Ford Taurus leaking coolant from cap.

It has an electric fan that cools the radiator. The water pump is belt driven.

It also has a thermostat that regulates water flow, until the engine is warm.

If the radiator cap is old it could also contribute to the problem.

In order of increasing cost, replace in this order:

1. Radiator cap.

2. Radiator fan.

3. Water pump.

No, there was overheating. Steam was forcing out the coolant. If the sensor for the gage is in the radiator and there is little flow there, that would explain the symptoms. The cap is plastic and on top of the overflow tank. It appears to be OK.

As an update, I discovered yesterday that I had not properly filled the overflow, as the car was on a slope in front of the house. I moved it to the driveway and put in more coolant. (The car overheated a couple days ago and was smoking around some of the spark plugs. The coolant was very low.) A month or two ago it was leaking on the ground, and I put in stop leak. Now I don't see anything on the ground (except from the cap the last 2 days), but it is going somewhere. I'll find out today whether I have succeeded.

GA from me for the most likely correct answer after a non sealing cap or/and overheating, which it appears not to be according to OP...

Assuming for the moment it is a blown head gasket:-

1) Remove head and get it planed flat, no matter how flat it may seem, make at least one cut that MUST "touch" the WHOLE surface. If the tiniest area somewhere is not "touched", make a second cut.......the WHOLE surface must look like new metal......

2) Clean all bolt holes (assuming not studs and nuts, clean studs if that is the case using the correct size thread) out using a tap of the correct bolt size, vacuum away all dirt removed. Check that bolts are completely free when threaded into position.

3) Replace head with new head gasket.

4) Follow correct tightening procedures using correct tools and fluids if required (some aluminium heads/blocks require this to stop electrolysis between steel bolt/stud and aluminum contact......

5) On some engines, new bolts are also required.

Hope that this helps.

Plastic reservoirs and plastic caps make for warped leakage.

These cars do have known head and gasket issues. The temp sensor is located on he engine, so it will likely tell you the truth. You honestly need to find someone with a pressure gauge and the adapter to test the reservoir. Run the car (get it hot), if the pressure never exceeds 14-16psi, then your cap or reservoir is bad. If the pressure does exceed that amount then you most likely have a bad head gasket.

From experience, you system was low due to a leaking water pump (hopefully not head), which allows air in. Air gets hot, expands beyond the capacity of the cooling system and puffs out the reservoir. You added coolant, left a little air bubble, then added more on level ground. Now it probably does not act up. You will probably find your coolant low again in the next few days.

Regardless you will need a pressure tester to find the leak or determine too much pressure.

Recommend to replace cap. You might have damage gasket or the spring on the cap is already weak.

check the cap. they are cheap. start with cap off to see if there is foam, fizz or big bubbles coming up constantly. may have a bad head gasket. problem with fords. may have a blockage in line going to recovery tank. most likely the cap if it's over a few years old. supposed to hold 16 lbs pressure to keep the coolant from boiling too easily. if it fails to do so it will leak coolant under normal temp.

First have a cooling system pressure test done! Newer use BARR's leaks on the ford, it forms a sticky goo, rust packs on to it and heattransfer is inhibited.[This is the cause of many cracked heads on the older v4 engines. Rather use Wynn's rad. stop leak or aqua clear.

If the head has been skimmed, screw the head bolts in by hand [without the head on] measure the head thickness and length of the bolts to determine if the bolts will hold the head down propperly.

Does the radiator fan work normally? If not check the motor and if it is ok, replace the thermostatic switch on the radiator [I usually fit one from the older Peugeots..it comes in earlier]

Put thermostat in allmost boiling water to see if it opens fully.

I once had trouble with a VW waterpump..plastic impellor that only sometimes came loose on its shaft..took some time to find it as it sat tight when cooled down! On Borgwards the distance between the waterpump impellorblades and the casing was too much and cause high speed overheating.

