e39 540i stalling at low revs...hunts while idling any ideas?

[wobbly47 0]

Had to happen really didnt it as ive been going around since ive bought the car boring people with how damn reliable and awesome these cars are!!! She seems to have developed a fault, when i say developed i mean its done it about 3 or 4 times so far, but would like to solve it before it develops.

The car has stalled from idle a coulple of times and before it does it it has "hunted" revs rise fall a bit on the verge of stalling before it finally does.......also when you try to restart it it hasnt wanted to start instantly like it normally does and has taken a but of throttle and a few goes, car seems to be firing on all 8 pots even when hunting......did worry me the day this happened and it also revved up a bit on its own when leaving a carpark......almost like the AC had been put on. hasnt played up today tho and has been faultless,

Any ideas?

cheers Deano

[entscheidend 0]

I would start with getting it scanned for faults. How may miles?

Whens the last time the spark plugs / air filter was changed?

I would start with the:

1. MAF sensor

2. O2 sensors

3. Intake

[rjac001 0]

it sound silly but check and make sure all the leads are securely attached to the plugs and getting a good connection ie not wet or dirty or anything... chances are its an ignition problem so after that I would check Dizzy cap and rotor arm, could have a crack and now with the colder wetter weather very easy for moisture to get in and that will cause the problems your having

[*Glenn* 854]

Once again....this is a M60/M62 motor...not an M20 or M40

[Greg111 13]

it sound silly but check and make sure all the leads are securely attached to the plugs and getting a good connection ie not wet or dirty or anything... chances are its an ignition problem so after that I would check Dizzy cap and rotor arm, could have a crack and now with the colder wetter weather very easy for moisture to get in and that will cause the problems your having

Haha that just cracks me up!

[wobbly47 0]

cars a 1999 model its standard other than a cotton filter element which is clean, mileage 47k full history......have to agree think it might be a sensor or somethig along those lines, will take it in to be scanned this week.

re plugs what are the best to put in?

cheers Deano

[*Glenn* 854]

cars a 1999 model its standard other than a cotton filter element which is clean, mileage 47k full history......have to agree think it might be a sensor or somethig along those lines, will take it in to be scanned this week.

re plugs what are the best to put in?

cheers Deano

Either Bosch YTTRIUM FR 7 LDC+ or FGR 7 DQE+

[10hove 0]

Either Bosch YTTRIUM FR 7 LDC+ or FGR 7 DQE+

over the last 12 months weve had over a dozen 5 series and 7 series with these sysmptoms in nearly every case it has been the airflow meter.

after replacement all clients report both better performance and economy.

regards

alex

carspot

[*Glenn* 854]

will take it in to be scanned this week.

cheers Deano

Get it scanned first and get them to check live data readings while driving the car. Air mass Kg readings should be around 20kg @ idle and under full load it should increase rapidly up to 600-700kg with a V8 engine

If there are oxygen sensor limit fault codes, they will be they result of another problem ie: air leaks from manifold or crankcase ventilator valve

[kerrynzl 3]

I would check Dizzy cap and rotor arm, could have a crack and now with the colder wetter weather very easy for moisture to get in and that will cause the problems your having

Hahaha!

I took your advice and checked the Dizzy Cap and Rotor Arm on my E36 [ the damm thing has been stolen!!! ]

No wonder my Beemer is slower than my Big Block Corvette

Maybe I should look at fitting a "mallory twin point" and a "Holley" to my M50 engine [ plus some fuzzy dice on the mirror ]

[elmarco 56]

Go the fuzzy dice!!

[wobbly47 0]

cheers guys will let the guys know your findings on other cars friday.......much appreciated, hey alex faster after the faults been sorted BLOODY HELL, its quick enough already, and averages about 9 lts per 100km (with the wife driving)

I spent days looking for a dizzy cap even took the motor out still havent come across it yet, lol

cheers Deano

[wobbly47 0]

need some advice from you tech guys, took the car in today for the service and rough idling, guess what somehow they have wiped the brain on my car and now they cant communicate with it, nothing works wont even start.......the service manager says it happened when they were fault reading and resetting the values and removing the tail light bulb warning info id asked them to do (after new lights), the service manager is now saying it might be the one and the same fault that was causing the idle problems that caused the ECM or whatever they call it to crap out........now to me being a distrustful bastard it seems very unlikely that my car would decided to wipe its own memory the day its plugged in to the BMW software......they told me they were doing a firmware software upgrade at the time.

