'98 Ford Taurus Water Temperature

Did you ROD the raditor ?

Most vechiles that are over 5 years old are running around with radiators that have at least 50% of the cooling tubes blocked and fliud can not flow thru them freely

When you rev up the engine your water pump drives fluid higher into the radiator then you get cooling.

Many people just add antifreeze or water and never flush or add rust preventive.

I started out by replacing the radiator cap because I did not know if it was holding the pressure. There were times when the coolant was boiling out. I did not always have the proper 50/50 mix and running mostly water probably caused the water loss and the rust buildup. I cut out a section of heater hose and installed a Preston flush tee and flushed the system. A radiator guy said he would not even work on that model of Taurus because it was so difficult to R&R the radiator. He suggested that I replace the thermostat as the next step after the radiator cap. I flushed again the themostat removed. I don't know if the original thermostat was not working, only that it had a lot of rust build up inside. I then check to see if my electric fans were operational and they were. At that point, I did not realize that there was a low and high speed.

The radiator shop said that he could do a better flush using air and high pressure water pulsations but it would cost $80 and there would be no guarantee that it would fix the problem. I thought about having the radiator removed and rodded but with the price of a brand new Visteon radiator only $115 including shipping from Amazon, it did not make sense to rod out my old one considering the labor for removing and replacing to be the same.

These engines are known for cracking cylinder heads and blowing head gaskets. It would be advisable to have a pressure test done on the cooling system with the spark plugs out.

Either of these two problems will make them overheat.

Hello Standarded,

I do not want to make you wasting your time, Seems like you know very well those

3.8 engines (Taurus 95):

-I am driving one and I may have a cracked head on it. Why?; I already changed the head gasket's, planned the head's and still have some white smoke comming out from the exhaust pipe.

-The shop who planned the head's already did a head pressure test and they confirmed that there is no crack. But, I am not sure about how serious they did that test!

-What do you suggest?; To buy two second hand heads from a rebuild-shop

and install them?

(It is a lot of work)

Thank you

Have a Nice Day

Nick

I don't know about models as late as 98, but several Taurus engines had head gasket, and a lot of times, head problems that all showed up initially as mild overheat problems. They always get worse if this is the case and will leave you setting with a cooked engine if you don't act on this very soon. Look for ANY small bubbles in the radiator to start with. On these problem models, just replacing the head gasket won't usually fix it. You may find a warped or cracked head or problems with the fit to the block. It usually is fairly expensive fix. I wish you the best, but I'm not overly optimistic about what you'll find.

Rust in the radiator? Did the engine get "real'" hot before the replacenment of the parts you listed. If it got hot you have probably injured the head gasket. Air is being injected into the cooling system and overheating the motor; it wont cool with air in the cooling sytem. The temperature gauge and sender do not transmit correctly in absense of water . Altho 140.000 miles seems a little soon for the thermostant to die the fact that you say you have rust in the system means that the antifreeze/coolant has gotten out of the correct percentage. This has probably eaten/eroded/corroded the aluminum cylinder head to the point that the head gasket cannot seal any longer. If the thermostat has failed so soon its probably because of the rust. The thermostat has to move with every change in throttle position to keep the motor at consant temperature. Rust in the system is very abrasive to this part and can cause it to sieze open(if you are lucky) or closed, which will burn up the motor real fast(if you are unlucky). Look for extra moisture in the valve cover, or a white milky "stuff" . Many times the head gasket will only leak compression into the water jacket before it leaks water into the oil. As posted before check for bugs that have decided to use your radiator for a mausoleum and besure that the radiator is really full of water/coolant, many cars need to have the air purged from the high spots in the cooling system......... good luck

the truth will coat you..... the sarcsm is free

I don't think the engine ever got "real" hot at least according to my temperature gauge.

I had been running mostly water because I had a leak in the heater bypass tube and kept topping it off with water. One time, long before this episode, I when driving on a hot day, I heard a banging sound and parked. I opened the hood and saw steam escaping from the pressure cap. After it cooled down, I put in a gallon of plain water and made it home without further incident. Having this much plain water probably lead to the rust and also clogged up the heater core.

There was no evidence that I know of that I blew a head gasket. I checked the oil for signs of water and found none. No bubbles in the expansion tank. Engine has plenty of power and runs good. No steam coming out of exhaust.

Now that I have all new parts, except for the water pump, I can't explain why it would be running hot when at a idle. The mention of air not being purged out may be on the right track. Maybe the flush I did with the old radiator still installed did not remove the sediment from the water jacket. There is a TSB on these engines because of a known manufacturing problem that left metal shavings in the block. When the mechanic put in the new radiator, I don't think he flushed the system again. I also do not know if he purged the air out of the system after the radiator installation.

