Txwelder

When I first start my 96 2500 4x4 auto, under light acceleration, I hear a "gurgling" sound from the pasenger side of the dash. I have heard this could be a thermostat problem and that could be expensive. I have also heard that I may just need to flush and re-fill my cooling system because it may be low. When the truck gets up to temp, I can watch the temp guage fluctuate like the stat is opening. Any Ideas?

infidel

Mine does it too. I don't worry about it, figure it's just air passing though the heater core.

spots

Shouldn't have air in the heater core. Or anywhere else in the cooling system. The fluctuations you see on the gage is usually the air pockets going by the sensor. If the tstat is working properly the needle should stay pretty steady. Is the coolant level full in the overflow bottle??

Cummin01

I have a 96 2500 2x4 with the 360. Mine also just starting doing that at about 74K miles. I drained & refilled the system, still does it. I am open for suggestions also.

DZLPWR

Yea, my truck does it as well at start-up. Sounds like small air bubbles flowing through a small hole in the core??

SmokinDodge12V

Ive heard that sound in many trucks and my 97 also did it I dont think its a big deal just coolant passing through heater core.

Txwelder

No my overflow bottle has a brown sludge down in the bottom and I checked my fluid level this afternoon and I cant even see the coolant in the radiator. I know it needs to be flushed and re-filled. I just hope the tstat is not gone.

yrusoslow2

My t-stat fluctuates all the time. Will go from 160 to 190 all the time. I have been told from many people that this is normal. I have even changed to the updated t-stat and it still does the same thing. I have driven the truck now for 65,000 miles like this and no problems yet.
Justin

kandgo

Hey txwelder,I would recommend to keep up on the cooling system, the heater cores in these trucks are a real bear of a job and if not done by yourself it costs upwards of $650 and more,keep it clean and mixed correctly with distilled. Thermostat fluctuation is normal and am glad to here in relation of saving some money that the new updated one does it too, thanks yrsoslow for the post about the new one as I was tempted to try one ..... Goodluck,,, Rick

Txwelder

Thanks for the info. Is there any preferred brand or type of coolant to use or should I just go with a good name brand coolant? 50/50 mix? It never gets below 40 here but it sure gets up to 110+!

Cummin01

I have never heard of using distilled water with your anti-freeze, although it sounds very logical. Any body have experience with it?

infidel

Distilled is the only way to go if you have poor or questionable water. We've all seen the white deposits that build up on coffee pots, who wants that in the their radiator?
Some water, especially from wells can also contain other chemicals that are incompatible with anti-freeze and are best left out of the cooling system.

redramnc

The harder the water in the well the worse it is for the cooling system. Use the pre-mixed stuff - it may be a little more pricey but it will keep the mineral deposits out of the system.

ten8fiftyone

Air bubbles causing the sound seems to make sense. After all, the cooling system operates under pressure, not vaccum. And even a vaccum isn't completely void of air. Even if the cooling system had an in-line microbubble resorber (spirovent) I would think you would still have issues because of the open overflow tank? But a 30 degree fluctuation in the tstat readout during normal operation seems odd to me. Then again, this is my first diesel truck, so maybe it isn't? I know with my gassers, if the cooling system was sound, I'd cast a suspicious eye on the tstat sending unit, wiring and gauge.

infidel

The temp fluctuations are the result of a large radiator and are harmless and normal. If you had an oil temp gauge or measured the temp of the metal block you will not see the fluctuations, the temps are very stable except the coolant.