Overheating no noticeable signs that radiator is leaking, no fluid around the water pump to indicate that it may be going bad, temp gauge hits 180 then the fan kicks in...do you think the thermostat may be bad/

If you are not losing coolant and the temp gauge reads normal, it sounds like everything is OK. Many parts of an engine will be too hot to touch.

If still wanting to make sure, you could renew the temperature sensor unit as well.
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Look at the area where you park. Is there any fluid under the car that is not oily but rather is slick and has a sweet smell - yes, you wil have to stick your finger in it to see. If you find this type of fluid, you have a leak from somewhere in the engine compartment. Judge by the amount of fluid whether this is a major and potential calamity. (Lots of antifreeze could mean a bad hose or a bad water pump.)

Once you've checked for leaks, check the plastic reservoir that holds the radiator coolant overflow - is there anything in it? If you found alot of fluid on the ground, odds are that the reservoir will be low. If it is much below the fill line, add some water and coolant (50/50 mix) until it is back to the fill line.and check it for awhile to see if it needs more after you have driven for a bit (keep the coolant with you in the car just in case.) When the engine is cold, and as you are checking the reservoir, remove the radiator cap by pushing down on it a bit and turning it in the direction shown on the cap itself. Look into the radiator with a flashlight to see where the fluid level is. If it is more than 2 inches from the top, add a bit of coolant/water but not up to the top. Replace the cap firmly and add coolant/water to the reservoir cold level mark.
If that all looks fine, you may have a bad water pump, a plugged radiator, a week cooling fan or a bad thermostat.

Good luck.

Sorry to say you probably have engine troubles.
A leaking head gasket will drink the coolant and cause the bubbles to form.
A mechanic can check for leaks by pressurizing the cooling system and also checking for exhaust gas in the radiator.

It could be the thermostat. It could also be the water pump, radiator, cooling fan or a hundred other things. The first thing you need to do is make sure the engine is cool, then take the radiator cap off and check the fluid level. Check the overflow container as well to see if it has the proper level of fluid in it. If you can see the fluid in the radiator near the top then it could very well be a siezed thermostat. If you can't see the fluid level in the radiator, then fill it and the overflow container to the proper level and start the engine with the radiator cap OFF. Look for any obvious leaks under the car and around the engine and radiator, but keep your eye on the temp gauge. Water pumps have a built in warning device called a "weep hole" which will leak water out to let you know that it's time to replace them. If the radiator appears full and the cooling fan comes on, and the engine still overheats, then it is definately the thermostat. A rapidly overheating engine would constitute no water in the engine block itself which is very dangerous for your engine. If the engine remains too hot for too long, you could end up with much more serious problems.

Your sending unit is definately bad running at 180 - 210 is perfectly fine and it is not overheating at all.Replace it and your problems will be solved. But make sure you are using your lazer temp gauge at the same point as your temp sending unit.If you are then it is your sending unit if not you may have air in the system at the point of the sending unit and this will cause your problem as well.

Last time I had this problem I had a cracked head. With the cap off the radiator, run the engine at idle to operating temperature. When your looking in the radiator you should see the water circulating if the water pump is working. When you say the motor is over heating, if you have fluid coming out of the over flow hose then yes you are most likely overheating, if you are just seeing the gauge indicate you are over heating you may just have a bad engine temp sensor.

you have 4 water lines, they are 2 radiator hoses (top and bottom) the bottom one runs from the lower part of the radiator to the water pump, the top radiator hose runs from the upper part of the radiator to the thermostat housing

2 heater hoses, they go from the water pump to the firewall.

if you know which one has a hole then you should take the van to a parts store (if you can safely drive it that far) and show them, they can get the right one for you... and sometimes you can talk someone into putting it on for you.

as for the fluctuating gauges you probably need new sending units for the temp gauge and fuel gauge

Chevy is known to have manifold intake gasket weakness- it may have to be replaced (~$500). That would probably cause slow overheating. You may be leaking coolant through that leak.
Also, the water pump (much cheaper) can break, causing rapid overheating.
If you went to an honest mechanic they should be able to diagnose it using a thermometer.
If there is no smoke from the engine, don't let them convince you it is the engine...they tried that on me.

You don't give much to work with. Many things can cause this. Is there a fluid leak? Does the temp gauge jump suddenly to show it is overheating? If so, it is probably the thermostat sticking and needing to be replaced. If not that, could be water pump (should be leaking) or a bad radiator.

Hello Ranger Joe, eight months and two radiators is very uncommon. Question, Have you visually confirmed the leak in the radiators or is the leak near the hose connections? Replacing the radiator, cap, water pump, & the thermostat leaves only two others, the hoses and the engine block/heads. Far fitched will be something or somebody poking holes in the radiator.