Hey guys I have a problem where my overflow tank will slowly fill up and spill. The car is only idling when I test it, so not much air flow. There is no white smoke coming from exhaust, no coolant in the dip stick and none under the oil cap. No champagne bubbles on start up also.
I tested radiator pressure using about 13psi and left it alone for 1hr and 30 min and not lost pressure.
Helpd presure for over an hour which is good
No coolant under oil cap
I believe my fan clutch might not be working properly, I tried using a piece of paper to slow down the fan and it does slow down fairly easy, also not much resistance when I spin it when warm.
Anyone know a cheap replacement fan clutch?

Any other test I should do?

 

replace the radiator cap, they don't last forever.

while you're there, make sure you didn't make the rookie mistake of using the flat cap that is supposed to be on the engine and placed it on the radiator.

 

What RE said and also the hose that runs to the overflow, because if that is bad, the system won't draw the coolant back in when it cools down.

 

a cheap replacement would be to find another used fan clutch from someone who went with an electric fan, it doesn't seem they fail that often...

 

a fan clutch wouldn't push coolant into the overflow though, maybe after the coolant seals let go though i suppose it is possible.

 

Thanks guys,RotaryEvolution my radiator cap was slowly leaking. I replaced it. I still believe my fan clutch needs replacing but for now it seems its running well.
Im just glad there is not coolant leak.