Dojman

Plenty of fluctuation here too, both trucks. I've had five of these and every truck I've owned has done that.(Dodge CTD's)

BPonci

Mine used to do the same thing .I took the fitting out and made a restricted fitting.About half the size of the inside dimention.

Txwelder

I flushed and filled the system but still hear the same sounds. Must be too much of a big deal.

albacore

The temp fluctuations are absolutely normal. Cummins states that their engine is designed to run cool, and is meant to be worked hard. As the engine reaches 185 to 190 degrees, the T-stat opens, circulating coolant throught the block, quickly reducing engine temps. Cummins states the fluctuation is perfectly normal. You can actually watch the gauge as the T-stat opens. This is very unlike a gasser, whose needle will pretty much settle on the same spot on the gauge anywhere in the "normal" range of operating temp. The fluctuation on a Cummins is normal. As for the water swishing sound, there is air in your cooling system. That is why you can hear the water swishing in your dash area. Mine does this for a day or two whenever I flush and refill my cooling system. Be sure your radiator is completely full. If topping off a couple of times to purge the air does not work, you may have bigger problems. My dash made this sound when my head gasket was blown last year. The exhaust gasses were being forced past the breech in my head gasket into the cooling system, and were displacing coolant out into the overflow. Try purging it of air first.

95black2615

Mine gurgles like that when the coolant is a little low or has air in it.

HONKEYTRUCK12

My 95 makes that sound also. At 140k I put in a new radiator, water pump, hoses, and had the block flushed. The truck still makes the noise, and the temp. guage's movement back and forth is even more extreme now. My buddy has a 97, he said that there is a part that controls that coolant flow, and that is what makes the sound. My buddy took that part out, and put in a 170 degree t stat. The temp guage now holds like a rock, but it takes 50 miles to get heat out of the heater.

albacore

That isn't good. Things are placed there by the manufacturer for a reason......

diesel96

An idea just came to me....Why not collect the condensate from air-conditioning units, or dehumidifiers? Use the water for radiators, and even to top up batteries. Could even use it for the final rinse when you wash your truck.....no more spots!!!