"Does the radiator fan work normally? If not check the motor and if it is ok, replace the thermostatic switch on the radiator [I usually fit one from the older Peugeots..it comes in earlier]

Put thermostat in allmost boiling water to see if it opens fully"

I don't know what is normal, they only run with the engine running. I give you a GA for the last part above. I have done this before and may still have to on this car. Today I saw the temperature indicator rise twice as much as normal toward the H, and then come down in a few seconds. No noticeable water leak, but it was not a hot day, and AC turned off.

Hi, you wrote:-

I don't know what is normal, they only run with the engine running.

If I understood you fully and correctly, this is wrong on many (notice I did not say ALL) cars. Most European/Japanese cars (we have few US cars in Europe in comparison) have temperature sensors/cooling fans that are independent of whether the motor is running or not.

It can happen that the cooling fan remains running until the cooling water has cooled down a bit, even though the engine has been switched off, or even sometimes that the cooling fan will come on AFTER the motor has been switched off !!

On hot days in multistory car parks in Europe, you can usually hear 2 or 3 fans running in the level where the cars are just being/been parked. Its normal business and a good thing as many cars experience a dramatic rise in cooling water temperature once the car stops moving through air, the engine is switched off and the forced circulation is therefore also switched off...

In my limited experience, this can occur for up to 20 minutes or so, and is probably a cause of flat batteries where the battery has seen better days! (Though I personally have never had any problems in that area!).

I would suspect that a damaged (always on) temperature sensor will probably first be noticed properly when the battery has been run flat.....

There is in many cars enough "convection" in the water system with a stopped engine, to rotate/move water between the radiator and the engine, on many models, against the normal engine driven flow......simply the water reverses direction once the motor is shut off. (notice I said many, not all!)

I have next to no experience of US built cars, except to know that they often do not follow any European "norms", so I have deliberately NOT included them here. The US market is different.

I hope you find this interesting.

Hi Andy,

Yes I know on some cars the fan(s) run after the key is shut off. Hopefully someone with a Taurus can answer this. Again today, my wife informed me, the temperature gage went above the usual setting for a short time, then returned to normal. What could be causing this? Of coarse I can't tell if the fans shut off at that time, but why would they? As for the water pump, I have been told they only fail by leaking (one person opposes that is this thread). Someone with Taurus water pump experience would be useful here. This doesn't sound like something a thermostat could do, so what does that leave? I have had this occur when the coolant level is low, but that is not the case here.

-S

It is not terribly unusual for a thermostat to stick and then release causing temperature spikes like you describe. This usually is the set up for the old stick closed and over heat routine.

Usually once they open, they work OK until the engine cools off enough for the thermostat to cool enough to close completely and stick again.

A related problem happens when the thermostat sticks open. Then you have trouble with the heater/defroster not working, the engine never heating enough to dry out the oil causing sludge and other problems.

I don't know much about the Ford Taurus specifically but I have worked on and around cars, trucks, tractors, motorcycles, combines, boats and industrial engines of many sorts since I was a little kid.

The fans on the Taurus are powered by the Constant Control Relay module which is controlled by the ECM. You will not see the fans run while the key is off.

The Taurus water pump has a metal impeller unlike the VW's lovely plastic impeller. I have seen a few metal impellers corrode away from the extended use of a pure water coolant. And you are right to believe that water pumps usually leak out of the 'weep hole (or make bearing noise) when they stop working effectively. If you remove the belt you can check the water pump pulley for any play to verify this. Also make sure it is not leaking from the bottom of the pump as sometimes it is hard to see.

The two most common causes for a fluctuating temperature gauge is air in the system or a restriction. We have almost ruled out air in the system as you are stating that the coolant level is not low. I could see hitting an air pocket once or twice after refilling a system, but not repeatedly. I am assuming by that you are also saying that the coolant level has not dropped?

