I have a 2007 530xiT with 117,000km. Recently, I have noticed some issues when I slow down to 20km/h and re-accelerate. There is a slight hesitation when re-accelerating, I suspect a misfire but there is no CEL.


Also around 80km/h (constant speed), while cruising on the highway, there is a feeling the car is pulling/pushing.


Not sure if it is engine related or transmission because on 2 occasions while re-accelerating from 60km/h to higher speed, I felt a jolt.


I scanned the car, no error codes.


Do I just wait and monitor???

 

You meed to give more info. How old are your coils and plugs?

 

FWIW, I had micro cracks on a set of coils on another car which would provide inconsistent hesitation and stumbles here and there but not be enough to trigger the CEL.

The micro cracks did act up though more when it was humid or raining. One way you can check beside visually looking at them under a magnifying glass is to mist some water on top of them and see if the car runs rough in any way.

 

Coils are still originals, car is from 2007. Plugs are due soon. Car does not have much mileage (117,000 km)

 

Will keep an eye out, been dry this past few weeks. I did notice the issue is more prominent when the AC is running.

 

maybe because there is more load on the engine with the A/C running. new coils and new plugs wouldn't be such a bad idea anyways.

 

Finally got the CEL yesterday morning. Misfire on cylinder 6, replacing coil and all spark plugs.

 

When was the last Walnut blast you did, and what is your mileage now?

 

I have 118,000km and contemplated a walnut blast but I am not convinced it is necessary on a 2007 normally aspirated engine. Walnut treatments are more relevant on turbo engine cars.