[DaveM235i]

I have to say, the power of people working together in a forum can be awesome.

I've had a cold start issue for 6 months - if you are one of the people you know that it's characterised on a cold startup by a jump to over 2000rpm to a stutter and bounce around 400-500rpm then back and forth, then it settles.

To cut a long story short, it's been into BMW several times, run fuel cleaner, tested, reprogrammed to no avail.

I reached out to a forum member also in Australia who had the same issue and luckily had it resolved (i know there are quite a few US, Canadian and Euro guys that have also had this issue). I forwarded this onto my Service Manager who went to BMW Australia and they decided to try it on my car and it is now resolved.

The issue was the injectors on both of our vehicles. He had another item replaced as well but this is the common replacement carried out between our cars.

I wanted to share this as an option if it has not been considered for your vehicle. Hopefully, this delivers a positive result for you also.

[Knightelf]

Hey Dave. I have been having this issue for about a month. The issue started when I changed my intake filter (I have an aftermarket intake) so I had thought it was because of that, but maybe it was just a coincidence. On cold starts it stutters like yours did, on cold days it may even turn off after the stutter, but typically it jumps back over 2k and then settles down. I haven't taken it into BMW yet, but if it's a known issue maybe I should.

[DaveM235i]

Originally Posted by Knightelf

Hey Dave. I have been having this issue for about a month. The issue started when I changed my intake filter (I have an aftermarket intake) so I had thought it was because of that, but maybe it was just a coincidence. On cold starts it stutters like yours did, on cold days it may even turn off after the stutter, but typically it jumps back over 2k and then settles down. I haven't taken it into BMW yet, but if it's a known issue maybe I should.

If you still have the old intake, swap it back and try it for a few days. it's unlikely bmw will touch it with the aftermarket intake. they troubleshoot stock under warranty. i was even advised by my service manager to switch back my drop in panel filter to the standard cotton. it sounds silly but he was only helping me out to make sure it doesn't get rejected at the higher level. from the 6 months that it has been in and out, they had no idea (on their records) of the issue or the fix. this is why i posted this, just in case this is your scenario and it sounds like it is. i hope you get it sorted

[aozer]

what exactly did you forward to your service manager? i have the same issue and have yet to take it in, but would prefer to avoid the process of going in for multiple fix attempts.

[DaveM235i]

Originally Posted by aozer

what exactly did you forward to your service manager? i have the same issue and have yet to take it in, but would prefer to avoid the process of going in for multiple fix attempts.

Long story is that I had to go through a 6 month process of elimination. We agreed it was fuel related and I had to drop to 95Ron from 98Ron fuel, change suppliers, have it reprogrammed several times. I sent them a fix from another member that had resolved the issue through his BMW service centre. They had swapped out his Valvetronic motor as advised by BMW under the PUMA. They had to replace a few injectors as part of that process too. Using this information, BMW Australia advised to swap out the injectors first. They did this and the car has been perfect on start-up. Even in the example I sent to them, it could have been the injectors only but they went to the Valvetronic motor as the main issue on that occasion.

The common fix on both cars though is the injectors and we have both been fine. Forward this on.

My thoughts are that they will run tests on your car first as they have to run the process first instead of outlaying for injectors - try to push this through but I reckon they will muck you around a bit first and then at last resort try this option.

Good luck

[Taunto]

This is an on going issue with the N55 engine. We see more of these issues here in Canada in the winter months more often.
One of the problems we get is the DME wont register it enough to even set a fault, which makes running test plans with the BMW Scan Tool ISTA/D, not work very well as the test plan cant seem to pick it up.

Seems like every vehicle it ends up being different issues, Some with Aftermarket intakes, Some with MAF sensor problems, Injectors, Coils/Spark Plugs, Programming, Fuel quality, Even Eccentric shaft, Cylinder heads, ect.

Most of these issues we get each one ends up with a different solution.

Interested to see what you guys find to always resolve these issues. First time ive heard of these issues happening in warmer climates such as Australia and Texas.

[DaveM235i]

Originally Posted by Taunto

This is an on going issue with the N55 engine. We see more of these issues here in Canada in the winter months more often.
One of the problems we get is the DME wont register it enough to even set a fault, which makes running test plans with the BMW Scan Tool ISTA/D, not work very well as the test plan cant seem to pick it up.

Seems like every vehicle it ends up being different issues, Some with Aftermarket intakes, Some with MAF sensor problems, Injectors, Coils/Spark Plugs, Programming, Fuel quality, Even Eccentric shaft, Cylinder heads, ect.

Most of these issues we get each one ends up with a different solution.

Interested to see what you guys find to always resolve these issues. First time ive heard of these issues happening in warmer climates such as Australia and Texas.

Thanks for the feedback. That is correct, no faults were logged which made it frustrating and then just a long process of elimination.

[DanielGr]

How many km's on your cars before it started doing this?

[DaveM235i]

Originally Posted by DanielGr

How many km's on your cars before it started doing this?

Not sure to be honest. Overall it's done 18,000 km's. I would say about 12000 ish at the first sign of this - it was 6months ago when it first started. Middle of Summer in January so it's not just a cold climate / seasonal issue either.

[DanielGr]

Originally Posted by DaveM235i

Not sure to be honest. Overall it's done 18,000 km's. I would say about 12000 ish at the first sign of this - it was 6months ago when it first started. Middle of Summer in January so it's not just a cold climate / seasonal issue either.

Interesting. Mine only does the few seconds of rough idle/judder on some starts (not necessarily cold), but it's only at 10500km atm. Will take a mental note about this thread

[DaveM235i]

Originally Posted by DanielGr

Interesting. Mine only does the few seconds of rough idle/judder on some starts (not necessarily cold), but it's only at 10500km atm. Will take a mental note about this thread

Hey Daniel, this is how mine started. It started out sporadically, then became every 2 or 3 starts then went to every single start. Hopefully this doesn't occur with yours and it gets straightened out. If it does become more regular, get it checked out as it may follow the path that mine took.

[koston]

Great post, Dave. I'll definitely keep this in kind, as my car is close to 12k.

[Knightelf]

My issue started after I changed the intake, so I don't think it is the injectors. I have read a number of posts where people have had issues with aftermarket intakes. Cold weather makes it worse for me... may have to go back to the old intake

[x3user45]

I just experience a similar issue for the first time after having the Dinan cold air intake installed. It only happens on cold start when parked overnight in my garage, what are the dangers of this if any?

Its only happened twice, in past 2 weeks since I had the intake installed, I will contact my dealer who did the Dinan install if it continues.