Now the vehicle is as luck would have it covered by warranty......but as i said to the bmw guys who seem to be trying to go down the road of "it just crapped out when we had it....bad luck" I need to know for definate that the idling problem and the brain crapping out are one and the same, if so, no problem sweet, but if they are not why should i be liable for a $400 excess on something they could have caused......can i ask them for proof that the fault was unrelated to them pluging in? Or would it be my job to prove otherwise??

My other concern was that if i end up paying the excess and getting a new brain put in and the problem is still there with the idling i may have to pay out another $400 excess to put that right, i told the service manager this and that in my opinion we need a diagnosis for why it happened, not just put a new black box in......

Also in my personal experience u cant corrupt a computer system without doing something to it........would it be the same with this?

Anyway they say they will know more on monday........hopefully i will too, and if it turns out to be totally innocent and pure luck that it crapped out on its own i'll take it on the chin, but id like to be informed as to whats going on which no one seemed to know, which always gets the alarm bells ringing.

Any advice greatly appreciated guys

[jochen 4]

All depends what tools they used.

Was it a BMW dealer with BMW diagnostic tools?

Mostly fail-safe.

But - databus corruption can occur, and low-voltage can cause problems.

A good garage will know that battery voltage is critical when writing / reprogramming, and will connect a battery charger.

And databus corruption can occur through eg worn ign switch contacts.

Very hard to diagnose your problem further....

Oh: and if it is the M62 (and not M62TU) engine, give the Idle Control Valve a clean with carb cleaner - I bet it'll be grubby and sticky, this also causes idle problems. Mine made a big difference, and was very easy to remove and clean.

Edited April 17, 2009 by jochen

[jochen 4]

Had to happen really didnt it as ive been going around since ive bought the car boring people with how damn reliable and awesome these cars are!!! She seems to have developed a fault, when i say developed i mean its done it about 3 or 4 times so far, but would like to solve it before it develops.

The car has stalled from idle a coulple of times and before it does it it has "hunted" revs rise fall a bit on the verge of stalling before it finally does.......also when you try to restart it it hasnt wanted to start instantly like it normally does and has taken a but of throttle and a few goes, car seems to be firing on all 8 pots even when hunting......did worry me the day this happened and it also revved up a bit on its own when leaving a carpark......almost like the AC had been put on. hasnt played up today tho and has been faultless,

When the M62 engine idle speed drops under load eg: when shifting P to D, or when switching on AC, then the idle control valve is sticky because it is dirty. If the engine sometimes stalls under these situations then it is highly likely the ICV is the culprit.

Easy fix: remove and clean with carb cleaner and refit.

Very accessible, very easy Sat morning job.

PS: above applies to M62 only (pre Sept 1998), not to the M62TU (Sept-1998 onwards)

[wobbly47 0]

cheers Jochen,

the cars a 99 model with 45k full history, id like to think anything being worn out would be unlikely??

the guys that did the work are a bmw service agent with the correct diagnostic gear, now its all corrupted what next....how do you fix it, and is there anyway of proving for sure what caused it? or do i have to take it on the chin and pay to put it right?

now i have to drive my van at the weekend.......thats depressing

cheers guys

[*Glenn* 854]

The engine fault codes are stored in the DME and diagnosis for that fault should have been done there... what was the fault code in the DME for your stalling problem ??.. We download all fault codes onto a PDF file before carrying out any repairs... mainly to cover ourselves in the event of something going wrong or a similar fault occuring further down the line

Turning your rear light warning off should have been done in the LCM or Central body control unit

I cant comment any further because I dont know all the actual facts. You may actually now have 2 problems, if so, you will have to pay 2 excesses. As Jochen said, it may have crashed when recoding... this can happen and most dealers get you to sign a disclaimant now if recoding is necessary... especially on the later model cars ie: E65's & E90's

[wobbly47 0]

cheers Glenn, the fault happened when they were updating the software in the DME, thats what i was told, the mechanic said it only had one fault code and that was for the thermostat which was fine.......so who's liable for the repair if i didnt sign a disclaimer? And what do they do to repair the DME and is it expensive?

