it may be a defective sending unit or sensor.
Np, because most of your coolant is contained in the engine block. So when you drain your coolant from your radiator, most of the coolant will *remain* in the block.
There's a sensor in the bottom of the coolant expansion tank.
There is coolant in the engine block when the engine is not running. The engine block, heater, hoses and radiator remain full when engine is not running.
The assumption is that you are discussing the radiator fan. Radiator fans run as long as the coolant is above a certain temperature. If the sensor is faulty it could be forcing the coolant fan to remain on even after the temperature has dropped to normal
Certainly. If the engine coolant is flowing freely into the radiator, it will remain quite cool and the coolant that circulates into the heater core will never warm up. The thermostat blocks the coolant from entering into the radiator if the temperature is below the set level on the thermostat. Usually 185, or 195 degrees F. Engines don't run as efficiently at the lower temperature either, so if the thermostat isn't working right, replace it.
A radiator is defective if fluids are leaking out of the radiator or there is a leak of steam. Or, if thecore is blocked, the radiator will remain cold or just slightly warm in places.
The radiator of the car must be filled with water upto the brim, so that the engine will remain cool.
The cooling fan temp sensor detects the coolant is hot and it will remain on until the coolant cools down, usually in a few minutes. Check the coolant reservoir to be sure the coolant is at the proper level. Must be an import.-Normal.
Here are the basics. There are many problems you may run up against (frozen bolts, stubborn or cracked hoses, rusted clamps, etc)that may need to be fixed or replaced before proceeding: SHut off engine, allow to cool completely. Disconnect the cooling fan, remove negative battery terminal connection. Drain radiator by opening draincock and/or removing lower radiator hose, collecting coolant in a drain pan. Do not let it go onto the ground - bad for environment! Open top radiator hose to allow remainder of coolant to flow out. A few quarts of coolant will remain in the engine block. You will want to totally flush and refill AFTER replacing the radiator to get all the crud out of the system. Unbolt radiator and disconnect any other items still attached (transmission cooler, temp sensor wires, etc.). Remove radiator and replace with new, reattaching all items removed from old radiator. Inspect other items and possibly replace suspects. Reattach hoses and make sure the clamps are tightened without pinching hoses excessively. Do a flush job with water/radiator flush, making sure the water runs clear out the draincock. Instructions for flushing the cooling system are usually printed on the radiator flush bottle. Be sure the heater is on and the engine warms up completely to open the thermostat. SHut off engine and drain as much water as will leave. Fill with 50% coolant mix (Dexcool or equivalent). Estimate water remaining in the engine and add 100% coolant to balance. COmplete fill with 50% mix. Remove air by running engine until warmed with the radiator cap off, adding coolant mix along the way. IF the fluid rises quickly it may indicate a bad head gasket.
When you mentioned you had checked for correct coolant levels what do you mean or think is correct? If you are filling the coolant level to the top of the radiator neck when the engine is cold (then you are overfiling the radiator - keep in mind your vehicle does not have a coolant recovery tank), once the engine heats up the coolant will expand and if the radiator was filled to the top of the radiator the expanding coolant will overcome the cap pressure (listed in psi on the top of the cap)I would recommend leaving the coolant level down approximately 1 inch from the overflow hose. If you are not overfilling the coolant level then it could be caused by a defective radiator cap. The pressure rating on the cap can be used to test the relief valve by using a radaitor/cap pressure tester (your local parts store more than likey has one that is available for customer use. Bottom line is a typical radiator should have a rating of 14 or 15 pounds. When they test the cap it should hold whatever the rating is on the cap. You will notice when the cap is tested it will quickly go t the rated pressure and slightly above then it should release the excess and remain at the prescibed poundage rating on the cap. If it does not hold replace the radiator cap. When you replace the cap I highly recmmend that you order one from your local GM dealer, due to the mettaurgy of the radiator (usually aluminum) if you put on a normal radiator cap you may end up with a problem with electrolysis which could cause pin holes in your radiator, heater core and even possibly in heavier metal parts. Again I would highly recommend that you replace it with OEM parts. Do not rely on the individual behind the counter at a non dealer parts house. He or she may not have the technical training and it couldcost you a $1,000.00 radiator. As I indicated earlier it is important to insure the radiator cap is working properly since 1 # of pressure increases the boiling point of water 3 degrees (at sea level). For example a 15 # radiator cap X 3 degrees would equate to raising the boiling point 45 degrees (3 X 15 = 45), add the 45 degrees to 212 degrees (the boiling point of water) and you end up with a boiling point of 257 degrees. When a car has a 190 degree thermostat it is designed to keep the car at approx 190 degrees as long as the car is running which will allow the water pump to circulate the coolant through the radiator which will allow the heat to disipate from the cooling system. When you turn an engine off the coolant temperature will raise 20 to 50 degrees, if it is already at 1190 degrees when running and it raises 30 degrees the temp of the water now exceeds the boiling point of water at sea level (if the radiator cap is not working the pressure would be the same as atmosheric presure) in other words the temp would be 190 + 30 = 220 degrees or 8 degrees above boiling and the coolant will boil and overflow. To diagnose your problem determine the proper coolant level, insure the cap holds the proper pressure and if there are stil problems you may have a radiator of coolant circulation problem with the engine. I did not discuss the fact that properly mixed oolant will also raise the boiling point of the coolant but the mi is more than likely not the issue unless you have pure anti-freeze. Good Luck Rich email@example.com