[CHhuBby619]

Hey, I own a 2010 BMW 328i xDrive with a little over 110k miles on it. I was running the lowest octane fuel I could when I got the car at 84k miles. Recently I decided to start running higher octane fuel or Premium fuel. Since I started using premium, the car will shake and almost misfire from a cold start. It will do this for about 10 seconds and will run perfectly fine afterward. Just wondering if there’s a reason for this?

This weekend I’ll be doing some maintenance work, spark plugs and coils to see if those are the culprit. Just wondering if I should look into anything else while I’m in there.

Thanks

[gavinm002]

Is it more of a shuddering or a rocking? Might sound weird but I've heard before that a couple of seconds of the engine running rough and rocking the car a bit right after starting is "a three-series thing"

My '12 e91 does it every now and then and so does my buddy's F30 340i.

I've always run 93 (91 isn't common in my state) and have almost all fresh plugs and coils.

Interested to see if anyone else has heard this or if it is common as I've always perceived it to be.

[CHhuBby619]

It’s more of a shudder. The rpm’s seem to dance around the 1k mark when it does it.

Good to hear that it might just be a 3 series thing.

Thanks!

[Brian86]

Higher octane fuel is more difficult to ignite, so it could be accentuating fouled plugs or weak coils that otherwise don't have issues with more volatile fuel.

Try a tank of 87, see what happens.

It's probably not really problem.

The golden era BMWs, late '80s to early '00s often ran like crap when cold, particularly when the weather was cold.

the mid '00s cars seem to have mostly solved that, seemingly by dumping gobsmacking quantities of fuel down their throats until they warm up a little.

[Cpet]

My car also runs a bit rough for the first 15-20 seconds on cold starts. Not every time, but enough to bug me. I only run shell premium fuel. My coils and plugs have been changed within the past 10k miles, and I recently cleaned the VANOS solenoids.

[CHhuBby619]

Updated: Just swapped out the coils and spark plugs. They old one looked good, they only had about 10k miles on them to begin with. Still kind of jumpy at the start but idled perfectly fine after a few seconds.

I did notice that there is a leak coming from the Valvetronic motor gasket. Could me putting in premium fuel be exposing that fault?

I am getting that ordered here soon to swap out.

Also, I don’t think my VANOS solenoids have been cleaned or changed. Should I get those serviced soon?

[lookalikehuuh]

Originally Posted by CHhuBby619

Updated: Just swapped out the coils and spark plugs. They old one looked good, they only had about 10k miles on them to begin with. Still kind of jumpy at the start but idled perfectly fine after a few seconds.

I did notice that there is a leak coming from the Valvetronic motor gasket. Could me putting in premium fuel be exposing that fault?

I am getting that ordered here soon to swap out.

Also, I don’t think my VANOS solenoids have been cleaned or changed. Should I get those serviced soon?

No premium fuel would not cause that at all, crappy german gasket do, get used to oil leaks needing to be fixed on the regular.

Yes you should clean your VANOS which can make a huge difference in the smoothness of the engine.

[NZE90]

Check your DISA flaps as well. I had rough idle on start up when mine was stuck open.

[mecheng77]

Not uncommon, if the maint is up to date don’t worry about it.