2000 Contour Overheating Problems

[flynnd27]

2000 Ford Contour keeps over heating. It started with my water pump going out and I immediately stopped the car and towed it to my shop to replace the pump. Since then the engine gets hot under any load beyond driving on the freeway.

I have:
Flushed the system
Replaced the thermostat
Replaced the water pump
Bleed the system of air

The temperature gage reads just below middle on the free way when I am on flat ground. It will remain at this temperature even with A/C on full. In town or going up hills at any speed the temperature will clime to the top of the gage very quickly.

There is no fluid loss or fluid in the oil so it does not seem reasonable that the head gasket has broken.

The Fan works properly

The pressure builds of so high in the cooling system that the expansion tank actually looks like its about ready to burst each time the car's heat gets high.

The most recent work was changing the thermostat and that has made the biggest difference so far but the car still gets very hot on hills and around town with the A/C on.

I am out of ideas. Any legitimate thoughts would be appreciated.

[jmewing]

Just went through similar problems with my daughter's 1994 Mazda Protege with automatic transmission and 1.8 litre dohc engine. We constructed a jumper wire [through a 10 amp fuze] and plugged it into the main paddles under the fan motor relay, in the fuze box. Radiator cooling fan came on, so we knew the cooling fan wasn't the problem. We then installed a new relay and presto: problem solved ($14.99 part from AutoZone).

If you are getting hot coolant blowing back into the expansion tank, it is possible that you have blown a head gasket. Is the liquid in the catch tank green like antifreeze, or is it now frothy and cream-colored? Does the liquid in the catch tank smell like antifreeze, or does it now smell kinda like gasoline or exhause fumes? If it is frothy and cream-colored and smells like something other than antifreeze, the head gasket may be the problem. There are a couple of compression tests you can run. First, and simplest, is to get a pair of them big plastic pliers, and -- with the engine running -- pull one spark plug wire at time, paying attention to how much of an RPM drop you get when you pull the wire off the spark plug. If you get no RPM drop, or less of an RPM drop than on the other three cylinders, you could be in the neighborhood of where the head gasket is blown. A more sophisticated test would be with a compression guage, which you mey be able to borrow from an auto parts store. For this test, be sure to first remove the high tension wire which runs from the coil to the distributor. Next, remove all four spark plugs. You can then screw your compression gague into each spark plug hole, one at a time, then crank the engine, repeat for next cylinder, etc. When finished, compare psi readings for all four holes. If one of them is like non-existant or way lower than the other three, then the head gasket could be blown in the neighborhood of this cylinder. I hope a blown head gasket is not your problem, because if it is, you will have to pull the head, take it to a machine shop where they can check for cracks (dye and/or magnaflux), and check to see if the head is now warped. In any event, you would probably want to have them mill the head, to make sure it is perfectly flat, else more blown head gaskets. I hope this is not your problem, but when you get coolant blowing out of your expansion tank, it generally means that pressure from a piston is the reason, and the cause is a blown head gasket. Because it is somewhat expensive to fix, don't rely on what you've just read. Get a second opinion. And a third and a fourth.

PS: My 1998 Contour LX runs just fine, and its been hotter than hell in Houston lately.

[flynnd27]

The fluid in the expansion tank is fine and there is no antifreeze in the oil either. The easiest test for blown head gasket is a chemical block test. The head gasket seems to be fine. The fan works fine and the car does great on the open freeway with the a/c on hi but the car quickly overheats when going up a hill or putting additional load on the engine. It almost acts like there are air bubble in the system but I have bleed the system and it appears to be clean now.

Also, the transmission seems to be shifting strangely; going up hills I have noticed that the transmission wants to shift in to higher gears instead of lower gears. I wonder if this is overworking the engine and causing the problem.