Frustrating 135i bucking and bogging

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I drive a 2013 BMW 135i convertible (former life as a dealership loaner car). Over the past several months, I have experienced a problem with the engine in two ways: when stopped or slightly rolling forward, the engine does something like “dieseling” and lurches forward a bit. Also, on a stop and go situation like a right turn on red, the engine on acceleration bogs - no response for 1-2 seconds. I’m thinking it may have something to do with the turbos. In any case, it doesn’t feel right and is potentially unsafe. Thoughts? It’s under warranty, but the dealership doesn’t seem to be able to fix it.

I assume ur car has electronic throttle body? Could be bad pedal pos sensor or throttle body sensor also. But u would expect a code for that. Did u see the bmw video where they dismantle newish cars prior to crushing? Gotta be some type of warranty return/devil cars. I like it when they blow all the airbags in sealed tent.

You might post this on a BMW forum. That engine is used in lots of them, somebody might have had the same thing happen to them.

Have you elevated it to BMW America? They may have a solution for the dealer.

I’ve had a similar problem on my Corolla, driving slow in neighborhoods and making turns it would sort of jerk around the corner, speeding up quickly w/just a slight press on the pedal, and slowing down just as quickly, w/a jerk. That turned out to be a combo of the throttle position sensor and the fuel injectors were a little dirty.

When you let your foot off the gas the engine computer completely shuts off the injectors, to get better mpg. Then it turns them on in time before the engine stalls. But if all that isn’t working smoothly, this jerking behavior in slow speed driving can result. Not the only cause, but something to consider anyway. Ask your shop to double check the throttle position sensor is properly set up and working, and maybe do some fuel injector cleaner treatments. I just used some stuff you add to the gas tank. Worked for me anyway, no more jerking/bogging.

A good number of bmw sites describe the issue. Replacing all the injectors seems to work. Issues with hpfp which I assume means fuel pump is a good area. There is a hi sensor in fp assy and a 2nd sensor under hood? Issues with “loose” throttle body is mentioned. Loose? Some say remove valve cover and check for crud from coked up oil from turbos?

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