A common restriction is the thermostat sticking closed. The major symptom for a 'sticky' thermostat would include the rise of the coolant gauge within the first 10 minutes of the car running and then the gauge would drop. After the gauge drops, it should not fluctuate again. Once the thermostat is open, it stays open.

Another cause of your problem could be the fans not working intermittently. The best way to diagnose that is to go check the fans for spinning when the coolant gauge is over normal.

I was a little concerned when you said you had put stop leak in the system previously. I have seen stop leak work wonders, but would not recommend using it especially on newer cars. Newer cars have less clearance in the coolant passages and most have aluminum heads. Stop leak can very well cause a restriction or create a piece of crud floating around the the cooling system randomly blocking a passage.

My recommendation as a former tech:

If you are not loosing coolant and your fans are running when the problem occurs, I would highly recommend draining your cooling system, getting a non-caustic radiator flush (good idea whoever said that) and following the instructions of the flush. If the drainings of the flush look dirty or rusty, repeat flush it until it comes out clean. Then refill your system with new coolant.

Good luck.

You seem to have forgotten what happens to the "Heat of combustion" that is still either in the pistons, or the metal of the head and block, that has not yet made it to the cooling water at the moment you switch off the big water pump (engine!).....

This heat will still get into the water of course, which is not now being circulated and cooled in the radiator, and will give a short rise in temperature of the cooling water. Depending upon exactly where the sensor is for the engine temperature and if it is still powered or not, AND you sit in the car and watch the gauge, many cars will exhibit this short rise in temperature....its a very common thing and nothing to do with any failures.....

Most temp gauges are powered off with the motor today, mostly people get out of the car when parked, many do not switch the ignition on an watch the gauge for 10 minutes, so it is seldom noticed.

In my early days of motoring, the temp gauges had a capillary tube and showed the engine temp at all times.....with no power (except at night when the little lamp was turned off with the headlights!!!!)

You are not the only one here that has never noticed this happening, anyone under 50 will probably never have seen it happen.......

Have a great day....

Hi Andy,

Are we having the issue of the temp gauge rising after the car is turned off or while it is running? I am under the assumption the gauge rises when the car is running. Am I mislead?

It was said that it rises after turn off (if I also understood that point correctly!!)

Have a great day.

On almost every car I have had, the temperature climbs for a short time after switching off, this is totally normal, forget this as being the problem.

This is the heat of the last few seconds running getting into the water AFTER the engine has been switched off. Nothing more, nothing less....

Get a flush and fill. You should do that at least once every couple years. I would replace the cap too considering they are cheap.

Steve

When my wife's Taurus began to use coolant and overheat, I took an old radiator cap and attached a small copper tube to it that I connected to my air compressor and pressure regulator. I pressurized the system to 15 psi and found a couple of pinhole leaks in rubber coolant hoses. After replacing the hoses, there was never another problem. This test is performed with the the engine cold, so there is no danger of getting burned.

I have to give you a GA for that one welderman I have never thought of that particular trick for pressure testing when you don't have the actual tool made for it.

My suggestion is to replace the cap and inspect the hose to the coolant recovery tank. If the hose between the tank and the cap/radiator is kinked or blocked, it will cause back pressure on the upper seal gasket of the radiator cap. This seal gasket is not intended to hold more than a tiny bit of pressure.

The purpose of the upper seal gasket is to seal the vacuum formed when the coolant shrinks as it cools. Maintaining this vacuum causes the coolant to be drawn from the recovery tank back into the radiator. If there is a kink or obstruction in the recovery hose, it will cause the upper gasket on the cap to leak when the cap gets pressurized with the displaced coolant.

I like the pressure test fixture idea for finding leaks by the way. Just be certain to limit the pressure to 15 PSIG or so to keep from destroying things that were not bad when the test started. ;)

TT3

A few important clarifications: The Taurus "radiator" does not have cap and there is no "overflow bottle".

There is a remote reservoir directly in coolant stream that also functions to remove bubbles from the coolant. The heater hose(s) also connect to the reservoir. This is the device that has the "radiator cap".

