I have a 92 Ford Taurus that runs warm, can overheat, especially in city driving. When driving at faster speeds with less stopping does not give any trouble. The radiator is full. I tried putting a new thermostat in and it overheat just the same. I took it out and it would run warm but not overheat. I flushed out the tranny. There are not leaks. Seems like water will come out to easy from the radiator cap. Thinking maybe it is blocked up some inside the engine.
Can a water pump be kicking in and out at lower RPM’s
Is the cooling fan coming on?
Since it appears to be fine at higher speeds have you checked the radiator fan operation?
The fan should cycle on when the engine temp calls for it and it should run whenever the A/C compressor is engaged.
I would also check for the head gasket. My 1998 Taurus did the same thing at first, then got to the point where I couldn’t drive more than 10 miles (my commute to work) before adding water
If your water pump vanes are eroded, the water pump won’t pump enough water at low RPM’s to cool the engine. If you verify that the electric cooling fan is turning on, the next suspect would be the water pump.
“I would also check for the head gasket”
That is why I asked if it was a 3.8 liter V6
I have not driven it much in last 10 years. I believe it is a 3.0 V6. I will check out to see if the fan is kicking in. It did sit for almost 10 years with little driving or running. Water pump vanes could be a problem I suppose. I find it strange that it runs cooler without the thermostat. It also seems to like to overflow to easy from the radiator cap. As it run it will continue to overflow with the cap off a little at a time at a idle. I thought maybe this was a sign of some kind of block up. I did drain the radiator and flush it. I got a bottle of that flush stuff also. I plan to try that also.
I was thinking I may have put some of the radiator stop leak in many years ago. Over 10 years ago for sure. Could this over the years be causing some blockage? I did drive the car in early summer and never overheated at all then. If my memory serves me correct, back around 2004 or so it may have been running a little warm then when I drove it once to New York city, when I was in the city. I believe that at that time I put on the heater, this was in summer, and it kept the temp at a reasonable temp until I got to where I was going.
Yes, radiator stop leak may have clogged the radiator and reduced cooling efficiency at low speeds. You could also have a head gasket leak since you mentioned coolant overflow from the radiator. That can be caused by exhaust gas leaking through the head gasket and making the coolant overflow. With the radiator cap off at idle, check for bubbles in the radiator neck. If you see bubbles, that indicates a head gasket leak.
Make sure the fan is operating first. This era of Ford used a single module that controls fuel pump operation, A/C operation, and cooling fan operation. There were normally referred to as ICRM or CCRM modules (Integrated Controller Relay Module or Constant Control Relay Modules) but had a name change depending upon the year. Basically it was a low tech “box o’relays…”.
The above items consume a lot of electrical current and at times a poor connection would develop at the ICRM/CCRM connector because of this. The usual suspect was erratic or no cooling fan operation. Sometimes it was curable by loosening the bolt that holds the connector on, unplugging it, and then plugging it back in.
I’m not saying that the ICRM/CCRM or connector is the cause of a problem; only that it’ a possibility IF the cooling fan is inoperative.
The 3.0 is a very good engine and not prone to head gasket problems and personally, I always like to think a problem is comparatively minor instead of suspecting the worst.
Some evening after the engine has cooled you might loosen the radiator cap to relieve any pressure that exists. Retighten the cap and go to bed.
The next morning raise the hood, start the engine, allow it to run for 20ish or so seconds and then hurriedly loosen the radiator cap. If you hear a noticeable hiss there may be a head gasket fault. If you hear nothing or very little then odds are the head gaskets are fine.
That’s backyard testing at its finest…
Car Talk did nothing for my Toyota Supra problem, but it sure helped here. It is the fan. Such a simple thing and I never thought of it. It was not kicking in. I took it off and tested it and found out the problem was that the motor was moved just a bit making the fan to be hitting the sides and causing it not to turn. The fan motor and fan itself is good. I have repaired it and it now works fine. Thanks people. Yes you are right ok4450 very minor indeed.
Congrats on getting your Taurus back in good running condition. If you haven’t done so already, be sure to put the new thermostat back in btw. And make a note where the dash coolant temp gauge needle resides for both city and highway driving, for future reference.
If you haven’t changed out the radiator cap in some time, put that on your list of things to do, when its convenient.
“I find it strange that it runs cooler without the thermostat.”
Understand that the T-stat’s function is NOT to help the engine dissipate heat by allowing the coolant to pass, the T-stat’s function is to allow the engine to reach operating temperature BEFORE allowing the coolant to pass. An engine will always run cooler without the T-stat to allow it to warm up. But that ain’t a good thing. Engines operating at proper operating temp run much cleaner, better, and more efficiently.
It is a 92 that has seen better days. Running cleaner and more efficiently has not been a high concern for years. I am lucky if I put 200 miles on this car per year. All I want for this car at this point in its life to make it from point A to B and back to A. Preferably without it breaking down on the way. But I agree with you all the same. Thanks.