BMW E60 M5 – Malfunctioning Throttle Actuator
The BMW M5 has always been considered one of the best, if not the best “all-rounders” ever produced, and many fans of the model believe the E60 generation (the last of the big “S85” V10 engines) to be the greatest of all. The combination of performance, practicality, and quality of the BMW M5 have become legendary over its 30+ year history. But like any car, no matter how good, it is not without its own handful of common problems and repairs as age and mileage both take their toll. One of the more common problems that many “E60 M5” owners experience is a malfunctioning throttle actuator.

There are a total of ten throttle butterfly valves (one for each cylinder) that control the engine’s air intake, arranged in two banks of 5 which are connected by a common throttle linkage. Each bank of five throttles is controlled by an electronic throttle actuator that opens and closes in response to your foot pressing or lifting off the accelerator pedal. The internal mechanism of the actuator is comprised of small gears and cogs of interlocking teeth. Over time these small teeth wear down and eventually reach the point where they are no longer able to engage with each other, rendering them unable to operate the throttle valves correctly.

How to tell when your throttle actuator needs to be replaced.

When one or both of the throttle actuators fails, sensors in the pedal and engine then tell the on-board computer that the throttles aren’t opening according to the pedal input. The engine management system, called the “DME,” engages a fail-safe precautionary mode, often referred to as “limp-mode”, during which the engine power is drastically reduced to prevent damage to vital internal engine components. The “SES light” (service engine soon light) will also turn on in the instrument cluster to alert the driver of the problem so they can get to a repair shop. One good way to determine if it is, in fact, the throttle actuator that is causing the limp mode is (while the vehicle is off) disconnect the throttle linkage from the actuator and turn the actuator cam by hand. If you hear and fell a tell-tale clicking or clunking, it’s a pretty sure bet that you’re now in the market for a replacement throttle actuator.

Does your BMW need a new throttle actuator or diagnosis for the SES light? Give us a call today to speak with one of our service advisers.