[V6-12v] Radiator Fans not switching in correctly...

[Chris Thorp]

On Sep 6, 2006, at 4:18 PM, The CyberPoet wrote:

> You can't tell by simply rattling it. You could tell by pressurizing
> it, but the only easy way to do that (that I know of) is to overheat
> the car, which is definitely not something you want to do if the cap
> has failed!
I always just squeeze the upper radiator hose when cold and again  
when fully warmed up.  If the hose is (much) harder than when cold,  
then the cap is likely good.  Slightly more dangerous, would be to  
fully warm up the car, turn it off, and then slightly open the  
radiator cap.  If it's holding pressure, you should get a bit of hiss  
and you should hear the coolant start to boil.  DANGER: IF YOU OPEN  
IT TOO FAR, YOU'LL ALLOW THE BOILING COOLANT TO FORCEFULLY BE  
EXPELLED...  Put a large towel over the cap before you try this.   
It's saved me in the past.  YMMV, etc.

-Chris