engine temp. veries by about 30 degrees.

Hi,
I have a 1996 Dually Crew Cab with a 7.4 V8. The temp seams to be running high but doesn't over heat. It runs between about 200 to 230 degrees or a little higher if I'm sitting still. What is the normal running temp. and what do you think I need to do. The fluid level was a little low and added about a quart. When I stepped on the gas I did hear some noise in the heater under the passanger side floor. Can you give me some help?

Thanks,

I think you need a new thermostat...My 90 1500 and 02 2500hd both stay around 190-195...
Does the noise sound like water running through it?

Sounds like you have an air lock in the cooling system.