Taurus Temperature Problem

Doesn't sound to me like a head or gasket problem. I'm assuming you havent found coolant in the oil or vice-versa.

Several things you need in a cooling system:

-Proper coolant flow (good flow, unobstructed)

-Proper coolant

-proper airflow.

-Good radiator cap and coolant tank.

-How's the flow? that would be my FIRST thing to check. perhaps you're missing a vane or two on the water pump or there is an obstruction?

-Have you flushed recently? maybe flush it in sections (gently). Could be the block sealers made the problem worse, too.

-Perhaps the fans ARENT really coming on like they should...or maybe not at full speed? They should have full ~13.8volts when engine hot.

-Temp sensor not allowing fans to go to FULL speed?

-Is the cap doing it's job? cheap to replace.

-Thermostat incorrect or incorrectly installed?

Don Byrer KJ5KB Radar Tech & Smilin' Commercial Pilot Guy Glider & CFI wannabe kj5kb-at-hotmail.com

"I have slipped the surly bonds of earth; now if I can just land without bending the gear..." "Watch out for those doves..."

To: snipped-for-privacy@softhome.net Subject: Re: Taurus Temperature Problem From: Moses Date: Tue, 15 Jul 2008 09:21:04 -0700 (PDT)

I'm having the same problem with my 99. The temp gage doesn't show overheating but the cololant will start to steam with the fans coming on after a short trip. It's likely the radiator is plugged. I've already replaced the water pump. Another possibility would be a blown head gasket, though the engine still runs smooth. A blown head gasket following a long hot highway trip is a trypical scenario. I'm taking mine to the garage tomorrow. My car has 163 k miles, what about yours?

Here is some background information which may be important:

The vehicle was originally taken into the dealer due to a heater problem. It took a long time to heat the interior because there was very limited heat output into the interior. The fan had to be on low to get any heat at all.

The dealer replaced the heater core. After this I am not 100% sure of what happened when. However, either because the car was overheating or becuase the heat was no longer working, the dealer replaced the thermostat.

After leaving the shop with the thermostat, the air conditioner would not work. A few miles down the road it started working. I think the overheating problem started after this but I am no longer sure.

At first the problem only seemed to occur after a very long drive with stops after the drive. It may have had the problem if I made shorter trips but I normally drive about seventy files each way before I stop. The problem continued to get worse, so I switched vehicles with my wife. The problem showed up on her twenty mile compute much more than on my long distance commute. She has to stop at lots of red lights.

I took the car back to the dealer and they said they detected a trace of exhaust gas in the coolant. That is when I decided to use the block seal. While flushing the system, I noted that the heater was putting out well. While installing the seal, I noted that the heater was not putting out. The thermostat was removed at the time.

After installing the block seal, I flushed the system and installed new coolant. The next day, I drove about 10 miles watching the engine temperature the entire time. The temperature was perfect when I stopped the engine for about 30 minutes. I then started and drove about five miles down the interstate. I exited and the temperature was still perfect until I stopped at the fourth red light. At that point, the temperature shot way up.

I immediately started the drive back home while attempting to avoid stops. I made the first red light but had to stop at a stop sign. The stop was very brief and the temperature was slightly high but did not seem to increase (probably had already lost enough coolant to explain the slightly elevated temperature). I drove 15 miles and the temperature remained the same. I stopped at another red light about five miles from home and the temperature started to increase after a few seconds. I drove the remainging five miles at highway speed with the temperature as before until I stopped in the driveway. The coolant was bubbling out when I stopped the car and the temperature increased.

Later that day, I replaced the coolant, added barsleak and idled the car about 15 minutes. The temperature increased to just below high and then decreased slightly.

After leaving the car off for a couple of hours, I made a trip about two miles up the road with three stops. By the time I returned to my drive way and stopped, the temperature was very high and the coolant was bubbling strongly.

Two days later, I drove the car about five miles and stopped for an hour. No problem at all. Got back in and drove two miles and there was a stream of coolant on the concrete when I left the parking lot. The temperature was fine for the five miles it took to return home but the resevoir was low on coolant.

Here are the resp>

I did not find any coolant in the oil or any oil in the coolant. Both appear clean. There was a trace of exhaust gas in the coolant which is why I applied the block sealer.

Is there anyway to check coolant flow without pulling the water pump?

I flushed it completely, after I started having the problem after the dealer changed the thermostat and couldn't find a problem.

I flushed it again to add the sealer.

It does not seem any worse and has not changed from before I added it.

I will check the voltage on my next trip out.

How do I check this?

