Vandit

So i'm removing my alternator/cooling fan assembly to replace my cooling fan (anyone want to guess why?)

I'm following this how-to from P-Car
http://p-car.com/diy/vbelt/

I'm at the point of removing the three fasteners from the alternator assembly

The DIY link shows 3 hex bolts


However, my car has this


The nuts appear to by 10mm.

Was this a different between the 964 and the 993?

I'm guessing the next step is to remove the three 10mm nuts?

-nick

I think there was a change from bolts in the fan bearing to studs (or vice-versa). I remember when I replaced my bearing that the new one was different than the original. So yes, take off the nuts.

ps- Gnarly fan. What happened?

Vandit

I'm not sure what happened, as the car was like that when I bought it. The PPI mechanic told me it looked like something had been caught in the fan at some point.

All the cracks appear to be old and not spreading in my 8mo of owning/hard driving.

I'm going to replace it anyway and get around to some other things while I'm at it.

jimq

The fans can delaminate. I had to replace mine a couple years ago as the blades were coming apart at the tips.

AOW162435

The fans are magnesium and have a pretty tough finish from the factory. Unfortunately, some things can cause the paint to fail, such as debris sucked into the fan, or failing alternator/fan hub bearings. With very little clearance between the ends of the blades and the interior of the housing, the blades start to rub the paint off. Once the magnesium is exposed to air (and the moisture in it), it will start to slowly fail.

In addition to Jim's fan (thanks again), I've had at least 20 others on my workbench over the last 5 years. Unless brand new, every one I've seen has some form of corrosion, splitting, etc.

Here is an extreme example of what happens when the blades let go: Failed 993 fan


Andreas

Vandit

Man, looking at that 993 fan failure makes me feel foolish and fortunate about my fan. I was seeing lots of 6k+ all of yesterday at the autocross.

Here's more pics of my now removed gnarly fan.















Looks like it rubbed on the housing at some point or another. I wonder if that caused the cracks towards the center too.

I already sourced a new/used replacement from a member on Pelican. It's painted, but i'm going to have it powdercoated before re-install. I'll getting the fan housing powdercoated too.

SophieJ

1995 993 C4 Australia . Recent replacement of impeller due to cracks at the base of two blades with the tip of the worst affected rubbing on shroud. Suggest age related failure of impeller due to aviation type fatigue of blades. Recommend checking impeller carefully in this age group. All the best.

kkswow12

i havenät heard of these kinds of failures in g modells, but then , havenät been looking, is there a parallel universe here? also magnesium?, anyway, i am buying a new one...canät trust used product as paint probably hides the early stages of this disease, so, new=peace of mind....

DobermanDad

It'd be sweet if there was a billet option for the fan.

AOW162435

I'm holding out for a titanium replacement.



Andreas