(Image: Header Graphic)

Wednesday, December 6, 2023

Doug's Domain

Doug Vetter, ATP/CFI

Like what you see?

Donations to dvatp.com are now processed via Stripe. Like this site? It's easier than ever to show your appreciation.

Sunday, May 4, 2008

Aux Cooling Fan Replacement

(Image: New E36 Electric Auxiliary Fan Installed) As expected the aux fan arrived from Koala Motorsport this week. I was so busy this weekend with more pressing regular life matters I almost didn't get the time to install the part, but I managed to get the other work done ahead of time and install the new fan.

While the BMW TIS suggests you need to remove the bumper cover to remove the fan and frame assembly, that is incorrect. I just removed a few protective panels attached to the bottom of the bumper cover and six screws on the fan assembly itself and the fan assembly slid right out the bottom of the car.

I stopped by the dealer earlier this week to get a quote on the work. It turned out that if I knew nothing about my car and just walked into the dealer to get this done my wallet would be lighter by a whopping $805 rather than the $250 it cost me to buy an aftermarket part and do the job myself. Unlike most jobs where labor dominates the cost the vast majority of this repair is sunk in the cost of the part, which is a staggering $642. That's just crazy. I see no reason to buy the OE part when the aftermarket part looks and appears to function identically to it.

I took apart the old fan to figure out what failed. The rotor (rotating assembly) of the electric motor was in good shape, but the permanent magnets that surrounded the rotor were broken in several places. Moving the rotor back and forth caused the magnet fragments to move around and bunch up with each other. This caused a lot of friction in the rotating assembly and frankly I'm surprised the motor actually worked in this condition. Hello, garbage man? I have a ten year old aux fan for ya...

Now for the fun part - cost analysis. Retail price for the OE fan is $642. I paid $240 and change + shipping, or $252 total. This is a savings of almost $400. The quote at the dealer for this job was $805. $805 - $642 = $163 in labor I saved by doing this job myself. The total savings is obviously $805 - $252 or $553. Not a bad payday for a few hours of research and wrenching, don't you think? DIY. It's the thing to do. Seriously.

Mileage: 159633, Parts: $252, Parts Saved: $390, Labor Saved: $163