My brother seems to think that the water temperature gauge itself could be wrong and suggests installing an aftermarket gauge. I am disinclined to want to do that since it would look like a total hack job. Maybe there is a way to install one neatly but at this point I am not wanting to do it. I may take it back to the mechanic and see if I can use his diagnostic instrument which plugs in under the dash and reads the coolant temp from a different thermocouple. I could then try to match the readings from my factory gauge to the test gauge. Again from my previous post, right after the new radiator was installed and it still showed high temp at idle, the test gauge seemed pretty steady at 224F while the original gauge moved down going from idle to 2000 RPM.

From all the boiling you spoke of I'd say your temp gauge is accurate.

From a lot of experience with these things, I would still advise doing a pressure check. They can fail to show water output (steam) at the tailpipe and still have head/gasket problems.

Also, the leakage area can "seal" itself unless the system is pumped up to operating pressure. In essence, the leak path may not be evident under atmospheric or less than maximum pressure. I've seen several in which no bubbling in the overflow/radiator was evidenced, along with no steam at idle, but still had head and/or gasket trouble. I base this upon 12+ years experience as a service tech, plus years as a factory field service engineer and design engineer for a major auto maker.

The test is too easy not to take a few minutes to verify the situation. It's cheap insurance.

I think that the rust is a clue. If you have so much rust that it clogs the thermostat at the top of the engine, consider how much rust is at the bottom of the water jacket surrounding the cylinder walls. I have seen this OFTEN particularly in inline six cylinder engines. The force of the water flow diminishes as it gets to the rear cylinders and particles (minerals in the water and inevitable rust particle) precipitate out, banking up against he back wall of the water jacket. When sufficient material accumulates, hot spots develop in that area due to water not being able to contact the cylinder wall. Under normal engine driving speed, enough water flows to cool the excessively heated water in that area and prevent a boiling condition. When idling, there is not enough flow and boiling occurs, causing some of the rust/sludge particles to dislodge and eventually flow through the system, getting caught in any restriction, like thermostats and radiators. In addition, boiling causes a more rapid breakdown of the cast iron block scale into rust/sludge and will also dislodge, as occurs when boiling out the cooling system.

I would suggest knocking out a freeze plug at the rear of the block to see if there is a build-up of sludge. Professional cleaning WILL NOT remove this impacted and "cooked" material. It is even quite a job poking at it with a screwdriver and garden hose. If this is your problem, you will be truly amazed that the engine didn't fry a piston. Besides, popping a freeze plug is easy and less than $5.00 to replace with a Doorman plug available at probably ALL parts stores.

Just a couple of thoughts:

1) These analog gauges are known for some strange and non-linear response curves. Our '94 consistently read below the "N" of NORMAL even on long drives. Idle in city traffic, and the gauge would go over the "M". Hooked up a Stewart-Warner mechanical gauge and found the total delta t to be about 12 deg. F. Same with a new gauge sensor. Ended up R&R gauge and marking dial face. Just living with it...

2) The actual test you need to run is called a "Leak Down". Using compressed air, 2 ea. 0 to 160 PSI gauges and a hose/fitting to fit into your spark plug holes, you seek the differential from the supply to the cylinder sides over time. Set-up takes some time as you need to rotate the crankshaft so that each cylinder's valves are closed (remove all spark plugs and radiator cap, please). At 141,000 miles, yes there will be a slow loss past the rings and perhaps some past the valves. This will take some time. Any rapid loss will be indicative broken rings, cracked valves and, in your case, a gurgling at the radiator cap neck from the cylinder(s) under test..

Probably NOT what you wanted to hear, but this is a method that the "shadetree" mechanic can employ him/herself.

Best of...

GLB

You can do a leak down test, and it can be helpful, but what I was specifically referring to was a cooling system pressure test in which you attach a pump to the radiator cap connector and pressurize the cooling system to the operating pressure with the plugs; you can often determine specifically which cylinder(s) have problems.

You can also have a hydrocarbon test done on the cooling system. A special adaptor with a test instrument is attached once again to the radiator cap connector. In this case, the vehicle is then started and run until the test temperature is reached in the engine. Hydrocarbons will infuse into the coolant from combustion and turn the coolant in the test apparatus a specific color, indicating a coolant system leak. Of course, this method does not specifically determine where the leak is.

Check the oil filter housing for rust accumulation or blockage in the water jacket, it's common bottleneck.

When writing a detailed or extensive post use a text editor then copy and paste.

Since you ran with mostly water as coolant you now have a lot of rust in the block.

