September 7, 2010

My Garage - Replacing the Secondary Fan on the Passat W8

Well, the secondary fan on my W8 finally gave up the ghost the other day so I decided to bite the bullet and replace it myself. The challenge, there is really NO SPACE between the serpentine belt and the radiator to perform any kind of work.

So I ordered a new fan from 1st VW Parts and got it a matter of a few days:

I did some research on and Passat World. and figured out how to slide the Lock Carrier forward to the service position in order to free enough space to get the fan out. The process is well explained on those sites so refer to them for a step-by-step procedure. My main concern was if there would be enough flexibility on the hoses so that I could minimize having to disconnect anything or drain fluids on the W8. It turned out that both the AC condenser as well as the ATF oil cooler have flexible connections with enough freedom to allow sliding the Lock Carrier forward a few inches. Enough for me to do the work. I could not find the 120mm long bolts as suggested in the online articles but discovered that two 70mm bolts were long enough for what I needed.

So the grill,  bumper cover, bumper bar and lower engine cover had to come off as it normally does for any work related to the front of these cars.

Here are some diagrams for reference:

There are a number of screws that need to come off in order to slide the Lock Carrier:
  • Remove the screws on both sides of the top of the Lock Carrier.
  • The three screws that secure the plastic intake duct also need to come off.
  • I removed the headlamp assemblies as well. Only the one on the driver side is really in the way but I wanted to clean the whole front of the car since it was already open.

  • I also removed the headlamp washer assemblies as the hose connecting to the windshield washer tank appears to be a bit too short.
  • The screws connecting the bumper cover support to the Lock Carrier also had to come off.
  • Most importantly, the bumper support bolts have to come off. One of them needs to be substituted with a long bolt (or the VW Tool# 3411 if you can get one) that can support the Lock Carrier as explained on the links provided earlier on this post.

  • I disconnected the Oil Cooler from the Lock Carrier and supported it with a jack stand as it does not need to slide with the rest of the Lock Carrier.

  • One of the challenges of this procedure is that someone at VW in their infinite wisdom decided to locate one of the fan screws behind one of the temperature sensors. I mean, come on, what about CAD and superior German engineering (FIAL!) So, I ended up removing the sensor in order to gain access. This requires draining a little bit of coolant or at least capturing as much as you can from what is going to leak when removing the sensor.

  • I traced the wire leading from the fan to the area next to the coolant overflow tank.

  • Removing the fan involves undoing the three screws used to attach it to the LC and removing the connector cable. The cable is THE MOST PAINFUL PART of this project as it is routed via the lower part of the LC and then up on the driver side, finally surfacing under the driver-side headlamp assembly. The part of the route on the driver-side of the LC turned to be pretty difficult to reach with the LC on the car.
  • Installing the new fan required the reversal of theses steps. Fishing the cable via the original route with the LC on the car turned out to be a painstaking task but doable (be patient). 
The car is back on the road so I took it for a "test drive" down to the Columbia River Gorge.

Yep, it is all good in W8 land. For now anyway ;-)


  1. Well done!
    Is this the same secondary fan that my local VW dealer wants $1,100 for? I've been driving without it for years and no problems so far (other than annoying check engine light which may or may not be due to the fan).

  2. Great tutorial. Thank you. # things to add if I may: 1.) Oil cooler can be left affixed to the CL by the anodized mounting plate plate. Simply remove the (2) 10MM bolts on the left backside at the top and bottom. 2.) the removal of the temperature sensor at the radiator outis spot on. Watch out for the silver o-ring that with fall into your catch container. This must be reinstalled. 3.) Insure to align the bumper affixing bolt washers exactly with the original marks made when torque by VW. This will insure exact re-fitment of the bumper cover as well as proper gaps at the finder and headlamps.

  3. For future reference, if you use a T30 bit with a 1/4 open ended wrench you can take that screw off without removing the temp sensor.