Considering the remote reservoir is directly exposed to the coolant stream, it is also under coolant system pressure. Warning: these plastic bottles have a history of splitting seams so a minor leak today can be a precursor to a major rupture next week/month/year. Replace the bottle ASAP but buy a new one because a boneyard reservoir will likely also be bad. They are fairly cheap from Ford.

Might as well flush the coolant while you are in there but don't use a caustic flush. Every time I have used one the heater core will leak a year later.

Try the cheap stuff first before worrying about the head gasket. If the temp is normal you should be fine.

I agree with the recommendations of first the radiator cap, I saved a friend $2000.00 for a head job by changing the $7.00 cap. A low coolant level will also cause the cooling fan not to function, as the temp switch is a "wet" sensor, it has to be submerged to sense the correct temp, the same goes for a gage or light indicator. With that said you should also check and keep an eye on your oil level, milky color or a rise in the level would indicate coolant getting pass the head gasket. If your mechanically inclined you should also check your spark plugs for moisture, another indicator of a head gasket. With side flow radiators it's hard to judge bubbles as an indicator of a blown head gasket, a radiator shop should have a chemical test kit for checking for hydro-carbons in the coolant, a good parts store may carry a kit you could buy. Main thing to keep in mind, "is to keep it simple". Start with the cap, check the coolant when it's cold, check the oil, spark plugs,and the thermostat. the thermostat can be checked by removing it from the engine and placing it in a pan of boiling water, if it opens chances are it's not the problem. It does sound like a cap to me. Good luck, DJ

I have owned a Taurus too. As mentioned by another responder, mine had no radiator cap on the radiator. It had a pressurized coolant/overflow reservoir that had the radiator cap on it. This is the typical configuration for a Taurus. After having overheating problems and leaking fluid problems (twice) and messing around with "all the cheap stuff" I had to replace that tank (twice in about 4 years). It was the problem both times. The Taurus has more of a problem with these plastic pressurized tanks than they do with head gaskets. As suggested previsouly, this is an extremely likely candidate for your problem. I would suggest it is the number one candidate.

To eliminate the head gasket concern once and for all, there are two easy simple checks that anyone can do and that you MUST do before tearing your engine apart and doing all that work and spending all that money for possibly nothing. When the head gasket blows, you will get radiator fluid in the oil and vice-versa. When the engine is cold, take the radiator cap off and smell the antifreeze. If it smells like oil, or you can see what looks like oil floating on the surface, you likely have a blown head gasket. Now, pull out the dipstick. Is the oil frothy and a little odd (more whitish) looking and smells different? If so, you definitely have a blown head gasket. If neither is the case, the head gasket is not the problem - thank goodness!

A leaking radiator cap is always a possibility. Replace it - it's cheap ($15 US). If you have just replaced it and it is still leaking, consider that it is also a safety valve and only designed to hold back a certain amount of pressure - the problem is elsewhere.

Leaking hoses are always a possibility. Check them closely. Even if they are not leaking, if they have gone hard or they are really squishy or spongy, replace them - they will be a problem shortly.

A stuck closed or partially closed thermostat is another reasonable candidate - and another cheap one ($6 to $18 US).

Unless your head gasket is gone - I'd check/replace the three things above first. They are all simple and all cheap.

Now we are back to the pressurized reservoir. This will run you somewhere around $30 to $40 dollars US.

All of these things are reasonably easy for the amateur to replace and shouldn't take long to do. However, if it turns out to be a head gasket (also a possibility), it is best left to someone more experienced.

If you have done what you know and still can't figure it out - take it to a mechanic and have it checked over. It is worth the peace of mind to know it is repaired properly and is reliable again - especially going into summer.

Good luck!

Your post has some merits and good points, but also missing a point or two! (I would not even be sure that I have mentioned all the possible missing points either!)