You need to get rid of it as per. your rad guys advise . I would make sure your head gasket is ok . You can do the leakdown test but it aint cheap . To see if the head gasket is blown across the coolant passages , simply bring the engine to operating temp . " meaning the thermostat is open " and check for bubbles in the coolant . If there are bubbles " or oil " you have a blown head gasket . Also , since the overtemp. only occures at idle i would also check the water pump for good flow rate. Pull the hose at the outlet and see if there is good flow . Do you get good heat from the heater ? Pull the heater hoses off the pump and see if they are partially blocked with rust , if they are then that is an indicator of the condition of the rest of the cooling system.

Keep us informed as you go.

Also observe if you get excessive water vapor out the exhaust once the engine is up to temperature and while you are driving. Some may be normal with newer engine emission systems but if you look at it and say hmm, it might be another clue. You can cross your fingers and do a "throw $20.00 at it" repair by dumping a can of K&W block sealer into CLEAN (or as best as you can get it) cooling system water. It is a ceramic based sealer and is/was used by the NASCAR guys as a cross-your-fingers fix during races.

Head leaks are not the problem. Cooling fan controls are.

Taurus has a 2 speed fan control.

The relay center is under the fan shroud. The low speed fan is the one used in normal driving, being controled by a block sensor. The high speed is controled by a manifold sensor for ambient air temperature. If the low speed fan does not work, it WILL overheat in stop and go driving.

If the head leaked, it would overheat under a load, not at an idle. As long as the cooling fluid is normal colored, look for the fan control circuit.

In addition, my car now varies about one letter from off to on fan. About lower side of mid scale. The slow speed fan should cycle on and off under normal idling. There is a 2 wired plug sensor in the cooling path that controls this close to where the top radiator hose comes out of the block.

I would return the antifreeze/water solution to a 50/50 mix. Antifreeze raises the boiling temperature of the coolant so you won't see the boil over so soon.

Also, it will help keep rust from forming in the block and/or corroding the aluminum head.

Check for a soft (spongy) lower radiator hose - it may be collapsing.

GA for CrewChief - I agree on the impellers maybe the issue, and a tell-tale sign is that your coolant before you R&R'd everything was stained an off-color brown, or "not green"??

Just to bring completion to this thread, I found out that the impellers on the water pump were completely disintegrated. It was just a flat piece of metal spinning around. Yet there was no water leakage. The pieces that came off the impeller are probably lodged in the heater core. It is amazing that the car worked at all. This is such a common problem that Ford issued a technical service bulletin (http://rockledge.home.comcast.net/~rockledge/RangerPictureGallery/BrownCoolant.pdf) that recommended replacing the water pump no matter what the mileage or build date.

Thank you for the reply. It is all too often that we never hear from the OP. I once saw a 1972 Chrysler product with that same problem. But I thought those days were over.

It would seem that the problem is with AIR FLOW. If the temp is normal when moving and only rises when idling at a stop, there is obviously not enough air flow thru the radiator to keep things cool. Seems rather obvious, doesn't it?

I suggest looking at your water pump, perhaps the impeller is not what it should be. Next, do a pressure test; you may have a head gasket leak, or worse a cracked head or block.

It seems like the most logical reason for my car to still be overheating at idle after replacing everything that I did would be for the water pump impellers to be degraded. I thought the failure mode for a water pump would be leaking seals and I never thought to rev the engine at idle before my radiator was replaced to see what would happen. It seems logical that if there is some damage to the blades, there may not be enough coolant flow at idle speeds but when revved up it has enough cooling.

I guess at this point with 142000 miles on my car, I should change the water pump whether or not it is responsible for my current cooling problem. When I change the pump, should I get all new parts including the serpentine belt, idler pulley and belt tensioner? How critical is it to torque the bolts to the specified amount when installing the new pump? I don't know if I still have a torque wrench or not.

How difficult is this job for a novice with more time than money on his hands?

Hi aerospacecase,

Based on my previous experiences with a Taurus 3.8 model 1995 (motor Essex), I will not think that the water pump impeler is defective. (but, you should analyze and decide by yourself because I did not seen your car in order to be sure).

-Personally, I think that your engine have a head gasket problem, lower intake gasket problem, crack in the head or something like this whick make your engine to work in abnormal conditions.(start checking the thermostat, radiator, ... after think to a head gasket which is major and expensive problem)

-The water pump is what?; A metalic propeler on an axle!; Do you think that the respective propeler is rusted in such a way that in not moving the water into the circuit?;

-Personally I never saw a water pump with that defect; always the bering and seal was worn-out and I had to replace the water pump because of the collant leakage.

-The thermostat could be defective and not oppening at the respective temperature,

197F or whatever is written on the unit. (You can buy different models, 193F, ..).

