Cooling fans damaged

First post here; I've poked around but never joined up until recently trying to track down some information regarding the subject line. Purchased my 97 Passat last year as a commuter car and it has paid for itself in fuel costs in that time.

So, of a couple of problems here and there, this is the biggest one so far: the trailing edges of both fans are damaged and make an awful racket after they begin running on high speed. Also, I get a vibration when they are running on low, AC on or off. Others have noted the shroud component fails and can cause fan damage. I suspect this is the case, but I can't seem to find anything in the assembly to contact the fans. They may just be out of balance from the damage, I suppose. I'm curious if anyone has any ideas regarding this and where/what to check.

I'm going to replace the fans and belt before they fail the rest of the way (parts already ordered). Does anyone have a write-up (or can point me to one) on how to disassemble the fan assembly?

Welcome
I would guess you're on the right track for the vibration. Although these aren't really complicated components if the blades are damaged they can cause an imbalance that could be felt inside the car.

Everything I've read / looked at suggests that the front end has to be dismantled in order to get the fan assembly out. Since it's bolted to the inside of the radiator it follows that you need to unbolt it from the radiator in order to remove it. Also, bear in mind that the AC line from the compressor crosses the top of the fans / radiator when it goes to the AC condenser. I'm not sure but you might be able to unbolt the condenser and lift the assembly out of the way so the fans will come out.

Others might have suggestions too, IIRC there was a thread asking this question a while back.

Steve

They can be worked out without removing the front end, but it's a pita. I cut the shroud slightly to make the holes, notches on the driver side. This way you don't have to fully remove the lag screws, if there's ever a next time...

On both of my B4s, there was a plastic ring around each fan, thats attached to the fan shroud. I can only imagine they're supposed to take up any space between the blades and the shroud, for higher efficiency. Both rings were detached and bouncing around. I removed them and saw no changes in cooling.

I think I cut them in pieces and removed them, with the shroud still mounted in the car.

-Todd

There was a recall some time back in the 90's where we had to replace the belt that runs the small fan from the large one. The official way is go remove the rad support and cross member from under the car and drop the fan housing from under neath. It's not too bad if you have a lift and can support the engine, but if you don't have a lift and engine cradle, the best way is to remove the front end- bumper cover, bumper etc to access it that way. You may still have to remove the top AC pipe from the condensor though.

I just had to replace my second fan on my mk3. I think I got one of the last ones from VW, the label was not even close to white- more like dark brown and the plastic bag was decaying

Managed to get both the master and slave fans replaced today by pulling the bumper, grill, and support. It was a pain, since I refused to disconnect either radiator or AC lines, but it is manageable. I stuck cardboard against the rear face of the radiator to cushion the fins as I removed the fan/motor. The source of the vibration was definitely from chewed up fan blades. Also, the awful racket was from one of the fan shrouds (lips?) that was cracked/loose. Thanks for your help guys.

Now, to send this old dog on to a new home now that the wife and I scooped up a couple of mk6s.

ToddA1 said:

They can be worked out without removing the front end, but it's a pita. I cut the shroud slightly to make the holes, notches on the driver side. This way you don't have to fully remove the lag screws, if there's ever a next time...

On both of my B4s, there was a plastic ring around each fan, thats attached to the fan shroud. I can only imagine they're supposed to take up any space between the blades and the shroud, for higher efficiency. Both rings were detached and bouncing around. I removed them and saw no changes in cooling.

I think I cut them in pieces and removed them, with the shroud still mounted in the car.

-Todd

Click to expand...

Todd, can you go into more detail of how you accomplished this, preferably with photos? I need to put a new V-belt in mine.

The notching of the holes?

I'm not pulling the shroud anytime soon, but just take a cut off wheel and remove the bit of metal that's closing the hole, on the outer side.... just on the driver side. The hole becomes a slot.

If you're just looking to tip the shroud back to install the belt, I wouldn't bother. You'll curse trying to get the shroud out of the car.

-Todd

I won't talk too much, see images.
Here is what I disassembled for radiator fan to pull out.
--------------------------------------

--------------------------------------------------------------------
Pulled out this way, turned back this way, no issues (be careful a bit more with the upper condenser tube/pipe).
-----------------------------------------------------------------------------

-------------------------------------------------------------------------------------
Carefuly. Two more hands are appreciated a lot!
--------------------------------------------------------------------------

------------------------------------------------------------------------------------
View from the front...
---------------------------

---------------------------------------------------------------------------------
...and from above.
--------------------------------------------

-----------------------------------------------------------------------------------
ToddA1, here is how I solved the problem with the
plastic rings around the fans... a little bit of PU adhesive & sealant + bolts, self secured nuts and washers.
And voila! (the tape on the left was for secure bonding).
---------------------------------------------------------------------------------------------

------------------------------------------------------------------------------------
The other side.
-----------------------------------------------------------------

----------------------------------------------------------------------------------
I hope I helped a little bit, good luck!
P.S. Do not forget to clean up the condenser and the radiator (and do not
hesitate to split them as wide as you can while cleaning up their inside
areas), I did it with what I had at the moment, garden hose (water) and
compressor (air) (borrowed) Looooot of cr*p is there, you won't believe it!

