WBANW53508CT51832I'd swear it started happening right after I got an oil change at Jiffy Lube. They over filled it, but only by about 8oz...those things are SUPER touchy (oil level meter was only in the yellow). I had my indy drain a little.Anyway, not to throw you off the trail... but I do remember that.That said, around last November I changed the plugs. (At around 95k miles) OEM Bosch plugs...same as I took out. Car has no mods at all.
It had been severely bogging down with heavy throttle in high gear under load...like a car would with bad spark knock, but I guess the sensors make the computer dial back the timing to avoid the knock. There was a MARKED improvement in the low end torque. Before the plugs, in 4th gear at 40 miles an hour, i put my foot 3/4 throttle and it would just lay there...the engine
would even dive a little. Changed the plugs and it was a beast. It was also getting into winter.
Now the symptom is different. It hesitates...occasionally lurches a couple times, and then takes off. Even from a dead stop, if I hammer it (regardless of DTC setting) the engine dives a few hundred rpm, and then takes off. Used to be that it would just start pulling solidly, and then really light up around 3500rpm...the BMW way.Main thing is, when it's 50 degrees outside, it's not a problem. When it's 90 degrees outside, it happens really badly.Seems like an intake thing to me. Like hot air moving too slow. I checked the air filter, the MAF, all the intake hoses. All good. No other codes besides the 2B70 on the work order....but he said there were a couple other "major" codes that weren't related. Indy looked it over really carefully, too. I've used him for years. He has an AutoLogic and is generally pretty good with diagnosis. He said he couldn't feel it when he drove it, too. But he only drives it about once a year, and then just gingerly around town at 40mph.Let me know if that helps.I know the car really well, and I'm certain something's up. But I can't be sure what.