[rondocap]

On a 2008 335i, I just got new spark plugs done. Car was running fine before, 33k miles, but computer called for it.

Car has PPK and exhibited these symptoms: On a cold start, it had a lot of vibration that was never there before.

Accelerating in 3rd/4th gear caused a strange vibration which seemed to be coming from the back as well.

Now, these never happened before and popped up after the new Spark plugs.

So what exactly can be going on here? Is it something that will go away and needs adaptation, or was something installed incorrectly?

[MikeTerp]

Assuming you had the plugs changed at the dealer, I would head back there ASAP.

[Jeller]

Are you getting any codes?

[MrQuickR1]

The coil sticks pushed down all the way? Connectors at the coil are locked tight? Give each one a good push down and make sure everything is locked.
Usually you would get a code for a misfire but just double check the easy stuff

[rondocap]

No codes, car seems to be running fine for now and it did not happen again. Should I just wait it out and see if it happens?

[fazman]

Originally Posted by rondocap

No codes, car seems to be running fine for now and it did not happen again. Should I just wait it out and see if it happens?

I had the same thing happen to me once I had my spark plugs changed. When I would stop at a red light I would feel the vibration in the steering wheel and then bump the car in neutral and it would be calm... then bump it back into Drive while fully stopped and would get the vibration again.

Since last year it kinda went away on its own and I don't get that issue any more. When I brought it up to my SA, he said the same thing... take it back to whoever did your spark plugs I figure just drive it till I hit about 22.5k miles on those plugs and then just get some new NGK plugs from BMS which run 1 rating colder (Make sure to have them gaped correctly).

[John 070]

I just did my plugs yesterday and wonder what could possibly happen that new plugs cause the motor to not run well? My car runs the same before and after....

[VTECaddict]

Do you have access to INPA? Check for codes and clear the adaptations.

[Dozhdbog]

I just had my sparkplugs changed, and now my car has a long bout of hesitation before pulling under WOT -much longer than I ever experienced before. Also noticed it doesn't feel like it pulls as strong once it does start accelerating. I did some runs using dynolicious to see if what I felt would show up in 0-60 times and clocked around 6.7. My best, prior to having the new sparkplugs put in, was 4.6, and I could consistently get under 5.

Gonna drive it around for a bit longer and see if it goes away on its own, but I've already talked to my SA about it, and told him to be ready for me to come in soon if it doesn't improve.

[iturbo_bmw]

maybe you need to reset your adaptations?

[roadkillrob]

Originally Posted by e92_bmw

maybe you need to reset your adaptations?

+1 probably just adapting to new plugs, either reset adaptations or just give it a week to adapt.