Cold start RPM drop and vibration

[eggyacid]

So I had this "issue" for over a year but dealer could never find the issue. It doesn't throw any code and they never keep the car long enough for it to reproduce.

I only drove this car on weekends and sometimes I wouldn't drive it in few weeks. During cold start, the RPM would drop below 1000 and car will vibrate to almost stall but once I drove the car it's all good for at least a week.

Had the car in last time under CPO warranty and paid $149 for diagnostic yet came back as everything normal because no code.

I posted a small video on my Dropbox hope this will explains it better.

https://www.dropbox.com/s/7h3m7yzhqh..._0490.MOV?dl=0

[turboawd]

Perhaps a misfire. Ever change your sparkplugs?

[Silververtu]

Did you show the service mgr the video?

[eggyacid]

Originally Posted by turboawd

Perhaps a misfire. Ever change your sparkplugs?

That's my next step is the change out all the plugs. I just hit 60k miles

[eggyacid]

Originally Posted by Silververtu

Did you show the service mgr the video?

Yes I did, he said that doesn't tell him much and he still need it to generate a code

[Rotzy]

Originally Posted by eggyacid

Yes I did, he said that doesn't tell him much and he still need it to generate a code

Sounds like a lazy service manager. As others have suggested, I would start with plugs.

[Florida-X3]

Ah yes, the old "it's not broken unless it throws a code". We had a Sterling (yeah, I'm the guy that bought one) and we had some lights out on the dash. So I took it too the dealer and they said the "machine" didn't say any lights were out. It was in the middle of the day and mind you, this was not our first issue with this car. In frustration I grabbed one of those large rugs that a service comes and swaps out with clean ones one a week or so and through it over the top of the car to cover the windows. I turned the lights on and then told the service manager to get inside and tell me there are no lights out. Needless to say he felt foolish. I told him they should trust their customers more as we live with the car every day and did he really think I wanted to take time away from work and go through this hassle?

[DuSh]

Originally Posted by Florida-X5

Ah yes, the old "it's not broken unless it throws a code". We had a Sterling (yeah, I'm the guy that bought one) and we had some lights out on the dash. So I took it too the dealer and they said the "machine" didn't say any lights were out. It was in the middle of the day and mind you, this was not our first issue with this car. In frustration I grabbed one of those large rugs that a service comes and swaps out with clean ones one a week or so and through it over the top of the car to cover the windows. I turned the lights on and then told the service manager to get inside and tell me there are no lights out. Needless to say he felt foolish. I told him they should trust their customers more as we live with the car every day and did he really think I wanted to take time away from work and go through this hassle?

I still don't understand, they should be trying their best to find an issue with the car, as they get paid for it by BMW. If I'm not mistaken servicing is their major profit nowadays, not selling cars. Why they still behave like that is a mystery to me.

[M302_imola]

Sometimes on cold starts I get an initial rev in RPM's followed by a quick drop like you described. Car doesn't really vibrate but almost sounds like it's going to turn off. It has never turned off and happens once in a blue moon so I don't pay much attention to it. That being said, I do need to replace the spark plugs as I'm just over 60K miles.