ditka550

I have a hesitation/miss that happens only on acceleration after slowing down to a coasting speed. It is very evident, but the car has no codes thrown and drives great in every other facet. Its a 2008 550 with the N62 V8 and has 78k miles on it.

I havent done any maintence other than oil changes and a K &N airfilter, cleaning the throttle body and the MAF sensor.

The miss I'm talking about is very evident in the following scenario every morning:

Sitting in a dual turn lane turning left. Cars go in front of me and I accelerate, as we go through the intersection everyone brakes (evidently because they dont own a BMW and understand that a car can actually turn without the brakes applied) but i digress, anyways I lift off the accelerator and then when I go to accelerate again, probably at 15mph or so the car bucks and literally feels like it is starving for fuel. No codes, no CEL and then I give it a little gas and it works its way through the hesitation and I am off.

If i accelerate normally through the gears there is no hesitation either.

I know this isn't a lot to go on, but I'm just wondering if anyone else has has a similiar experience with their N62 and if so what ended up fixing it or even some pointers as to what maybe to inspect. I know the HPFP is not an N62 issue but it sure feels like its starving for fuel.

Thanks!

can-do-kid

I just had the same exact scenario on my 2010 528i with an N52. It didn't throw a code until a week after the symptoms ( same as yours almost exactly) started. It was a misfire in cylinder 4. I have a wifi OBD II reader that I have been capturing data to my iPhone on to see if I could detect something odd. I pulled coil #4 and swapped it with coil #1 to see 2 things. 1. Did the problem move to cylinder 1 ( so I would know it was the coil) or did it stay in cyl 4. Well it must have just been poorly connected or not seated properly because the hesitation and studder went away and the car runs better than I can remember with no symptoms. I have tried hard to replicate problem, but no luck. I learned from this forum about moving the coil so you may try that if you can get a code to throw. Mine did not throw a code for a while so it was frustrating. I hope this helps.

tonyb635

Also similar here but with N54. Mine missed in the mornings for about two minutes and then fianlly through a CE light about one month later. Don't reacall the code, but it was a misfire in number 3. changed plugs and swapped coil 3 & 4 and problem was fixed.

Neal Petro

I had a similar issue before 07 525i N52 it simply would not wanna throw a code finally after a week. It threw a code and replaced a coil along with spark plugs since your in there but any ways I had a buddy where he had the same problem but for about 2 months straight..The solution that worked for him was a different brand of gas on about 4-5 fill ups and was all good I believe he used BP each time-- worth a try I guess

AutohausAZ-Mike

The best way to diagnose the coils is by moving them around to see if the problem continues on the same cylinder or moves. The problem with your situation is that it's intermittent so that will be hard to do until the coil gets worse, which it will. If you do need a coil we carry the original Bosch brand for that car.

Here is a link to the part:
AutohausAZ - Ignition coil


Disclaimer: Make sure to check the year and model of the vehicle before placing the order.

can-do-kid

My problems were gone after swapping coils, but they returned after a few days with a hard misfire on Cyl 4. I finally replaced all coils and plugs and the car runs amazing.

tonyb635

Sounds like you had a bad plug as I did with mine. If I read you post correctly, you origianlly had a misfire in 4 and then after swapping the coils around, all was ok but the misfire returned to #4. I'm assuming you didn't move the plugs arouns at time. If that was the case, most likely your problem was the plugs.

zach1328

It could be anything from spark plugs, coils, fuel injectors, to HPFP and more.

Its tough to diagnose these things without any codes. You're not getting any CEL or SES lights when it stutters/hesitates?

I had similar issue when my n54 HPFP was going bad, but it would also idle rough and was stuttery/jerky from a dead stop too. I doubt the HPFP is the issue - especially on the n62.

Usually when you have a hesitation like such its an excessive amount of fuel. Either the injector is leaking too much gas into the cylinder or your coils/plugs aren't burning as much fuel as they need to. This causes it to hesitate as the engine attempts to burn all that additional fuel that wasn't ignited on the compression stroke.