Help! Engine malfunction:reduced power. stuck in Chicago

[Sophisticated Redneck]

Originally Posted by Haneifk

so they wouldn't take it back. The friend of a friend who's a lawyer ended up correcting themselves saying i could make them take it back in court only if they refused to fix it. But they told me they would fix it and ship it back to me. They just called me today saying they replaced the turbo wastegate solenoid and a few hoses i asked for a list of work done and parts replaced so i'll see exactly what they did once they email me. Also plan to take it BMW as soon as it arrives for a full inspection for peace of mind. anything else i should plan to do once it arrives? sell it? lol

sophisticated redneck: thank you for all the info! you mentioned how the wastegates can be adjusted. is there a way i can check too see if they adjusted vs replaced them?

happy to help but The term they used "wastegate solenoid" is kinda of generic term and doesnt sound like they replaced the wastegate actuator. To better understand I'll explain a bit (you may already know this but might be helpful to others): The Wastegate actuator is just that: its purely mechanical and not electromagnetic like Solenoids. It functions from the vacuum generated by the vacuum pump on your engine.

How much vacuum is controller by the pressure converters which are actual pulse-width modulated solenoid valves (fancy way of saying electric current is turned on and off really fast to adjust how much these valves open) These solenoids determine how much vacuum the wastegate actuators see and can go bad from time to time.

You also have the diverter Valves, which are another solenoid operated valve that open to relieve pressure when the throttle is closed and the turbos are spun up, allowing the turbo boost pressure to be redirected to the pre-intake turbo manifold (this is what makes those cool turbo noises) so you dont blow off an intake tube due to overpressure. If the diverter valve is leaking, it can cause the errors you were seeing too as the boost pressure will be leaking right into the pre-turbo intake stream.

So ask them for a more detailed description but I have a feeling its your pressure converters or Diverter Valves, the actuator itself rarely goes bad its such a simple device. Either of them are only around 100 dollars each and can be replaced by anybody handy with a wrench, so if the others go bad in the future, you can easily do it yourself if you wish to.

If it were me, this would be a red flag but not enough to return it as the car is near 7 years old with 60K, stuff like this goes bad from time to time. HOWEVER this is a 100,000+ dollar machine when it was new and you can easily sink tens of thousands in repairs if something serious goes wrong so definitely take it to the dealer and have it gone through and then make the call weather to keep or sell..Thats what I would do anyway.

BTW, if you decide to keep it, welcome to the fold!