DD_545i

As I said in the subject, 1 in 20 starts (doesn't seem to matter whether the engine is ice cold or "half hour warm"), I get in the car, turn the key and it sounds like it doesn't quite want to get going. This lasts for half a second, barely long enough to adopt a disappointed facial expression or say "uh oh", and then it springs into life. For the other 19 out of 20 starts, it's strong as an ox. I've tried recording the sound it makes with my phone/camera but naturally I only ever catch the good starts. This has been happening for the last couple of months, which spans the peak of summer (where I suspected it to be heat related) but now continues even though we're only a couple of degrees above freezing.

I'm thinking either battery or sparkplugs. I don't believe (or can't recall) either being changed during the 3 years I've owned this car. It's not standard for plugs to be changed during a small or large service is it?

Spaceroach

i have new plugs and new battery and i have this same issue about 1 in 20 starts as well.

DD_545i

Very interesting. That certainly makes me think I shouldn't rush out and buy either. I'll try and keep track of how often it happens and see if the trend is that it's getting worse.

On mine, the hesitation is very slight. If you didn't know better (i.e. someone else borrowing my car) you might think it's normal and that's just how it sounds when it's starting. It's only because I've heard it start quicker a thousand times that I notice it's not normal.

dawid_w

Hi,

I have similar issue in my 545i (107000 miles). In my case it happens every 5-10 times I start the car.
I suspect bad starter or the non-return valve on the fuel pump.

pcy

I have similar symptoms on my 530i (N52B30). I changed spark plugs, fuel filter, fuel pump, installed new BMW battery. Battery is always above 12.4 Volts with engine not running. I've spent enough time thinking about this issue leading me to think starter is the root cause of the issue. On my car, replacing the starter involves removing intake manifold. That's where I am pausing at the moment. If the symptoms worsen, I will replace the starter.

krn530

My car has similar problems too. I have the 2004 530i. I thought it was the spark plug the whole time. On my iDrive system, it says that my spark plugs needed to be changed. I'll probably get that done and then see if the problem persists.

DD_545i

Caught my hesitant start on video today (after 4 failed attempts to catch it where the start was normal). I threw the various videos together (total 34 seconds). The first 4 starts are different/good starts, so you know what I'm used to hearing. The 5th start is the bad one, which I repeated 3 extra times so you can hear it repeatedly. So 4 (different) good ones, followed by 4 (identical) bad one(s).

How does this compare to the other hesitant starts others have reported in the thread ?

Some might say "is that all you were talking about? that's nothing that, why are you panicking?". I'm not panicking, I'm not terrified, worried or concerned. I'm just wondering and seeing if others share the same minor issue.

http://www.youtube.com/watch?v=hPR83buMC2c

Edit: Just noticed something weird. On the third good start, the rev counter doesn't move at all. Freaky.

Edit2: On the good starts (ignoring freaky #3), the revs pop up to about 1,800rpm on it's little blip of gas. On the hesitant one, it barely reaches 1,500rpm.

pauliehcfr

Mine acts exactly like yours does except when it does the bad start, if I don't hold the key in the start position like a second longer, it sputters and dies. I have tried changing plugs without any change. I was thinking a leaking fuel injector, but I checked fuel pressure and it remained good even after a couple of hours. I just get in turn the key but dont start it, put my seat belt on and then start it. It seems to work ok.

DD_545i

Very interesting. I'll try those two things - (1) wait a fixed number of seconds with all the ignition lights on before turning the key to start (I'll go for 3 seconds initially), and (2) hold the key in the start position until it gives the blip to 1,800.

I think that for the last 10 years at least, I've never given car-starting a second thought. The slightest/shortest of turns of the key to the right and assume that's enough to let the car just get on with it. Prior to that, from the mid 1990s back, you always had to think of starting as something of an art. Using a choke, giving the revs a blip yourself, not flooding it, etc etc.

I assume those who've got the start/stop "button" have exactly the same thing but it being linked to the length of time they hold down the start button, rather than turning the key.

phlfly

it may be absolutely normal,because may be the DME is recording someting during that start so it takes longer so starter disengage late. So the noise is coming from starter.