Question about 1998 Mercury Mountaineer

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Overheating. I have a 98 Mercury Mountaineer. Tonight, the check engine light came on and I checked the heat gauge, and it was hot. I pulled over right away to let it cool. I checked to see if there was coolant in the reservoir, which there was. Next I checked the bottom radiator hose which was lukewarm. I next checked the upper radiator hose which was hot. The hose that goes to the thermostat , to the water pump was also hot. There was no notice of water on the ground, or from the pump itself as when they are ready to go, they seep anti freeze. I drove it home, and the heat gauge was a little above half way, and going up. I didn't have far to go, so it was okay to go the last half mile to home. I let it set at home for about an hour and then went out with a glove and took the cap off. There was no pressure on the radiator, so no fluid came out, but the radiator was full. I checked the heat gauge again and it was still at half way. The fan and the pulley also ran so I don't think the fan is a problem. I just checked the heat gauge now, and it is just above the C. What could be the problem? Is it the pump, or maybe a stuck thermostat? Thanks.

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Cover the radiator front, leave the cap open, start the engine for 20 minute or more, wait until the engine gets hot, check the coolant ,see if it is circulated, if it's not, chenge the thermostat first and then check the water pump.

Posted on Jul 10, 2008

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You mentioned that the cooling system had no pressure when you removed the radiator cap. Somewhere the system is loosing pressure. Have your cooling system pressure tested. Have it pumped up to 20psi and watch for any water coming out somewhere. By the way the lower hose and the upper hose are 2 different temps., this suggests the thermostat could very well be stuck. Take a peek at the under side of the water pump with a flashlight. If you see a trail from the weep hole, there is your problem, a water pump going bad.

Posted on Jul 10, 2008


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