Engine Went Mad... oh not again!!

D

danny_acs

Member
 London
http://www.youtube.com/watch?v=OcGPREEnF24


Left the car overnight outside . I got in and started it and that's what I got. The same happened about half a year ago, but never again so did not get worried to much. Now I am actually worried as warranty runs out in a month...

To describe a bit more: after starting engine normailly, RPM's (throttle pedal position irrelevant, as if it is off), all possible warning lights on. As you see, tried starting several times, and after I stopped the movie clip, the engine actually started fine. The emissions light was on for about 20mins then turned off.

You have no idea how frustrated I am! :headbang: I think this is related to a previousue that you may remember me describing, but the clueless stealer could not fix it 3 times in a row.

Basically, after you drive the car aggressively for 10-15 minutes (high rpms in every gear, 6-7k) and then suddenly switch to normal driving maintaining a constant speed at low rpm (2-3k) its jerks back and forth for about 15 secs as if it's gonna run out of fuel. After that it's fine, but it's really anoying, uncofortable and embarrassing especially if you have a passenger.

I took it to the dealer 3 times in the past 3 months without a result.

1. Murketts: kept the car for a week. Read the computer, found an old error in the DSC module, changed it, said should be ok. I observed the issue again the following week.

2. Park Lane: kept the car for 3 days. Read the computer, changed a cable loom somewhere in the engine bay (did not specify which), said should be ok. I observed the issue again the two weeks later.

3. Park Lane: kept the car for 3 days. Could not observe the issue, returned the car saying it was fine, advised to use premium fuel (duh!?!?!) or change gas station... Of course I asked them if they bothered checking all the sparkplugs (if the electrodes are actually still there), fuel pump, MAF sensor, but got the standard answer that the computer did not show any errors.

To me, it sounds like a faulty fuel pump or MAF sensor, which obviuosly won't display a message on their laptop self diagnostics, but needs thorough inspection involving getting your hands dirty.. What's your thoughts...?
 
Perhaps try a good independent garage and explain in detail what the dealers have done about it and also show the clip?

Or maybe the car is just pissed off that you've put a 2.0i badge on it!
 
Apparently it doesn't have an auto-choke as such, but it does perform the function via the engine management system. This is done using the signal from the engine temp sensors - when it's cold it puts more fuel in.

If the reading from the sensors is fluctuating, the amount of fuel injected will also fluctuate, causing those symptoms when the engine is cold.
 
I had this once about 2 years ago - left it 5mins and it was fine and never did it again.

Reluctant to say exactly the same symptoms but I think it was, I ditched it in a carpark as I was pretty scared it was going to be an Assist job.

Wish I could help, but I never had it again. I don't think it's MAF, nor DSC/ABS sensors..
 
Andy said:
I had this once about 2 years ago - left it 5mins and it was fine and never did it again..
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yep, in 5 mins it was fine.. but mine did it twice in 6 months..

Do you think this and the stuttering is related...?


ga41 said:
....Or maybe the car is just pissed off that you've put a 2.0i badge on it!
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Oh, come on, it loves it being driven as it should! I admit the sports exhaust (which screams similarly to yours from the clip) makes it extra sexy

Now back to issue... any more ideas...?
 
Mine did it too around three or four months ago. I'd been having a "quiet" Sunday drive around a few lanes for about an hour and stopped for a sandwich. Although it was perfect when I parked, upon restarting five minutes later it did exactly as yours did in the clip, with DSC, ABS, and EML illuminated. It persisted with each restart, and on one occasion chucked out some rather disturbing white smoke from the exhausts. I left it for half an hour and it started and ran perfectly. All warning lights had gone out. I checked the engine diagnostics and the only code pertained to "Port Air Relief Circuit Malfunction" (P1417). It's been fine since.
The only other thing I do find with my car is that when driving in steady traffic at a constant engine speed (say at around 2.5-3K rpm), there is a slight hesitation upon attempting to accelerate hard without changing down. This almost always occurs in third gear at around 30-40mph, and instantly clears. I've never had this at revs outside this range.
Not sure if they are related, but I'd be very interested to know what caused this problem in yours.
 
BMWZ4MC said:
there is a slight hesitation upon attempting to accelerate hard without changing down. This almost always occurs in third gear at around 30-40mph, and instantly clears. I've never had this at revs outside this range.
Not sure if they are related, but I'd be very interested to know what caused this problem in yours.
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I have the same, my engine doesn't hesitate, it almost stalls, then shoots forward... I always thought this was engine design flaw...

so about my issue... ECU?
 
if the fault is reported within the warranty period, should they still fix it after the warranty if they fail during warranty, er does that make sense?
 
I get that too in third until it hits certain revs then kicks in. I just assumed it was where the powerband is...
 
danny_acs said:
BMWZ4MC said:
there is a slight hesitation upon attempting to accelerate hard without changing down. This almost always occurs in third gear at around 30-40mph, and instantly clears. I've never had this at revs outside this range.
Not sure if they are related, but I'd be very interested to know what caused this problem in yours.
Click to expand...

I have the same, my engine doesn't hesitate, it almost stalls, then shoots forward... I always thought this was engine design flaw...

so about my issue... ECU?
Click to expand...

No idea what the cause is, but my gut feeling is that it could be a Lambda sensor or mass air flow meter problem as these seem to be common and can disturb the engine management system. Sounds like we need to compare hesitations to see if it is a common fault / characteristic. May be at a track day soon if I can escape work!
 
playalistic said:
I get that too in third until it hits certain revs then kicks in. I just assumed it was where the powerband is...
Click to expand...

