Opening Puma Cases for Dirty Valves
I just got back from the dealer today: my 2007 335i with 60K miles had been missing at wide open throttle, which I can see from this forum is practically guaranteed due to a rather poorly engineered direct injection design for the N54.
The car is a CPO so I still have about 10 months of CPO contract left. The dealer takes the car with the check engine light on and replaces all six injectors. I did not have the preferred "261" model number installed as my car was built in April of 2007. This was all done under warranty. Now that part is outstanding but what was not so good was that I hit the freeway and the car starts missing again.
So I drop it off again and they tell me it has really dirty valves. And they tell me this is a fuel issue: eff you it is a fuel issue. Those valves never see fuel, the car is direct injected. But they tell me that, ordinarily, this will not be covered because of that. Are you kidding me? are you going to sell me a car that becomes undriveable with the check engine light blaring and tell me to eat the cost of the repair? I cannot believe that BMW thinks they can get away with this BS: ultimately, it is a mechanical issue because the car becomes undriveable. I have never used anything but premium fuel in that car. And besides, fuel doesn't wash the intake valves in a direct-injection vehicle. But the service advisor tells me I needed to buy their injector cleaner service more often. I got suckered into that $229 once but the car didn't idle as smoothly afterwards. And even if I had bought it more often, that doesn't have anything to do with scrubbing the valves.
I believe a class acttion lawsuit should be started for all the poor souls out there who are paying to get their valves cleaned. Those valves are dirty because of lousy engineering.
By the way: you better think twice about buying a 2007 335i off warranty: my CPO has paid off with whole new turbos and all new injectors. Think about getting hit with that charge in addition to your car payments. I asked the service provider what the new turbos would have cost me off warranty: he tells me 6K! and that the injectors would have been another 3.5K.