You wrote:-

...........If neither is the case, the head gasket is not the problem - thank goodness!

It could still be a head gasket problem! It is also possible that a bad head gasket leaks cooling fluid directly out of the engine, not into the oil......oil can leave a motor with a bad head gasket without contaminating the cooling water also.....

Furthermore, over and above a head gasket problems (on an Ford engine type that many say is plagued by head gasket problems.....), you could also have the following happening:-

If one of the caps that are supposed to drop out/get pushed out when the block freezes in winter is loose or not sealing, especially if its in an area not easily seen by anyone.....could cause water loss without oil contamination....or being observed.

Also, some engines have a water cooled/heated manifold, it is possible that a porous manifold could let water enter into the air stream and be turned into steam in the engine.....small amounts for instance, only when the system is pressurized, would not be noticed easily....

It is also possible that even when an engine is running, that small amounts of water can enter the combustion chamber via a bad head gasket, and get turned into steam and leave via the exhaust. Generally speaking this will also cause pressure to build up in the cooling system, but not always....

All of these points above I agree completely, are long shots, but they are still eminently possible, and should have not been forgotten, especially when you make statements as to what is ONLY possible, and they were all missing from your post!!! And as I mentioned at the beginning of this post, there could even be more that I have never heard of personally.......I do not want you to think that I feel that this list is now complete......its most probably not!!!

Have a great day anyway.....

Thanks for the "off topic" vote? ?? Whoever did it, it doesn't make any sense.

I have to agree that the things you mention may be possible and I actually have seen steam exhaust etc. However, in my experience none of those have ever happened when there wasn't also radiator fluid in the oil (in my experience). Obviously my experience cannot be all inclusive, especially since I am not a full time mechanic although I have done a lot of work on my cars and the cars of friends, relatives, neighbors and less fortunates who needed some help. I've replaced more head gaskets than I care to count or would like to remember.

Due to reading your post I asked a couple of my friends who are full time mechanics and two of the best I've ever met. In their combined 50+ years of experience only one of them had seen a blown head gasket (one time) that didn't get radiator fluid in the oil. It was, as you mentioned, blowing water straight out the side of the block. Obviously they can't have seen every car in the world break down but I think it speaks to the likelihood of the things you felt I should have included. One of them pointed out something that was a 'duh' to me after he said it; if you have water getting into the combusiton chambers, you have, by definition, cross-contamination of the two fluids. Both fluids are getting into the same space. He then reminded me that steam in the exhaust was another tale-tale sign of a blown head gasket but was not as likely or at least not as obvious in most cases as the mixing of the fluids.

I was trying to make two main points: !. Many posts seemed to be all for tearing the engine apart and replacing the head gasket without any checks at all and some without any apparent concern or thought for any other potential problems. This is foolhardy, especially for a less experienced repair person when there are so many possibilities for a less experienced person to truly screw up the engine or end up repeating the process multiple times. I was trying to point out that 2 simple checks could, for the most part, rule in or rule out the head gasket. I also told him that if he couldn't figure it out after trying what he knew; take it to a mechanic. The mechanic would be able to tell, after all the most likely and simpler things were done, if the head gasket was still the problem although this did not seem crucial to point out. From his initial post he seemed to be less experienced, consequently philosophizing on all of the possible scenarios of a head gasket seemed unneccessary and overkill. Being short on time it was also not expedient for me. 2. The most likely things in his case, although not the only possibilities, were the radiator cap and the plastic tank. From his last post it appears to have been the cap. As I recall that was your first guess too. So. Smile and pat yourself on the back. Your first advice to him was right.

Have a good day sir.

It is not rare to see engine coolant in the oil and not have a bad head gasket. The notorious GM 3.1L engine intake gasket is just one example. There are quite a few other scenarios to get the mix.

I am glad you are using the resources of both your experience and your friends to help others. The knowledge gained from these resources, including CR4 can be used time and time again. However, one thing I have learned from experience is to never say never, and definitely never say always. Anytime I think I am sure, something or someone finds a way to prove me wrong.

