you the mass air flow sensor a title is 18.10 at 2500 rpm its 55.50 integrator on both banks is staying at 0 and long-term on both is staying at 0 in case I haven't told you a title I have a study 17 to 18 inches of vacuum
Expert:  nabilc replied 1 year ago.
Hello,
All you need t do would be rating this answer (my service).
As for the MAF, how much are you getting at idle, and is the unit in kilograms per hour?
having no fuel trims, at idle and at 2500 rpm (did you check both conditions), would imply that we should have no vacuum leaks.
If the leak issue is confirmed, then the next step would be installing a new software on the DME (engine control module), having checked everything, this would be the next step.
Thank you for your trust! Get back to me if you need more assistance...Thank you in advance for the positive rating...
Regards,
Billy
Customer: replied 1 year ago.
maf readings in kgh ...snap on solus scanner. Updated software for ecm.....? Is this a known issue I am very familiar with calibration updates as I work for General Motors as a tech for 33 years I'm wondering if you could be a little more specific on the reason I don't understand my problem is on one cylinder and basically everything I've checked tells me I have a good engine my the integrity of the wiring and connections is good please don't take me wrong if I had the answer I wouldn't be talking to you I was just wondering if you could be a little more specific whether it is a known issue or something you've seen again thank you for your help
Expert:  nabilc replied 1 year ago.
Hello again,
The reason i'm suggesting to check for any available ECM software updates is exactly because i too think that you have no mechanical problems with the engine, and that the wiring and connectors are good.
The known issues on your engine would be faulty coils (which were swapped or replaced), or air leaks (caused most commonly by the DISA, which was replaced). Those issues cause misfire, the air leak causes cylinder 6 misfire. On bmw systems, we always check for updated software, whenever basic checks don't fix the problem. I'm not saying it's a sure fix, but having everything else checked and operating normally, this is what i would do, at least check if there's an updated software. But did you also check for leaks in the positive crankcase ventilation system, and the valve is good etc..?
Customer: replied 1 year ago.
The only way I know to check for the crankcase leak is to take the oil filler cap off and check for excessive vacuum I have taken it off and I do not believe that it is excessive having said that I could put a man o meter on it just one more thing if I clear all the codes and disconnect the mass air flow sensor wait for it to set the code for the mass air flow and drive it it almost runs good I have checked while it's running I do not lose injector pulse on so number 6 when I reconnect the mass air flow sensor it will idle without setting the misfire code as soon as I take it off idol it will set the 243 code and last night the alternator went out on it lol
Expert:  nabilc replied 1 year ago.
Hello,
Disconnecting the MAF, and still not getting the code, further confirms that the engine is mechanically sound.
Would you be able to swap the MAF only for testing??
Customer: replied 1 year ago.
I have a known good mass airflow from another x5 on there they both do the same thing with a mass air flow disconnected though it will not cancel injector pulse to number 6 but you can still feel slight misfire
Expert:  nabilc replied 1 year ago.

Hello,

This is normal, as when in limp home mode, a slight miss is excpected, and will not trigger a code, thus will not stop the injector pulses.

This also further confirms a vacuum leak issue. However, when taking the compression test, did you have the throttle opened or closed? as at WOT, we should get a more significant result, to eliminate compression problems.

Customer: replied 1 year ago.
The throttle was at wide open I'm confused now do you think it could be a vacuum leak I'm confused now do you think it could be a vacuum leak
Expert:  nabilc replied 1 year ago.

Hello,

From the begining i did suspect a vacuum leak. It's registered in the conversation. It is the most likely cause to such a problem (cylinder 6 misfire due to lean mixture then the DME stops the injector pulses on injector 6).

This is why i started with the DISA check, as this causes a vacuum leak, and it is a very common problem on this model.

I changed diagnostics direction when you assured that no vacuum leaks are present.

But it still is my main concern, since the injectors, coils and plugs were swapped.

Expert:  nabilc replied 1 year ago.

Hello,

I just had the exact same issue today, and the customer got a used ECM, with EWS, and the problem was sorted.

I wanted to reprogram the existing ECM (as it should fix the problem, as per BMW technical service bulletin), but my customer having a used spare, found it cheaper to install, and fix the problem.

Just wondering what happened with your X5...

Regards,

Billy

Customer: replied 1 year ago.
Again thank you for your help after your last post about the vacuum leak I started from scratch my snap on scanner will do a cylinder cancel with the engine running to my surprise cylinder number 4 shows no change cylinder number 6 has the same drop as the rest so when a little further I am plugged cylinder number 4 injector it set a code for cylinder number 5 injector faulty check my wiring against the schematic the injectors are plugged in correctly according to the schematic
Customer: replied 1 year ago.
I took it a step further and I actually crossed cylinder four and five at the injectors I performed the cancelled test again and it was still cylinder 4 that shows no drop
Customer: replied 1 year ago.
But it still set the code four cylinder number 6 code 243
Expert:  nabilc replied 1 year ago.

Hello,

If you are positive that no vacuum leaks are present, then this last message you sent would indicate a software bug within the DME.

Today, i had a similar problem (brought to me from another worskhop), and after checking for leaks (smoke machine), swapping injectors, coils and plugs, and checkinf connectors on the ECM, i concluded that a software update was in order. The other mechanic, having a spare set, did swap the ECM (with EWS), and the problem was gone.

So again, in your case, and given the info, and the last input, i would check for any software updates.