Skip the auto shop - Our mechanics make house calls

Q: Engine RPMs drop suddenly from 2500 to 500-1500 RPM on 2013 BMW 650i

asked by on

Under moderate to heavy acceleration, my car will lose power. If accelerating anywhere over 2500 rpm, after accelerating the engine rpm suddenly drops by 500-1500 rpm. Then it continues to accelerate from the lower rpm. It happens only once each time I press on the gas pedal. There are not any codes that appear. The dealership has examined the problem and they have not been able to find the cause. They ran fuel pressure tests, vacuum leakage tests, and might have checked the throttle position sensor. Can you tell me what is causing this and how to solve the problem?

A: Thanks for writing in about your 2013 BMW 6...

Thanks for writing in about your 2013 BMW 650i. The symptoms sound similar to a vehicle with a throttle position input error or a major boost leak in a forced induction vehicle. To verify this, I would recommend having a professional, such as one from YourMechanic, diagnose the loss of power problem in order to have this repaired properly.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Save up to 30%

Get a quote

What others are asking

Q: Car not accelerating when first started

Hi there. When you let your car sit for a long period of time the gasoline tends to lose its combustibility. Along with sediment settling in your tank this will cause your vehicle to not perform properly. Also a malfunction...

Q: RPM revs high

Hi and thanks for contacting YourMechanic. Check the IAC (idle air control valve) to the engine. This will cause the RPM's to fluctuate up and down to a dramatic amount. Look at the wiring to the IAC and make sure...

Q: As I drive, the door locks and keep locking and unlocking, and acceleration seems sluggish.

Hello, thanks for writing in. Most of the time this is due to a bad connection or a failing ignition switch. If this is occurring with the locks as well as a power loss then you may have a bad...

Related articles

P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the P0052 code means This code is seen when the Engine Control Module (ECM) tries to control the...
P2428 OBD-II Trouble Code: Exhaust Gas Temperature Too High Bank 1
P2428 code definition A P2428 trouble code signifies that the PCM has detected a problem in the exhaust gas temperature sensor circuit in bank 1, which subsequently contains the number one...
P2103 OBD-II Trouble Code: Throttle Actuator Control Motor Circuit High
P2103 means there is a fault with the throttle actuator control motor circuit, likely due to a defective electrical component or part.