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Q: Car temperature keeps going up and coolant level drops.

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I recently purchased a coolant reservoir bottle since the old one had a crack and was dripping coolant, i flushed the coolant from the radiator as well. After refilling the coolant, i noted that the car started to misfire, and the temperature is going up. In addition, when the temperature rises, i stop the car and check the coolant level, every time i check after this happens, the coolant level drops a lot, i have to refill. After taking the car to a diagnostic garage, they couldn't find any problem using the diagnostic machine. But after checking the engine oil, they found it to be milky. Please advice what needs to be done, and if i can still fix the car and be using it.

My car has 245000 miles.
My car has an automatic transmission.

Hi there. The milky engine oil is caused when the coolant from the cooling system gets into the engine oil. There are two ways that the coolant can mix with the oil on your vehicle. The first way is through the intake manifold as the gasket may crack causing the coolant to drain into the valley area making the coolant mix with the engine oil. However, the engine will not overheat quickly when this happens. The second way for the coolant to mix with the engine oil is through a burned head gasket. To verify that the head gasket is burned, get a block tester from your local parts store and set up the tool by putting the blue chemical in the tube and putting on the plunger on the end. Then remove the reservoir cap or radiator cap (take precautions of the coolant) and start the engine. Take the tool and place it over the inlet area to the reservoir or radiator. When steam starts to form in the area, use the plunger and suck in the steam into the tool. If there is any hydro carbons (raw unburnt fuel) in the cooling system, then the blue chemical will turn to a yellow or greenish color. If the color changes, the head gasket is burned and needs replaced. If the chemical does not change color, then the head gasket is good and there could be a leak on the intake gasket. I recommend seeking out a professional, such as one from Your Mechanic, to help you diagnose your engine overheating issue.

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