I already replaced the cap which made no difference. I have since put the original one back on because the replacement seemed buckled.

I reinstalled the thermostat with the same orientation as the dealer which appears to be correct. The pointy end is toward the radiator. The jiggle valve is up. Unfortunately, I did not test the thermostat while I had it out.

.. Thanks, .. Commercial Pilot and CFIG .. What do you fly?

bending the gear..."

I have about 183 K miles on car. I have a noise from the "pumps" area but I think it is the power steering pump. I will be getting rid of the car soon but I would like to see it make it through the summer so I can take my time deciding on a replacement. If noremote t, I have a couple of deals in the works. Its a shame as it has four good tires, excellent brakes, great A/C, and no problems other than overheating (big problem).

The biggest remainging suspects are the water pump, cooling fan circuit, and radiator.

I have seem a lot of reports of vanes corroded away in Taurus water pumps so this seems a definite possibility.

There could be an intermittent problem with the coooling fans. I will check their voltage when I drive the vehicle again.

It could be the radiator but I don't think so. I got normal discharge flow when I flushed and refilled the system while attempting to resolve this issue.

I don't think the temperature sensor is the problem since temperatures read as expected before, during and after the overheating occurs.

The problem could still be a leaking head gasket or crack in the block. The sealant should have fixed this problem and there was no indication of such an issue when I checked the spark plugs, oil and coolant. No oil in the coolant. No coolant in the oil. No sign of a problem on the four plugs I checked.

The spark plugs were supposedly changed earlier this year. I checked the front plugs and the easy to get to rear plug. The front plugs were in like new condition. The rear plug had a normal appearance instead of a like new appearance. I wonder if the dealer "forgot" to change the back ones. In any case, I will pull the other two plugs if I don't resolve the overheating issue or trade the car in first.

I will let you know how I resolve the problem if I am able to do so.

Thanks.

I assume you mean the temperature system in the grey housing near the thermostat. Both radiator fans operate whenever the air conditioner is on so I don't think it should make a difference since the PCM would not need to turn the fans on since they are already working. I have never not seen the fans working with the A/C on but will make sure they kick in when the engine reaches temperature.

I will also check for 2000 ohms hot and 40000 ohms cold across the sensor.

Thanks.

it's either a bad thermosensor or your electric fan has a short.

Hello:

Thanks for all your suggestions. Based on them, I was better able to isolate the problem and eliminate some of the possiblities.

I ran the engine on idle for 10 minutes and verified the fans were working ok. I let the car sit for an hour and made two 3-mile trips. For both trips, the temperature gauge remained below the half way mark at the same point as in all my ford vehicles. The final trip home was at normal temperature. It was still at normal temperature when I stopped but I left the car running so I could check the radiator fans. It took me a minute to get the hood up and the radiator fans were working fine. I left the car running and the temperature gauge climed to a little more than 3/4 of the safe range and stayed there. When I turned the car off the temperature dropped 1/16 to 1/8 of the range.

I shut the car off and after a couple of minutes restarted it and checked the temperature again. It was now about 1/2 way on the guage.

After a few more minutes, I restarted it and the temperature had dropped to the normal operating temperature but increase after a minute or so back up to the half way point.

The radiator fans were going whether or not the A/C was on. Earlier they only ran when the A/C was on. I think the sensor and fans can be elimiated as a posssible cause of the problem.

I don't know how this works on modern vehicles, but the upper radiator hose is easy to squeeze. If I recall correctly from my younger days, this indicates a flow problem. That would point to either the radiator, an obstruction in the hoses, or the water pump. Is this correct and still applicable?

What do you think would be most likely and what should I do next?

Am I totally off track?

Thanks.

Hello:

Thanks for all your suggestions. Based on them, I was better able to isolate the problem and eliminate some of the possiblities.

I ran the engine on idle for 10 minutes and verified the fans were working ok. I let the car sit for an hour and made two 3-mile trips. For both trips, the temperature gauge remained below the half way mark at the same point as in all my ford vehicles. The final trip home was at normal temperature. It was still at normal temperature when I stopped but I left the car running so I could check the radiator fans. It took me a minute to get the hood up and the radiator fans were working fine. I left the car running and the temperature gauge climed to a little more than 3/4 of the safe range and stayed there. When I turned the car off the temperature dropped 1/16 to 1/8 of the range.

I shut the car off and after a couple of minutes restarted it and checked the temperature again. It was now about 1/2 way on the guage.

After a few more minutes, I restarted it and the temperature had dropped to the normal operating temperature but increase after a minute or so back up to the half way point.

