Idling like a bag of spanners after long rest

[sp3ctre]

After I have left my car for a while (couple of days), when I start it up in the morning it struggles to get going, then it idles like a bag of spanners. If I leave it for a minute, turn it off and then try again it is fine. One time I tried to drive off when it was rattling and the check engine light came on. I stopped immediately, turned off and then on and it was fine again, same as if I just wait a bit and then re-try)

I first noticed this after coming back from a few weeks holiday, but now it does it every monday morning (if I haven't used it over the weekend).

I wondered if it was the battery but there is no yellow mark in the window, rather it is black (insufficiently charged). Could this mean the battery is on the way out or could it mean something else? I an happy (well, not happy, but you know what I mean) to go buy a new battery, but I don't want to spend a load of cash on a new batter if it is not the problem.

I know nothing about these things, but I would have thought that if it was the battery the engine would either start or not, I was not expecting it to kinda-start.

On that note... over to the experts...

 

[Greeno]

sounds similar to what srhutch was describing with fluid drain off here:

http://www.z4-forum.com/forum/viewtopic.php?f=3&t=10937

 

[Taz]

sounds similar to what srhutch was describing with fluid drain off here:

http://www.z4-forum.com/forum/viewtopic.php?f=3&t=10937

+1

 

[srhutch]

No the boss has a M54 no such issues.

 

[Taz]

perhaps it just needs oil then :wink:

 

[sp3ctre]

Thanks guys, yeah I have the 3.0SE from 2004 (M54). It does sound like a similar issue except I can guarantee when I turn it off and back on it will be ok again. Oil level is definitely ok. What do you guys think about the battery idea?

 

[adam81]

I know you say the oil level is ok, when was it last changed or topped up?

I doubt this is a battery issue specially if it sounds like a bag of spanners :|

 

[gannet]

coil pack ???

 

[sp3ctre]

I did think coil pack but would that fix itself after a restart, and would it only happen after a few days off?

 

[gannet]

I did think coil pack but would that fix itself after a restart, and would it only happen after a few days off?

no idea :?

I've only encountered rough running after a longish rest when that has followed starting the car and only moving it a short distance - such as moving it off the drive. attributed this to rich petrol mixture not all burned previously etc ?

 

[sp3ctre]

I know you say the oil level is ok, when was it last changed or topped up?

I topped up a few weeks ago when the yellow oil light came on... double checked and it still looks fine.

 

[sp3ctre]

I did think coil pack but would that fix itself after a restart, and would it only happen after a few days off?

no idea :?

I've only encountered rough running after a longish rest when that has followed starting the car and only moving it a short distance - such as moving it off the drive. attributed this to rich petrol mixture not all burned previously etc ?

I think that was the case in this instance, although it seemed more than rough running, more like shaking.... bizarre though that if I leave it for a minute, switch off and back on it is like there has never been a problem at all.

Thinking back, when I came back off holidays it was like it really struggled to start.... was the same symptoms as this but worse. Still, waited a min, off then on and it was fine... I am stumped!

 

[EdButler]

This is one of those things where it could literally be anything im afraid! Firstly, try to see if there are any codes stored in the ECU. A video of it running may also help diagnose if its on 5 or less cylinders. How many miles has the car done?

Battery SHOULDNT be a problem. If it has enough juice to crank the engine over, it will have enough to provide the initial spark. Then the alternator will take over.

My initial feelings about this would be worn out VANOS seals or a vacuum leak somewhere. Also the Crank Case Ventilation system can cause lumpy idles, so check for any signs of oil residue around the valve cover, oil filter housing and dipstick tube bottom.

Does it correct itself if you DONT turn it off/on again once warm? Like if you give its a few revs? If you're capable, id try whipping out the coils/plugs after its been running rough for a minute or so, to see if there are any signs of specific cylinders being problematic

An easy thing to try tomorrow morning would be to start the car with the MAF disconnected also (1" wide plug on the top of the pipe just behind the airbox).

Sorry about the the torrent of responses, im afraid its just the nature of the problem!

 

[sp3ctre]

Thanks Ed, I will check out the things you say and drop a video online as soon as I can get it to reproduce the symptoms... A single night is not long enough to leave it, it needs to go a whole weekend usually before it does this. Might see if I can borrow the wife's car and leave mine on the driveway for a day or two.

Thanks... was hoping to keep this one for a while, so hope it is nothing too serious

 

[EdButler]

Don't worry it doesn't sound major, just annoying to find! I think the reason why it starts running fine after a warm restart is due to the lambdas being warm enough to kick in after a reset and adjust the mixture accordingly. If you do manage to get the codes read (maybe worth asking around people in your area if not, i'm in Sheffield if you're ever down here!), i'm expecting a cylinder rich/lean/misfire code.

So save you making a Video for yourself, if it sounds like any already on youtube that could help
http://www.youtube.com/results?search_query=bmw+rough+idle&aq=f

 

[sp3ctre]

mmm, hard to tell really, it didnt sound like the ones I saw from the youtube list, but then again it may well sound different when recorded. My concern is I am going on holiday soon, and considering it had big trouble starting when I got back last time I am a bit worried what it will do this time. Luckily we can take the wife's car to the airport, so I don't need to worry about getting stuck in the long-stay.

 

[sp3ctre]

Here you go... did it again this morning, although not quite as bad as normal because it was moved over the weekend:
[youtube]RkQh-3q0-Go[/youtube]

 

[pvr]

Why is your battery light coming on?

 

[sp3ctre]

That's the coolant light, isn't it? It comes on every morning and then goes off pretty soon. Coolant level looks ok though. It's only started with that light since I topped up the oil...

 

[pvr]

That does not look right. That light should not come on after a bit. Almost sounds like the water pump is doing something not right.