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Q: Car overheating

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I turn on the car , go about 3-4 mins into the road at 40mph average and the car is at it's normal temp. After two stops and I'm at another stoplight, the temp gauge goes up to the middle line and a little past it, but once I take off and about 2 mins into the road again it's at normal speed. I have it on parked and let's say about 5 mins into P mode it's starts going up slightly, little less than the 3 line up. I normally before had put antifreeze for two days straight and it worked fine until like two days ago when what I described started happening. I replaced the Radiator Fan, Cooling Fan Replays (Both), Radiator Cap, Flushed it, and changed the thermostat when I got the car at 222,000 miles. I notice the fan goes on at low speed without ac being on, but when it does start going up past the middle line , I cannot hear the high speed go on. I also check the coolant level thru the radiator cap and there isn't any you could see, until I turn on the car, that's when it starts going up

My car has 230000 miles.

Overheating can be caused by a number of things such as low coolant levels, a faulty thermostat, a clogged radiator or a failing coolant fan switch. As you may know the coolant fan switch helps to maintain the proper coolant temperature by turning on and off at specific temperature thresholds. When this switch is not working properly, this can cause the fans to come on intermittently, all the time or sometimes not at all. When this happens you will notice a temperature spike and drop occasionally as the fan comes on and off. When your thermostat is not working properly or is stuck closed, this will not allow the coolant to properly circulate through the engine, which may cause the engine temperature to fluctuate erratically or in some cases just remain hot. You may also have a water pump that is beginning to fail. Water pumps often times will begin to produce a bit of a whining sound when they are starting to fail. A common problem also associated with this is the water pump may begin to leak around the water pump shaft due to the seal being damaged. In addition to leaking around the pump, you may have a leak elsewhere in the cooling system coming from one of the hoses going to or from the radiator. Lastly, you may have a failing cylinder head gasket allowing coolant to leak from the water passages into the cylinders resulting in the coolant being burnt in the combustion chamber with the fuel. If this is the case, you may also notice a bit of white smoke coming from your exhaust which is a product of the coolant being turned into a steam like vapor. I would suggest having an expert from Your Mechanic come to your home to diagnose your cooling system.

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