Problems with engine cooling WTF?

[ghs215]

It's 110 deg F here in Phoenix and my 4runner is running hot sometimes. Coolant is 1 year old. It gets to about the 75% mark then comes back down to normal, only a couple times. I thought it was the fan clutch, so I swapped that with a new one (2 days ago). It has not happened again...

What I don't understand is why my radiator hoses are not hard as a rock...I can squeeze the sides together (HOT! Ouch). I don't think this is normal since my other 4runner is hard as a rock. The coolant level is normal and hasn't changed, no signs of boiling over, no signs of leaking, water pump looks ok.

What is going on here?

 

[Jagerzel]

Maybe a stuck thermostat?

 

[Brian3676]

If a new fan was installed and it has not over heated again, sounds like you got that fixed. As for pressure, it's usually a bad cap, that's what hold and controls pressure in the cooling system.

 

[BlackWorksInc]

They're not supposed to be hard as a rock, firm and hard to squeeze. Sounds like you may have a bad cap going on there. That could also contribute to the temperature variance if the fluid is boiling over into the reservoir and not being sucked back into the cooling system properly.

 

[ghs215]

By golly! I think that was it

Put a new cap on and the pressure came back, hoses are firm again

The pic below is not mine, but it looks the same. What is the purpose of those 2 disks at the bottom? On my old cap, they dangle pretty free, on the new cap, they dont move much. So is this why its bad?