Failing Condenser Fan - Heavy Duty Shakes At Idle

[PorscheServiceThen529Plan]

There is a rumble that shakes the car at idle only when snowflake/ compressor button is on. Source is right behind driver side headlight. I am thinking based on some research (and very thin actual knowledge) that it must be a condenser fan failure. Does this sound right? If so anyone know if this is an easy/intermediate fix? I have not tried doing much since working on old british leyland engines which were lawn mower engine complexity, but would like to try tackling harder things. thanks in advance

[Loren]

Sounds likely - but test and see first as sometimes the (large) ballast resister goes bad.

Not a difficult DIY either way.

[PorscheServiceThen529Plan]

OK both low fan relays pass the fingertip click test when I turn ac on. No fans with ac off. With ac on, passenger side fan works, but drivers side fan does not. So sounds like drivers side ballast which I will order but why does all the sound come from pass side where fans works? Also thought I saw in another thread that when you turn on ac the high fan is activated not the low (as in ballast resistor for low would not matter) but that cAnt be right if your are supposed to finger tip test the low fan relays when starting ac. Many thanks for the guidance. Will buy Bentley mAnual to reduce ignorance on these questions. Thanks

Edited January 11, 2014 by PorscheServiceThen529Plan

[Loren]

This might help...

http://www.renntech.org/forums/tutorials/article/40-removing-and-installing-ballast-resistor-for-the-radiator-fan-motor/

[PorscheServiceThen529Plan]

Thanks Loren Does it seem likely that the fan failure on the driver side could be causing the heavy shaking that is most definitely coming from the passenger side radiator? Do I have two problems? thanks, Todd

[JFP in PA]

Thanks Loren Does it seem likely that the fan failure on the driver side could be causing the heavy shaking that is most definitely coming from the passenger side radiator? Do I have two problems? thanks, Todd

I think you need to access the fan itself; it may either have something stuck in it or possible thrown a single blade, which makes them shake like Hell. If you have access to a Durametric system (or PIWIS/PST II) you can test activate the fans to see if they are operating correctly as well.

[PorscheServiceThen529Plan]

Thanks JFP. Turns out it is the passenger side fan. The fan blade rotor is loose - I can push it back and forth / it is loose along its axis just enough to develop a surprisingly harsh wobble. I am guessing this means a new rad fan unless maybe I find something that could be tightened up? Maybe I get away with just new motor? Also driver side fan does not work at all but relay is fine and blades spin freely so I am guessing that is ballast resistor. Thanks

[JFP in PA]

Thanks JFP. Turns out it is the passenger side fan. The fan blade rotor is loose - I can push it back and forth / it is loose along its axis just enough to develop a surprisingly harsh wobble. I am guessing this means a new rad fan unless maybe I find something that could be tightened up? Maybe I get away with just new motor? Also driver side fan does not work at all but relay is fine and blades spin freely so I am guessing that is ballast resistor. Thanks

I do not think the fan motor assembly is rebuildable, plus you would not want to repair it only to have it crap out 5 min. after the car is back togeather.

[PorscheServiceThen529Plan]

Anyone know if you can replace the fan motor/blade assembly without removing the radiator? Looks maybe possible to unclip the fan housing from the radiator, (maybe even remove it? and then get to the motor and fan to replace it, but maybe its too tight without removing the radiator? I broke off half of the plastic housing cover (the part that covers the back of the motor) trying to pop it open in place. Not sure if its worth it but if I take housing out I will epoxy the broken cover piece back in place and reinforce the joint with a strip of glass mat (not pretty but should be plenty strong).

thanks,

[Loren]

Remove the wheel on that side and then the wheel well liner (see my 3rd Radiator Mod in the DIY Tutorials for that) - then you will see everything for replacing the fan motor etc..

[PorscheServiceThen529Plan]

So off with the front bumper it is. thanks!

[Loren]

So off with the front bumper it is. thanks!

Negative -- I am suggesting going through the wheel well.

You should have enough access without removing the bumper.

[PorscheServiceThen529Plan]

So i got the replacement radiator fan from suncoast and it was not bad replacing the old one. Took a little work to get the fan support bracket out but all went fine. The DYI was very helpful and bentley manual was good too. Hooked up the old fan to a drill battery just to see how bad it was and it nearly shook the bench apart. New one is nice and quiet. Now i need to trouble shoot the driver side one but am pretty sure its the ballast resistor because relay clicks fine. Have figured that the white wire is pos high speed and green is low pos. so i will test driver side fan with drill battery in place to confirm resistor vs motor issue. Many thanks for the help!