Since when did they put a GM 3.2L engine - or any of the others you alude to into a Ford Taurus? We are discussing that engine and its possibilities.

I wasn't really attempting to "never say never", just trying to provide the most probable and valuable information to someone such as the questioner in a very time constrained period. The information I gave, though sounding all inclusive was good information and by far most probable for that make, model and design. I can't believe so many people are having such a stroke over it.

Happily his problem is solved anyway - and he didn't have to tear his engine apart to replace the head gasket.

This problem is not solved if you would read Standard's posts. And the Taurus also has an intake gasket ;). Any relevant inputs?

GA for a good and accurate post.

I have also learned (the hard way...) never to say never, but some people never (sorry!!) seldom do!!

The reason I posted was you gave as a "fact" only two possibilities, oil in water, water in oil. Which is simply totally inaccurate!

They may cover 90% of the possible problems (seemingly not in this case, they found another reason), but it was not 100%. Only 100% can be termed accurate....

That was the only reason I posted.

You may have noticed that I also gave the problems I mentioned as only a remote possibility.......but still possible......and has been seen in reality!!

You could say I am the arch enemy of inaccurate sweeping statements....

Have a great day anyway.....

May I correct you, YOUR political process......

I live in Germany.........

It is unfortunate that we are all not as perfect as you, especially when trying to provide useful information to someone in need while under extreme time constraints. Blessings upon our comic book hero the "arch enemy of inaccurate sweeping statements".

On probability: It is also possible that a rock will jump spontaneously off the ground in front of your eyes. Jumping off the ground simply requires that all of the atoms of the rock be vibrating in the up/down direction in lock-step for a brief moment of time. It is completely possible, but the probability is obviously very small and combined with the probability that a human will be around to observe it makes the possibility vanishingly remote. I could have told him that rocks will jump off the ground while he is working on his cooling system, but the probability of that possibility is too small to bother making the comment. Is it too sweeping of an inaccurate statement if I had said that he will never see a rock spontaneously jump off the ground? After all, the probability, however small, does exist. When responding to a self-professed inexperienced weekend mechanic, why bother mentioning almost as remote of possibilities with that particular engine and cooling system design?

So you made a mistake and you want to prove it was not your fault somehow? That I was to blame because I was "perfect"??????Thats something new on both accounts!

I am far from perfect (major difference is that I have learned to live with that fact many, many years ago!). I also make mistakes and have had them correctly pointed out on CR4 as well. Its certainly not the end of a normal life for me when that happens......I make sure that nobody thinks that they got under my skin....even if they did, which is very seldom for me....

Just think about it this way, I was right, you were wrong, simply accept it and learn how to put a good face on it. Or put it another way, grow up!

Perhaps you will be more careful in the future with "sweeping statements", making sure they are totally correct before posting. You can easily lead others astray with such incorrect comments......

If you have learned something from my posts, then you have learned something very useful in your future life...... If not, there are many on CR4 willing to put you on the right path again, believe me!!!!

Perhaps also your CR4 name "urges" some of us on to find fault with your posts, its so "Big Headed" or "I'm the greatest!" so to say..........but its certainly your choice as to what you use and I can live with it as a name for you, but can you in the long run?

Your choice my friend..........

Have a great day in spite of me (but completely unintentionally) upsetting you......I did not realize quite how sensitive you obviously are to anything that smells of criticism.......

I have had a blown head gasket on a different make of car. When you have one, you get a big cloud of white smoke, and the car comes to a stop. However it could be leaking. I give you a GA for the rest. It is definitely ON topic.

Thanks guys for all the good suggestions. I have been a 'backyard mechanic' for many years, but sometimes need some 'moral support' especially when discouraged or short on time, so I appreciate it.

