How do you diagnose over-heating problems on a Taurus - Sable?

Answer 1

Copied from the "Related Question" below, written by DustedDisgusted:

• Is the coolant at the proper levels?

  Is the coolant 'fresh' - still has most of the original color (green, yellow)

  Note: One symptom of a leaking head gasket is "milky" looking coolant ?

• Next, let the engine warm up, feel the top radiator house, if it's not hot/really warm...

  * Thermostat may have stuck closed

  * Cooling system blockage - flush it

  * Water pump -

  * Metal water pump impellers are prone to rusting away if the coolant hasn't been changed often enough.

  * Plastic/nylon impellers tend to wear away, or even break (ala original Ford Contours)

• If that's ok, let the engine run and make sure the cooling fan comes on, if it doesn't, check: fan fuse; the temperature sender; or the fan may have failed.

  Turn on the a/c and the fan should come on immediately (you could possibly have a bad pressure switch in the a/c system that would keep the fan from coming on, but that's unlikely)

• Next turn off the engine and feel the lower radiator hose, it should be very warm, if not you possible have a flow issue, either the water pump or a clogged radiator core.

  The best way to check for lack of flow is to remove the radiator hoses and run water through it, comparing inlet volume/time to outlet volume/time.

• If these are all good, could be a head gasket.

  One test is to get a smog test station to check for HC's (hydro-carbons) in the cooling system by removing some coolant and sticking the "sniffer" in the radiator neck while in manual gas reading mode. there should be no hc's present. any reading warrants removing the heads for further diagnosis.

Other ideas?

There are many possible causes for over heating.

1. Thermostat sticking closed.
2. Low coolant level, causes are (coolant leak internally or externally, for internal leak check for antifreeze in the oil, it will be cloudy or look like a milkshake.
3. Water pump failure.
4. Blown head gasket,signs are ( oil in antifreeze, air bubbles in coolant recovery tank, caution hot coolant can spray out without warning)and or white smoke (steam) out the exhaust, and or low compression in one or more cylinders
5. Engine cooling fan malfunction (manifests when vehicle at a stop and running)
6. Plugged radiator (either internally or externally)
7. Collapsed radiator hose
8. Incorrect or seized radiator cap

Does the engine cooling fan come on at 230 degrees and turn off at 190 degrees? You could have a bad cooling fan, relay or sensor problem. If all of these check out you need to check for leaks and repair them. Also a stuck thermostat can be the bad apple.

There was a recall on this car for problems with the cooling system, so the first thing to do is check to see if the recall was performed. Also, there was a TSB, number 01-11-6 dated 06/11/01 addressing this problem. It involved, among a number of other things, replacing the water pump with a modified water pump. The new water pump is part number 1F1Z-8501-AA.In addition, I would replace the serpentine belt with Ford part number F7PZ-8620-AB since there was a problem with the serpentine belt slipping.

If, after all this is done and it still overheats, the freeze plugs may have to come

out to inspect the block water passages for obstructions.

Engine overheats when a car or truck overheats idling, in town, on the highway, while towing, etc. it is important to find out the reason to prevent engine damage.

First, with the engine cold, make sure the radiator is full of coolant; if it is low, fill it and keep the radiator cap off while the engine idles to insure all air is bled out of the system.

Check the coolant level daily; if the coolant goes down without visible leaks, it may be a head gasket starting to leak which will also cause the heater to blow cold air due to the lack of available coolant.

If the coolant stays full, but the car continues to overheat, the next step is to replace the thermostat in the engine and flush the cooling system if that has not been done over the last few years.Buy a thermostat at a parts store and a PRESTONE flush kit which has excellent directions on the package.

After completing these steps and the vehicle still overheats, have your cooling fan sensor/switch ( if equipped)checked out to insure it is coming on.

Water pumps are seldom the cause as they are mechanical and will continue to work until their bearings give out.

Finally, the radiator itself is often the problem as it tends to build up corrosion internally which prevents it from transferring engine heat to the coolant. Remove it and have it 're-cored'.

One of these steps will solve the problem.

In addition to this comprehensive round-up, I would suggest that water pumps can fail without the bearings going out. The impeller can wear and/or break loose from the shaft.

See "Related Questions" below for more

You should service the cooling system. Flush the radiator, replace the thermostat, install a 50/50 mix of new coolant, bleed the system, verify that the cooling fan/fans are working properly.

Thermostat stuck closed or the water pump has plastic impeller that broke. When my 97 sable water pump failed as above, it would be okay idling, but overheat when revved up or driven any.

check the coolant temp sensor, and make sure the fans are going if they are electric.The thermostat could be the problem. If the thermostat is not functioning, which happened to me on a long distance trip, the temp gauge in the car will not show any increase in temp. Sooner or later, like when you stop at Burger King, you will notice your car is overheating, coolant is pouring out onto the pavement, you are astounded since your temp gauge shows the engine temp is normal. What happens when the thermostat malfunctions is that it won't open up, allowing the cooling fluid to enter the engine, thus causing overheating. Good news is the thermostat is a cheap part, you can get it replaced for an hour's work of a mechanic, or if you are handy, you can replace it yourself. Check the rubber hose that goes to the engine from the radiator to see if it needs to be replaced, replace it at the same time (replace it if its cracking or very old).In my case, I was in a location that I could not get a new thermostat, so the mechanic took out the faulty one, urging me to get a new one soon and have it installed. I did that, and all seems to be well. The deal is that the thermostat keeps the engine temp in synch with all the electronics. You can drive it without the thermostat for a while, which just means that the cooling fluid goes right into the engine immediately instead of being controlled by the little thermostat (basically a gate that opens when a certain temp is reached). However for optimum performance, you should have the thermostat on there. But in an emergency, ie no part available, you can run without it.

Check the cooling system. Does it have enough antifreeze? Is it leaking any? If so, check the hoses and radiator. If that's okay, it could very well be the thermostat. If it gets stuck closed no coolant gets circulates. It's an easy fix. Just don't buy one from an autoparts store... buy a motocraft (ford) part. The aftermarket ones don't really fit like they should.

Make certain that the water pump is working. Replace your thermostat, it's probably stuck closed. If you follow the upper radiator hose out of the radiator, it will end in the thermostat housing. Take it off and you will find the thermostat inside. Note the orientation of the thermostat before you take it out so you know which direction to put the new on in.-Jesse