1996 Ford Ranger 4.0 Overheating

overheated

Ford Ranger 4.0 1996 Continues to overheat even after flushing system, replacing thermostat, replacing EGR valve. Not gaining any oil or losing any water don't think it's a head problem.

Mr_Shiftright

Flushing usually doesn't work and so you may still have a clogged radiator. Do not assume a flush has eliminated this possibility.

Also, what is the basis for presuming no head damage? Have you done a compression test and/or a cooling system pressure test? You can have a head problem without losing water, as a cracked head would cause exhaust gases to heat up the water just like a tea kettle.

If the overheating is FAST, you may indeed have a head gasket problem. If it only happens in traffic, maybe a cooling fan not working? If slowly at highway speed, radiator is likely.

Also, are you really overheating. Have you tested the water temp (CAREFULLY) with a thermometer (mechanic's thermo, special long, big type).

jgmilberg

Is it actually overheating, or could it be a bad sensor for the gauge. What do you consider overheating? Most engines run between 195, and 210 degrees F.

It could be a bad water pump, I have had to replace 3 water pumps on different Ranger trucks, the impeller was just sitting there as the shaft spun inside it. I never saw that before, but it did fix the overheating problems. Another thing to try while replacing a water pump, if the car/truck has a lot of miles on it is the fan clutch. It is the thing that the fan blades bolt to, then gets bolted to the water pump. They do go bad, most of the time it just doesn't let the fan engage when it needs to, leading to overheating in traffic, but sometimes it can knock the fan off balance and kill the water pump bearing.

Look at the radiator, if the tubes inside are crusty, it's probably time to get a new one. Another way to look at it is to look at the bottom of the radiator, inside the fan shroud, with the engine OFF of course. If it looks green and nasty, get a new radiator.

One other thing that usually gets overlooked is to unbolt the radiator, and clean between the radiator and the A/C condenser. Depending on the area you live it may be all plugged preventing air from flowing through the radiator.

bmaige

We had a Toyota Corolla at one time that started running warmer than it had when we got it, but never ran hot. I changed the thermostat and nothing changed. Since it was just running higher in the normal range I didn't worry about it. After a lot more miles the water pump had to be replaced and that dropped the temperature back into the same range it ran in before I noticed the temperature rise. I can only suspect the impellers or housing around them had eroded to the point they weren't moving water as efficiently as the new one.

If yours is running hot, which I assume means into the danger zone, I would want to consider things logically with the least expensive first.

1. How old is the radiator cap--if new is it the proper one for your vehicle? I have a Ford 5000 diesel tractor that ran hot and kept losing coolant. I could see it leaking but couldn't see where it was coming from. I finally replaced the radiator cap and it stopped my problem for $7.00.

2. Is the coolant proportioned properly, in other words the right amount of "antifreeze to water?"

3. As has been suggested already, is there any radiator blockage picked up in driving (bugs, plastic sheet, grass, mud, blocked AC condenser coils, etc.)?

4. Is the thermostat all right? Even a new one may not function properly or could be installed wrong. Test it by leaving it out entirely, driving the truck, and see what the temp does.

5. Are the radiator hoses collapsing and restricting water flow?