I have replaced the plastic 'radiator cap' which was on the 'remote reservoir'. So far this seems to have been a fix! It was only 5 bucks! I probably put $10-$15 worth of antifreeze in the car, so should have done it a long time ago. The old cap was built to 'click' like the modern gas caps (to keep it from being overtightened?) I never liked this 'feature', but maybe it was a sign of being broke? The new one can be tightened as much as you want. The only driving test yet to make is a long distance on a hot day with air conditioning on.

The car never appeared to leak when driving, but only after the car was stopped after reaching temperature. That's what made me suspicious of water flow issues. It has 2 electric fans on the radiator. They both run, but only when the engine is running. Turning on the ignition with the engine hot, but not running, does not activate the fans. Is this normal for a Taurus?

The 'remote reservoir' has 2 fill marks, but is not transparent enough to tell the fluid level. I have to find a stick to check it, so that makes it inconvenient. I will keep this in mind for replacement.

-S

I'd guess the leak is not actually from the cap. I have seen two instances (within weeks of each other) on taurus where the overflow reservoir was leaking from the bottom. The leak was at the plastic injection point of the molded tank on both vehicles.

To clear things up, I was talking about the temperature rising while driving. AFAIK, the spiking only happened once each trip. Yesterday I was informed that she drove my son about 8 miles with the AC on, and had no problems until she let him off after about 2 blocks of slow speed and stopping at the next stop sign half a block away after that. The gage was close to the H, so she turned of the AC and turned on the heater (as I had instructed). Once down, the temp was OK all the way home. This tells me there is not as much cooling capacity as there used to be. The flush is probably the next step. If that doesn't work, I may need a new radiator. Do you agree?

P.S. coolant level is not dropping noticeably. Maybe 1/8 inch in two days, but hard to tell.

Firstly, first class accurate info, that really helps us.

I tend to agree with the need for the radiator to be cleaned out, also the water pump (if not already checked out) needs to be inspected for completeness and tightness of the impeller. A damaged/not locked on the shaft impeller could give similar effects.

In the past, I have to admit to trying various methods to clear out a blocked rad, none of which worked......at least the effect of changing the rad and using the correct mixture of the correct type of anti freeze (is that the right word in English?), brought complete fixes. The chemicals not.

The reasons for this (in my experience only!) are that the small tubes clear only VERY slowly with any of the chemicals available, and I simply never had weeks of time to allow it to function fully......

One should NEVER refill a rad without checking and adding a good quality antifreeze too, otherwise calcium (in many water supplies) will settle out and "coke" things up.....

I have never tried it personally, but maybe a de-ionized or distilled water and antifreeze may be a better bet.......nothing to "coke up" the rad.......just a thought.

If you really need to save the price of a rad, try the chemical method (after checking the impeller), but believe me it will take ages.....

A new clean re-built rad is a quicker method that usually saves money and a lot of time........if available for your car. Maybe an wreck might supply a cleaner better one than you already have......look on the web.....

I realized I hadn't informed you of the problem. In addition to the radiator cap, the thermostat was stuck in, so I was right about no water flow. It is really amazing that it worked as well as it did. Running the heater didn't help because it wasn't putting out hot air.

Thanks everybody for your suggestions.

I am just happy that is fixed!

Not so fast. Today the temp indicator was back in the worry-some area (80% of the "normal" area), so I turned the heater on with the setting to full hot. The heater blew cold air again. I had checked it after the thermostat was changed, and it blew hot air then. The coolant level is fine, so what could be the problem?

Okay, I was hesitant to believe you had the issue described in the TSB link below, but now you have added a new symptom with the thermostat sticking. Also I am assuming you have the 3.0 Vin U Vulcan engine. From my understanding (which my comprehension skills lack) you would want to flush, install a hose bypass, and possibly a new water pump. Check it out for yourself and if you need any more info, please let me know.

Please Read (Ford TSB 01-11-6):

http://blizzard.zmm.com/waterpump/BrownCoolant.pdf