like i said before i have no issues paying for a repair if it was going to crap out anyway, and ive used these guys for years with my mitzi and they have always been exellent to deal with, just dont want to pay for someone elses mistake (if thats what it is) thats all.

cheers Deano

[kiwijoe79 0]

cheers Glenn, the fault happened when they were updating the software in the DME, thats what i was told, the mechanic said it only had one fault code and that was for the thermostat which was fine.......so who's liable for the repair if i didnt sign a disclaimer? And what do they do to repair the DME and is it expensive?

like i said before i have no issues paying for a repair if it was going to crap out anyway, and ive used these guys for years with my mitzi and they have always been exellent to deal with, just dont want to pay for someone elses mistake (if thats what it is) thats all.

cheers Deano

Did you not say they where BMW dealers, ive never seens a bmw dealer work on mitsi, I have had issues where the map cooling thermostat has caused stalling at idle due to shorting on the heating element, if the fault comes back with the new DME then i would get this replaced, the engine has map cooling to run hotter under lean cruise, if map cooling is not working then it will always run hotter than recommended for particular driving, or the fault could be logged because car is running too cold and cannot regulate temp correctly. This will pay for itself based on the fuel consumption will be gained, as for the surging, i would be very surprised if there was not faults relating to mixtures or throttle problems.

If it is not a BMW specialist it is possible there test equipment is not picking up the correct fault memory

[darkwolf 0]

From my work with computers in the past. Flashing is one of those things that should only be done if necessary as it makes the chip completely unusable in the event of failure part way through.

I would say (but unfortunately I don't know how you'd prove it) that the flashing of the chip caused the failure.

Either way you look at it they're cornered. If the idle problem is there after a new chip, then they haven't fixed the problem which is what you took it to them to fix before the chip got fired. If it goes away, they were right but you're still down $400, which sucks. If the idle problem is still there and they try to make you claim again, it means the chip was fine before they broke it. I'm pretty certain your warranty company will be savvy on the goings on anyway.

[wobbly47 0]

cheers kiwijoe........what you say about the stat is interesting, matches up with the ifault code and maybe the idle problems from what you say, we will see (in 4 weeks tho due to the new DME having to come from germany!!!

$2000 jus tfor the blackbox (Thank god for warranty's)

RE them being BMW dealers......they are not as we dont have one in Whangarei anymore.......i was told they are the service agents for BMW and have a specialist mechanic who only works on them, I had no reason to doubt this as they had shed loads of beemers being worked on everytime i went there.

Darkwolf my argument with them is exactly what you say.........ive already decided they can wait for any excess to be paid until we've driven it for a while to make sure the idle fault is sorted...........i also wonder whether i should let the warranty company know whats been going on?? I dont want to be stuck in the middle still with an idle fault and another excess if it turns into a blame game.

I'll keep you posted

ps i hate driving my van.........ive been spoilt

[darkwolf 0]

Definately keep the warranty co in the loop. If for no other reason than to know where you stand with everything. You don't want to end up paying two warranty excesses. I've dealt with my warranty people 3 times thus far. I'm with AA. They've been pretty good each time. Only had to pay two excesses too.

[kiwijoe79 0]

Definately keep the warranty co in the loop. If for no other reason than to know where you stand with everything. You don't want to end up paying two warranty excesses. I've dealt with my warranty people 3 times thus far. I'm with AA. They've been pretty good each time. Only had to pay two excesses too.

Just note that warranty companies will not covere items failled whilst doing software updates, they do not pay for coding or programming, and this will be in your policy book, if they are told how it crashed you could end up paying the whole bill

[wobbly47 0]

Just note that warranty companies will not covere items failled whilst doing software updates, they do not pay for coding or programming, and this will be in your policy book, if they are told how it crashed you could end up paying the whole bill

cheers mate.........ill check my policy.

[entscheidend 0]

cheers mate.........ill check my policy.

Deano - go to Archibald Mitsubishi and ask for a guy called Anthony (better known as AJ), hes a short stocky Moari chap. Anthony used to work at Northland Prestige and Team Mcmillan prior to that. There is a tech there called Nick - hes German. Hes good on BMWs too.

Failing that there is always Betta Motor Works on Water Street.

Anthony is your best bet when it comes to the DME