It's more than that as I definitely experience hesitancy. If I pootle along in traffic in third, then try to accelerate it stutters before pulling at reduced power. The sensation is the same as when the DSC kicks in, like someone has stolen a couple of hundred horses! However, it won't do it at the same rpm if I've been hoofing it immediately before, slow down, then accelerate again. Similarly, if I'm pootling along, but disengage the clutch and blip the throttle a couple of times, it clears its throat and then will pull strongly immediately when I re-engage the clutch.
No sure I want to line the pockets of a stealer just to confirm what I already know: that I have no fault codes and they have no clues!
 
I’m an ‘old school’ classic mechanical man and the first thing I thought was it sounds like fuel starvation which would have to be eliminated or a timing advance issue. In the ‘old days’ symptoms like these were usually down to the distributor advance system sticking or failing to activate due to the vacuum pipe failing.... Yes I know the Z has moved on but the principle is the same. A quick G search throws up a number of forum sites mentioning similar problems with rise/fall revs and stuttering etc and DSC lights/codes, down to camshaft position sensors. These replicate part of the old distributor timing advance system and will therefore cause similar symptoms. Looking at sites these can fail sometimes on the BMW engines.
Example

http://en.allexperts.com/q/BMW-Repair-805/DSC-problems-onley-its.htm

Worth checking?
 
That looks to be a good answer above.. perhaps only worth persuing if it happens again, as long as it's logged with the dealer.

by the way, the hesitancy described in the posts above is correct, if slightly wierd - it's something to do with the VANOS opening to give full power. It's hard to predict when it will happen, but I'm used to it and the best way around it is just to get much closer to the rev limiter in 2nd before you hit 3rd :driving:

but yes... ambling around town in 3rd, lights change or something and you floor it without changing down, very small amount of power, feels like it's only got about 150bhp, then almost a second later the vanos sorts itself out and you get maximum attack. Don't worry folks :thumbsup:
 
Thanks Ewazix. I googled the OBD code and found other six cylinder BMWs with similar problems. Thankfully mine did this only once as I'm out of warranty.

Andy (and playalistic), very glad to hear that the third gear hesitation is a "characteristic" of the vanos. I'll stop worrying about it now! :D
 
Ewazix said:
I’m an ‘old school’ classic mechanical man and the first thing I thought was it sounds like fuel starvation which would have to be eliminated or a timing advance issue. In the ‘old days’ symptoms like these were usually down to the distributor advance system sticking or failing to activate due to the vacuum pipe failing.... Yes I know the Z has moved on but the principle is the same. A quick G search throws up a number of forum sites mentioning similar problems with rise/fall revs and stuttering etc and DSC lights/codes, down to camshaft position sensors. These replicate part of the old distributor timing advance system and will therefore cause similar symptoms. Looking at sites these can fail sometimes on the BMW engines.
Example

http://en.allexperts.com/q/BMW-Repair-805/DSC-problems-onley-its.htm

Worth checking?
Click to expand...

was reading through your problem and this guy has said exactly what I was thinking. dealers are sort of like doctors I think (no offence to doctors); unless its obvious you need to point them in the right direction and this sounds like it so suggest it to them. hope you get it sorted.
 
doofus4000 said:
was reading through your problem and this guy has said exactly what I was thinking. dealers are sort of like doctors I think (no offence to doctors); unless its obvious you need to point them in the right direction and this sounds like it so suggest it to them. hope you get it sorted.
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Well, I just hope I'm a better doctor than I am a mechanic or my patients are screwed!
 
I supposed it's ok to poke fun at someone now and then. I'm a big girl so I can take it.

To clarify my post, I was suggesting that the method of troubleshooting and the specifics that the people in the thread were following might facilitate the OP through the thought process of someone chasing down a similar symptom. The car's make and model are entirely irrelevant because the laws of physics apply to the internal combustion engines of any make and model in exactly the same manner. If you went to a Subaru or Porsche forum, you'd see a very similar set of threads like the one I posted - nearly identical in the sort of troubleshooting efforts those owners would go through for the same symptoms.

Anyway, I just hope that there might be a bit of information which may cause an 'aha!' moment for the OP and that my post might be able to help. These issues are buggers to get sorted as they say but some of what's in the thread I mentioned would be relatively simple things to try at home and don't require a mechanics level knowledge, just a few minutes time on several of the ideas mentioned.

I had an 06MR and had an extended crank / oscillating & rough idle condition which was never identified. At that time, there was a strong suspicion that fuel quality was at fault but the dealer and BMW couldn't figure it out. I use Shell in my 07MR which is BMW recommended here in the U.S. and with the 07MR, it seems to work quite well. I wasn't using Shell in my 06MR but I stopped going to the conveniently located fuel station on my way home since I had pretty much exclusively used one location back then.

The OP's issue could be related to fuel quality which varies from season to season, region to region (geographically) and by fuel company. You'll start to see more threads on rough idle and hesitation / stumble complains when the weather turns cold. MBTEs can cause a waxy type build-up on the intake valves and the build-up disrupts the A/F mixture from proper stratification prior to the combustion event which can cause a lean condition. There are tons of threads on fuel related issues and sometimes, without the proper test equipment, the person at home is left to his own random troubleshooting effort which can be very frustrating for someone unfamiliar with the way engine systems operate.

I hope the OP gets his problem sorted!

:)
 
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