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Old 07-14-2012, 12:16 AM   #29
2nd Gear Member
Join Date: May 2011
Location: Toronto / Waterloo
Posts: 261
I guess it's time for me to update this thread since there's a lot of activity here! I have a parallel thread on bimmerforums.

I replaced the clutch fan and re-connected the overflow hose. I couldn't get any of the three Princess Auto representatives I contacted to find me a fan tool over the phone so I decided not to make the huge trip to missisauga to chance not finding it. I called NAPA and Partsource but searches came up dry. Ended up going to a local garage who cracked my fan clutch loose for free =).

Anyways, through the repair, I found out three things:
1) The overflow hose sends a LOT of coolant into the reservoir if you overfill the reservoir.
2) I had a lot of air in my system (bled it) using the bleeder cap and letting the car run for about 20 minutes. Lots of extra coolant came out of here (overfilled the expansion tank).
3) My fan shroud has a tendency to come loose. Prior to my fix, I found my clutch fan not moving at all. Thought the clutch fan part was completely obliterated but when I took it off, I noticed that clutch fan was still good and had no play in it. This means that the fan should've been spinning. Weird, I thought.

After putting on the new fan and fan clutch, I drove for a bit only to find that my new fan had stopped as well. I immediately noticed that my fix had undone itself and that the overflow hose was jamming the fan, cracking a new blade (noo!!).

It was unclear how this happened, but I found my shroud unmounted from the rad (Even though the side rivets are still good) and the entire thing had shifted into the way of the fan.

My remedy so far has involved discovering the following:

1) Fixing destroyed overflow hose clips on fan shroud:
The original hose mounts on the fan shroud were destroyed, so I drilled some holes in the shroud for zip ties. These zip ties can hold your overflow hose. This must be done if your fan shroud's clips are cracked.

2) The fan shroud unseated itself (top plastic clip is intact but somehow came off of the rad).
This was really weird. Furthermore, I realized that I had no idea how the bottom of the fan shroud mounts to the rad.

Fixing #2 involved drilling a hole through the fan shroud's plastic clip that holds on to the rad. I took a screw, washer and nut and fastened the shroud to the rad firmly from the top. Reinstalled the plastic rivets on the side.

Took the car for another test drive and I don't appear to be losing coolant or anything. As I parked back home, I did not turn off the car. Popped the hood to see if my fan got jammed again (just to check). It was fine. Got back in the car, reversed and repositioned my car. At this point, I suddenly started hearing a periodic thub-thub-thub-thub noise. It seemed to be coming from the vicinity of the fan. I have a feeling the fan shroud got loose at the bottom and that the fan is brushing agianst something along the bottom of the shroud.... but I've no idea.

Any ideas on how else to ensure my fan shroud does not come loose and what a fan-related thub-thub-thub noise is?

Last edited by limenuke; 07-14-2012 at 12:18 AM.
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