The radiator fans were going whether or not the A/C was on. Earlier they only ran when the A/C was on. I think the sensor and fans can be elimiated as a posssible cause of the problem.

I don't know how this works on modern vehicles, but the upper radiator hose is easy to squeeze. If I recall correctly from my younger days, this indicates a flow problem. That would point to either the radiator, an obstruction in the hoses, or the water pump. Is this correct and still applicable?

What do you think would be most likely and what should I do next?

Am I totally off track?

Thanks.

You stated that someone had put in a new heater core and you think the problem may have started around that time. Have you rechecked all the work that was done at that time - maybe they reversed the heater hoses or installed the heater control valve backward or pinched/kinked one of those hoses.

The upper hose, being the outlet hose, is not usually a problem. A spongy lower hose can collapse from the suction of the water pump - but that is usually something that occurs at high rpm and your problem is the opposite - low rpm.

I would check that all hoses are going to the correct place, maybe check that thermostat again (even try running the car for a few days without it).

I think you have a bad head gasket. Block sealer was the wrong thing to put in, it never works. You should immediately check for water in the exhaust, for water leaks from the block, and for water in the oil.

Assuming you still have a 50/50 mix of water and antifreeze, smell and observe the exhaust when the car is hot. Then let it cool down and get cold then start it again, let it run a 30 seconds or so, then shut it off. If you smell antifreeze at any time from the exhaust, or any water dripping from the exhaust feels slick between the fingers or smells of antifreeze, your gasket has failed.

If the car is losing water and there are no leaks from the block the gasket has failed.

If there's water in the oil the gasket has failed.

The reason your cooling has shot to hell is because the exhaust and combustion chamber are at a higher pressure than the coolant, and exhaust gas is being forced into the coolant, causing air bubbles.

I think your putting your head in the sand and hoping it isn't a head gasket.

Ted

Actually, with the rarity of blown head gaskets on these cars, I would look closer at the water pump.

Late 90s Tauri have a bad habit of eroding the water pump impeller fins away. I would be very surprised if this car had a failed head gasket and even more surprised if it has never needed a water pump replacement.

A good shop can quickly test for combustion gases in the coolant to confirm or deny a head gasket issue.

Yeah, but most shops will lie and tell him the head gasket is blown just to make a fortune off the labor.

Testing for combustion gasses in the coolant is one of those things that if they do find them that is proof that the gasket is bad, HOWEVER if they DON'T find them that is NOT proof that the gasket is GOOD.

So in effect you cannot deny a head gasket issue simply by the absense of combustion gasses in the coolant.

Ted

I did have it tested and there were combustion gases in the coolant. I don't know if theu are still detectable after adding the sealant. I am going to get rid of the car despite it being in really good condition except for this problem.

If I were going to keep it, I would just replace the water pump, test/replace the radiator, test/replace the temperature sensor, replace the hoses, pull the head/repair, and replace the head gaskets. I could do most of the work myself and the replacement parts are not that expensive.

But the car is not a collectible and I am not a used car dealer so I am going to trade it in. I am trying to determine from the symptoms where the likely problem is and fix just that problem. I have one more clue and then I am probably done and will just move on to a new vehicle:

I took the car for a ride yesterday. I drove it 10 miles. The temperature was perfect until I stopped at a red light. It then began to rise slowly. I was at my destination about 1/4 mile from the light and the temperature had risen to the high end of the safe range.

I parked the car and used another vehicle to run some errands for about an hour. When I returned, I drove the car about five miles with the temperature normal. I then had to stop at a red light and the temperature shot up. It never returned to the normal range as I drove the remaining five miles home. It was not at the red but was probably about 80-90% of the way there. I stopped at the mail box and the car started pinging. I immediately drove the 1/4 mile home and stopped the car. Some smoke was coming off the firewall side of the engine. The temperature gauge was about the same as when I stopped at the mailbox. What's up with this?

Please keep in mind that the car does not seem to loose coolant while driving. But it boils out when the vehicle is stopped.

Thanks.

Obviously, if the HG failure is cylinder to cylinder or to atmosphere there will not be combustion gases in the coolant. A combustion leak into the cooling system (and subsequent overheating) will show gases in the cooling system

am going to get rid of the car despite it being in really good condition except for this problem.

So in other words, you're going to sell a lemon to an innocent stranger.

Hello:

I finally took the time to fix this vehicle. For anyone interested, I ignored the dealer and others saying the problem was the block and replaced the water pump.

There were no vanes left on the water pump. Cost about $40 including anti-freeze. Car runs like a champ.

Thanks, Sidney