Hey everyone. Just joined the forum today, glad to be a new owner of a E92 335i
First, a little background... after a couple months of deliberation I bought a 2007 certified pre-owned 335i 6MT in mid July with 26,500 miles. Four miles (yes, four miles) away from the dealer in my new car, I experienced the dreaded HPFP failure. Upsetting yes, but good to get the pump replacement out of the way before I needed the car to get to work or something like that.
Since then, the car has been fantastic. I love every minute behind the wheel. However, I have begun to experience this very strange jerking feeling under hard acceleration. It only seems to happen in higher gears at lower speeds (low-ish RPM). For example, on the highway around 30-40mph in 4th gear mash the throttle and as the RPMs rise past 3-4k there are tiny hiccups in the power delivery that cause a jerking sensation. It doesn't always at the same RPM, and is in no way consistant. I know that it is not a traction problem, because it only really happens at higher speeds.
I took the car to the dealer recently for the 30,000 mile service and mentioned it to the service guy. He said they would drive the car and attempt to reproduce the problem. When I returned the next day to pick up the car, he said they couldn't find the issue. I was happy at first, but quickly crushed to feel the exact same jerking upon leaving the dealership.
I'm probably going to return to the dealer sometime soon and go out for a ride with the mechanic to show him the issue. My completely uneducated guess would be that it something to do with the injectors or the spark plugs maybe? It doesn't feel like a transmission issue.. Any ideas of what the problem is or what I should do would be much appreciated. Thanks!