Is It OK to drive a car without the thermostat? If yes, for how Long?

I'm assuming that my thermostat sensor or something is not functioning properly. When I drive my car, the top radiator hose is hot but the bottom isn't. My car tends to overheat about an hour of driving it. I change the thermostat but the problem still exist. What could be the problem?Is It OK to drive a car without the thermostat? If yes, for how Long?
I'll just give you the simple answer good for ';most'; vehicles..... yes, it's ok..... but in winter it will take much longer for your heat to work, as you aren't letting the water to heat up long enough to produce heat. without the thermostat, the water/anti-freeze will free flow through your engine and radiator.Is It OK to drive a car without the thermostat? If yes, for how Long?
this is a bad idea. you will definitely see some adverse effects in this situation. the coolant will take quite a while to warm up . this will cause a big change in your fuel economy. it sounds like you have a blockage in the radiator. if the upper hose gets hot (like it should) but the lower end stats cool you either have a blockage or a failed pump. on some of the newer cars you can find an electric water pump this could present a problem in your situation if nothing else is obvious, like stiff steering or a charge lamp that stays on. this would all signify a thrown belt.
Are the radiator fans coming on? If so, you could measure the temp of the upper rad hose with a laser thermometer and see what the actual temp is. maybe your gauge is not reading right.
Could be a huge airlock or blocked rad core.
Again, I wish you'd have included the year make and model of your car. If it has electric fans are they switching on? If so do you have the original radiator? How old is the car? Do you have a silicone filled thermostatic mechanically driven fan hub? Do the blades speed up as the temperature rises? Have you ever used any products along with the antifreeze such as Barr's Leak or ant brand of stop leak? Do you still have plenty of heat coming from the heater?



As a general rule of thumb drain the radiator and flush the system with a Prestone flushing T in the return hose from the heater core. Flush till the water is clear. Drain the radiator of the clear water. Dump two 33.5 oz. plastic bottles of **Prestone Super Radiator Cleaner in the radiator. If it will not all fit. Pull off your coolant recovery tank and clean it out with Wisk and a round bristle brush. Dump the remainder of the cleaner inside the coolant recovery tank. Auto Zone and Advance Auto has this product. Do not substitute with anything else!



This cleaner is unlike the other Prestone product: Prestone Radiator Flush. The instructions say to actually drive a minimum of 200 miles with the cleaner inside the cooling system. At the end of the bare minimum 200 miles flush and drain again till the water is clear.



At this time install a new Stant or AC-Delco thermostat (correct heat range) and a new closed system radiator pressure cap -minimum 13 lb. If this car were mine I'd drive it a week with nothing but pure water and a bottle of NAPA'S cooling system anti-rust so as not to waste expensive antifreeze if the radiator, radiator hoses are collapsed in the center or radiator core is seriously plugged with corrocion, rust or stop leak. If the motor runs within its normal heat zone for a week or two, drain and flush and do your antifreeze thing.



Please be sure you're using the proper type of antifreeze. Buy a couple gallons of 100% antifreeze. When ever you re-fill any cooling system look in your handbook in the specifications page and find the cooling systems capacity. Pour exactly half the capacity first with 100% antifreeze. Make sure the coolant recovery bottle is clean. fill the coolant recovery bottle with any antifreeze you were unable to fill in the radiator. For the first week or two keep the coolant recovery bottle nearly full with water only after half the capacity of the cooling system has been met with 100% antifreeze. The coolant will drop noticeably during the first week or two of driving keep it a minimum of 3/4 filled at all times. The heat cycling of the coolant purges air from the cooling system causing the water leval to drop. This will stop at the end of 100 -200 miles of on and off driving.