Did you gain anything from pulling the rad support? Other than the upper plastic shroud, it doesn't appear that it gave you any more wiggle room, unless you're able to tip the rad and condenser core forward more.

My plastic rings were broken, so I wasn't trying to fix them. Honestly, I didn't notice a difference without them.

Tonight, I cleaned the condenser core for my home AC system. Hosing it down is ok for most dirt, but oxidation will build up that hurts heat transfer. There's also oils, pollen, and a lot of other junk that water won't get off.

I used an alkaline based core cleaner that foams and brightens the metal. The stuff is nasty and can cause chemical burns. I felt it making my hands slippery as it was breaking my skin down. Nasty fumes, too.

I'm thinking I'll do this to my rad, and condenser the next time I have them exposed. As mentioned the stuff is nasty and may pull the paint off the condenser. I'll dilute a bit more to be safe. Heavy degreaser may do the same thing. It'll etch AL and other soft metals, if you're not careful.

There's also a rinse free evaporator cleaner on the market.

-Todd

Nice job, LLL! Thanks for all the pics.

I'm just gonna try tilting it back for installing the V belt. But that also means I can't really clean it out, either. I'll blow some air through it to see if any debris comes out though.

Got this job done last night, and I had to do it EXACTLY like LLL did. I got the V-belt changed, and can confirm there is not enough room to get it in there without removing the top rad support. It only takes about 20 minutes to remove though if you know what you're doing. Take off the front clip, headlights, eight bolts holding the support to the car, two bolts on the hood latch, and the two long bolts holding in the rad assembly.



Remove the two bolts on the back right (passenger's) side of the assembly that hold the fan shroud to the radiator. You will be able to pull it apart a couple inches on that side.

Loop one end of the belt on the motor side



Then use a clothes hanger and get it hooked on the slave side. Rotate gently to get in the pulley.



Now then - there are few pictures past this point, because I was half sick with a headache. But I took the car out for a test drive, and came back to find only the master fan was turning again. This got me pretty disgusted, but I pulled the whole thing apart again. This is what I found:



Although it didn't feel like it initially, the slave fan bearing was shot. I could really tell at this point, because I could barely get it to turn either direction. The nose of the master fan had literally spun and melted. It also flatted out my radiator fins a bit, but only like a 1" area.

So this time I pulled the whole thing out like LLL did. Take out all four bolts holding the radiator, fan shroud, and AC condenser to each other.



Separate it all, and gently work that shroud out of the car. Be sure you have help! Listening to the radiator crinkling at times was certainly nerve-racking.

For those of you who might remember, I once had a parts Cabrio that I saved the radiator assembly from with perfectly working fans. I found out that these fans would transfer, but the master fan is about 2" smaller in diameter than what was in it. So now I have two working fans again, but one is a little on the small side. What do you think -Better than just one big fan? If this doesn't seem to work well for whatever reason, I'll probably try fitting in a pair of low-profile electric fans later on.

I posted in your other thread that I'm running a smaller Jetta fan. Been like that for a few years.

Not ideal, but I've been too lazy to swap it out.

-Todd

ToddA1 said:

I posted in your other thread that I'm running a smaller Jetta fan. Been like that for a few years.
Not ideal, but I've been too lazy to swap it out.
-Todd

Click to expand...

Good to know, I'll probably be fine then.

Now I just need to get my AC recharged. It's only getting down to about 60 degrees. Never found a leak with my uv light though.

Did you gain anything from pulling the rad support? Other than the upper plastic shroud, it doesn't appear that it gave you any more wiggle room, unless you're able to tip the rad and condenser core forward more. My plastic rings were broken...

Click to expand...

Yes ToddA1, I did gain some space, not too much, but enough to work more comfortable.
I had broken plastic rings too, but I glued/bonded them and put them back
thechoochlyman, nice job! Any fan is welcomed, bigger or smaller (just to fit the place) than no fan. I think you'll have no problems with it, because when my belt was broken, I was driving on the hottest days (+40°C) with AC on and only one working fan... all that I noticed was slightly higher temperature which after turning on the third fan speed got lower to normal. So I think you'll be fine.
Don't forget to adjust the headlights! Good luck.