Chevy 2000,Venture Low Coolant lights up while driving. Twice over heated Red light, temp gauge went all the way up. I pull over and saw the coolant is not boiling hot but coolant over flowing.No steam comming and coolant is cold. What shall i do .I am worried to travel far. I just bought the van from chevy dealer.

You are low on coolant. There is air in the coolant system. This is the reason it jumps high with no heat.

New thermostat, installed, saw, new coolant made a little mess filling reservoir, (normal) checked fan fuse for some reason, and condenser fan fuse (xxx ?:), and temp guage, is slightly lower on gauge (than normal?) (disconnected xxxx? quit? a bit? to get to thermosta?.t no dash warning lights have a feeling I popped a relay.

Answer:

ok, you did a coolant service with STAT,

and it failed.

tell us what works right and wrong, symptoms only.

over heating? parked, (fan never comes on)? as it hits 225F?

under heating? ( fan stuck on , up North can cause huge cold engine)

dash gauge stuck low. (thermostat wrong heat range 180f is best. see FSM for spec. on this temp. spec..

Dash guage varies.? oddly (air in system)?

Dash gauge too high.? (Stat put in upside-down or bleed hole (jiggle) not UP side. higher side of mount , trapping air.)

Does something wrong happen only driving?

leaks?

does cap on rad hold 12-14psi pressure, hot.?

if car has fan belts, are they tight? (for sure water pump does)

Hi,

The overheating and lack of cabin heat both point to a failed engine thermostat which would be stuck closed. At the warm up stage, the coolant stays in the engine block to bring the engine to efficient operating temperature, then it opens and circulates the coolant through the radiator and heat core. If the thermostat is stuck closed, the engine will overheat, and coolant will never reach the heater core, and you will not get cabin heat.

Blinking oil light at idle which goes away during driving could be a low oil level, but may also be a drop in oil pressue. You could have a clogged oil fliter (at best) pickup tube, or a failing oil pump.

You are describing a slow coolant leak and the resultant no heat and blockoverheating symptoms. The no heat is because there is insufficient coolant to cycle through the heater core, and the chuggin you describe is the engine indicating serious overheating.
With engine cold, you must add water--not anti-freeze--to the radiator itself, until it reaches the top of the radiator, then start the engine. If you do not have a radiator cap in addition to the overflow bottle (some vehicles don't), you must still add water to the radiator, even if you have to bypass the overflow bottle hose to do it. Add water until no more will go into the radiator. Start engine, let idle until operating temperature is reached. Thermostat should open and a good bit of the water will "sink" into the depth of the radiator. If you have no radiator cap, observe the temperature guage. When it reaches normal operating temp, when the thermostat opens, the temp will drop briefly at first, and you will notice warm air from the heater/defroster.
Once engine is warm and known to be full of water, seal radiator cap and/or system, and let idle for 30 minutes. Use this time to locate the "mystery leak." They can be very hard to find, and some won't leak until after the engine is turned off. During this idle period, observe the vehicle exhaust from the tailpipe as well as looking for actual water leaks: sometimes a bad head gasket can be diagnosed this way; if the exhaust is white and thick like steam, and smells like anit-freeze, you have a more serious problem. It is possible that after the repeated overheating cycles you have endured you may now have both a "mystery leak" and a blown head gasket.
Once leak is located, your next step is to let engine cool completely, drain the water, fix the leak, and then and only then add new antifreeze of the proper rating and ratio recommended by Chevy for your vehicle.
Anytime you drain a cooling system and refill it, it is necessary to check the overflow bottle at least 3 times in the first week after repair to ensure that you have the proper coolant level, and have not either missed another leak or not correctly repaired one. You MUST check it before you drive the vehicle the second time after the first repair attempt because it is normal to need to add more coolant than you added initially after the repair because of air trapped in the cooling system that will only be expelled after the first start/stop heating cycle. If after 1 week of daily normal driving you have only added a little more coolant once, and there are no more problems, you can be very comfortable that you have fixed your car.

well check the coolant level. it sounds like you had a vapor lock and that would cause steam to escape and cause connections to get wet. this may have cause your battery to read dead. if you aren't low on coolant then i would start with the thermostat. that is easy to change and cheap. if you have low coolant then you may have vapor lock. to fix that you need to let the engine cool down and if you have a radiator cap remove it. look inside you should see coolant. if you don't fill up the radiator with coolant. with the cap off start the jeep and turn the heater on. let the engine warm up. watch the temp gauge and keep looking in the radiator. if you don't see coolant keep add it. at times it will bubble and burp this is normal. keep checking the temp gauge. now see if you feel heat coming out of the heater. if your feeling good heat then the system is circulating. (this mean your not in vapor lock anymore) let it keep running and keep adding coolant till it is full in the radiator. once full put the cap back on and fill the coolant tank to the full point. keep running it but keep checking the temp to be on the safe side. if the temp stay steady you should be good. hope this helps. please rate.

On my daughter 2000 beetle with 2.0 engine, the blue thermometer light comes on solid when you first crank it up because the coolant/engine is below operating temp. I have seen the red thermometer blink when the coolant is low.

you never want the temperature guage at the red, at this time usually something major becomes damaged. Check your coolant level, if low inspect hoses, radiator, waterpump for leaks.

Chevy made some weak intake gaskets on 3.1 and 3.4. My guess is that the intake gasket is weak and/or leaking and it is letting pressure out somewhere. At idle maybe the system pressure is to little to push hot coolant into the heater core.

change the thermostat and the temp gauge in the radiator

Sounds like a CPU problem. your radiator may need a good flushing a s well. i would also check the heater core for any unusual problems like seal break or leakage.