Gents,

I have a couple of strange issues with the coolant with my 97 F350 4x4 Crew Cab 460, Auto I need some help with.

First, I am getting the sound of water running/sloshing around in/through the heater core area right after I either start the truck or after it sits idling for a few minutes. No leaks in the heater core, just the annoying sound. Any ideas what might cause this?

Secondly, this afternoon I started the truck and let it idle for about 15 minutes to defrost the windows. I have never had any coolant leaks before, but it was definately leaking when I went out to get in the truck. The temperature showed to be right where it was supposed to be, at operating temp. The leak(s) stopped as soon as I drove off and the thing didn't leak at all after I parked it and let it idle a while. The only other odd thing I have noticed is that, occasionally, when the truck is cold and I take off driving, the temperature gauge will climb almost to the top of the normal range before quickly dropping back to center of normal (which is presumably due to thermostat kicking open and possibly sticking a little).

Could any or all of this be caused by a bad/sticking thermostat?

Thanks for any help you can provide!

 

The temps climbing then falling back down would be a thermostat issue.

The sloshing sound in the heater core just means that air is trapped in the core, and as coolant is pumped in, the air moves around while the coolant bubbles through.

If you're familar with houses that have baseboard hot water heaters (or hot water radiators), you get this all the time. It's just air.

Since you have a leak, that's a good place for unwanted air to get in.