-The main radiator could be locked with rust or other dirty things; You can wash this with your garden hose and ensure that there is good circulation

Good Luck

Nick

My problem was fixed a year ago. The culprit was a bad water pump. It did not leak and the seal was still good but the impeller blades were gone. All that remained was a horizontal disc... the vertical portion of the blades were gone. See my post #37 from 10/23/09

Hello again,

Serpentine belt: For Sure.

Idler Pulley: check to see if it has 'off-axis' wobble and/or sounds like a child's roller skate wheel.

Belt Tensioner: likewise for rotation as above and also for the spring travel/and stiffness.

The above are subjective judgements and are proportional to your desire to go back and do it again at some later date. The belt runs "everything" and is subject to typical belt decay. The others are rather robust in construction for such a small engine (actually used on larger Taurus 3.0 and Aerostar 4.0 units). You will find them Very Pricey at the dealership and only marginally less so at the Parts Store. Parts Store units have a provenance problem: you don't know where they came from and also high 'infant mortality (they crap out at about 600 miles, or just when you feel comfortable enough to take your first long trip).

Lastly, it is usually the Belt Tensioner Pulley that develops the signature Ford "squeak, squeak, squeak... ..." you hear at idle and low RPM.

The above are strictly the result of 'been there, done that'. Fancy analysis for MTBF, MTTR and TBO not included, but, available upon request...

Best to 'ya!!

In addition to your excellent suggestions, I would add to check the plastic pullys for wear. Some of them are prone to this.

Hi aerospacecase,

I had a previous thread about my 1996 Taurus losing coolant. I had a thermostat stuck shut. I replaced that and the cap, but the problem was not completely fixed. I looked into changing the water pump but it looked like a hard job. I think the power steering pump will have to come out. Mine had a hard pipe on it, so the fluid would have to be drained. I recommend a "power flush" by someone with the right tools and experience. It could be some small water path is plugged with rust or dirt. After seeing your thread, I think this model has a design problem. Good luck.

-S

And right you are. Both the 3.0, and the 3.8 engines required the PS pump to be removed first. And the bolts for the PS pump were behind the PS pulley, so you need to first use a special puller to remove the pulley. Ford, where quality is job 1. Engineering is not that high on the list.

A diagnostic instrument was plugged into the under-dash port and showed a steady 224F. During this time the dashboard gauge went from the middle to high and back while the 224F remained constant.

When the car idles and the temp gauge rises, when I rev the engine to 2000 RPMs, the gauge quickly returns to the middle position.

Seems like you have fault isolated the problem...not problem with everything but the dashboard (instrument panel) gauge! And/Or intermittent inadequate current to (resistance by) the gauge. Could indicate a failure of shunt in the gauge (Voltmeter) needle actuation cirtuit...such that needle input impedance is too low. I'd switch out the gauge for a known good one to see if the problem goes away (Remember, on a car old enough to need major cooling system renewal, the price of a gauge will not be a penny-rich, pound-foolish option--even if the old gauge is not defective.

It would be worth repeating the temperature reading test with a diagnostic computer before I spend any more money on something like a new water pump. I may buy and install an aftermarket temperature gauge to get a better feel for what is really going on.

After reading your post I tried the 2000 RPM thing and my dashboard readout came down too. check this out. I have since traded my car off.

StandardsGuy,

I have seen that TSB before. Too bad it is not an official recall that would be covered by Ford. They were calling for a water pump replacement on cars with less than 10000 miles in one of the 82 steps.

If you had the same result by revving the motor to over 2000 RPM, then what can I assume? Either your temp gauge is also bad or maybe you have a degraded water pump. I don't think the electric fan is directly linked to engine speed.

It looks like the water pump needs elective surgery, not an emergency operation.

"If you had the same result by revving the motor to over 2000 RPM, then what can I assume?"

I would certainly NOT assume the gage is bad. I would assume that there is not enough water flow around where the sensor is located. The reason could be restricted water channels or hoses, low output water pump, or bad design.

If the water level does not reach the temp sensor due to an air lock or low coolent, the radiator fan will not turn on, except when overheated and then it is too late hence the overheating. I finally pulled out the temp sensor and there was a big burb and then the fan operated as it should after that. By reving the engine you are forcing water to contact the sensor which turns on the fan but when idling the sensor is not making contact with the coolant.

Have you checked the water pump? with the motor shut off grab the pulley & see if you can rock the pulley. the best way would be to remove the belt & turn it free hand! also before that you could listen to the water pump with a stethiscope or a cheap way is use the largest screw driver you have put the screw driver on or close to the water pump when the motor is running be carefull & put your ear against the screwdriver! listen for loud scraping squealing niose! that is the next step I would do?

Are you sure the steam in the tailpipe is new? Could it be from before the heads were replaced? Are you lousing water? If so do you k now where the water is going? Test don't guess