radiator boiling over

JReichert

i have a 2000 ford ranger with a 3.0 v6. started running hot so i checked the coolant there was none in the tank so i added some. it still runs hot and after driving for a little i can hear the coolant boiling and eventually boiling over. no apparent leaks that i have noticed any suggestions??

BryantS

Does it overheat with the cap off, clearly not driving but just idling? Do you ever hear you cooling fans come on or does it have a clutch fan? If a clutch fan can you spin the fan very freely? Do you also have a misfire on startup or any other time? Does it smoke at all?

ianc435

Heres is a list of overheat problems take you pick.

Dirty radiator, bad water pump impellar rotted, trany not shifting correctly, head gaskets blown( combustion checker with fluid.)
If you thinks it head gaskets. Pull plugs and compare white deposits on suspect plug and clean piston head indicatebhead gasket.

lorel

Any time a engine indicates it is getting hot..shut it off NOW! its possible that a thermostat, radiator, radiator fan, radiator fan switch has failed and the engine now has lost water circulation. If you contine to drive it like this, the engine will start to over heat. With a aluminum head, aluminum expands at a faster rate then the cast iron block. In this case, the head will warp, and head gasket integrity has all but been lost. You will have either antifreeze in your oil, oil in your anti freeze or combustion gas going into your cooling system causing the boil over condition that you might have.

It is imperative that if a engine indicates it may be overheating to pull over and shut the engine off and let it cool. check for antifreeze that is missing. Check for coolant flow "put hand on radiator upper hose to see if its warm or hot" cold hose means thermostat is not open or water pump impeller has been sheered.

Lorel,

Automotive technician

dirtrider73068

I would say water pump could be bad, or a stuck closed thermostat.