E39 M5 Aftermarket Fan Clutch
In my last Wheels post I detailed extensive maintenance work on my 2002 E39 M5. Part of that work was replacing the radiator that came with the car. I expected this replacement to make my car run cooler.
It did, but not to the extent I thought it would. By unlocking the cluster, I can track the coolant temperature much more closely than the gauge does, and it was still hitting the mid-to-high 90s Celsius on warm days. I was resigned to buying a very expensive replacement BMW fan clutch to try and remedy. But then I read a post in the E39 M5 Facebook group.
A fellow owner was also experiencing high temps, as well as vibration and power loss. He said he solved it by purchasing a $45 aftermarket fan clutch off Amazon. This seemed incredible to me, but with firsthand testimony and a price difference of over $300, I thought, why not try it? Other owners chiming in on the lower quality of recent genuine BMW parts also made the decision easier.
Replacing the fan clutch in an E39 M5 is not difficult. In fact, it’s easier on the M5 than any other E39 model. You simply reach down to the front of the water pump with a special tool, hold the pump in place and reverse wrench (rightly loosey) to remove the fan and clutch. Here’s an excellent tutorial from FCP Euro with chapter and verse.
The result has been dramatic. My M5 is running about 10 degrees Celsius cooler than before, never getting out of the 80s and, most of the time, staying below 85 C. That is the temperature required to set the gauge needle to the 12 Noon position. I’m amazed a replacement fan clutch can make that much of a difference, never mind an inexpensive aftermarket part. It’s only been a couple of weeks so I can’t speak to durability. Even if the fan clutch gives out in a year, I think I’m still way ahead.
While I was at it I replaced a broken rear corner sun shade on the passenger side that had lost all tension. Years ago I repaired the one on the drivers side, but this one was broken beyond repair. If you can believe it, a new one from BMW costs over $900 – for a piece of plastic with a spring in it! Here again the wisdom of the crowd served me well. A fellow owner with a side hustle selling parts sold me one for $225.
So that’s my E39 M5 aftermarket fan clutch story. No way I expected it to make such a difference, but it did, so I’m passing the information on. You need to stay open-minded and creative when maintaining these late-model classics. Happy fall!
