Temperature rising

[1534dover]

I just bought a used 1995 Ford Taurus. I have noticed coolant on the garage floor from time to time, maybe half a cup. However, the resouvor is full. After driving in stop and go traffic the heat gauge goes way up. Goes down again when traffic clears. What is my problem?

[shorod]

The system will only pull coolant from the reservoir if the radiator is full. It's impossible to tell you what the problem without seeing the car, other than to say "you have a leak." You need to jack the car and support it with jack stands safely, then get underneath it and take a look. Is the leak towards the right or left side, forward of the engine or behind? Have the hoses been replaced recently, or are they original? Does the radiator cooling fan run when it should?

You may be able to borrow a cooling system pressure tester from your local auto parts store to pressurize the system to the proper pressure and see where coolant comes out, even on a cold engine.

-Rod

[1534dover]

Originally Posted by 1534dover

I just bought a used 1995 Ford Taurus. I have noticed coolant on the garage floor from time to time, maybe half a cup. However, the resouvor is full. After driving in stop and go traffic the heat gauge goes way up. Goes down again when traffic clears. What is my problem?

I found this under "Engine Coolant Temperature Gauge" in the Owner's Manual: "The pointer moves from the C (cold) mark into the NORMAL band as the engine warms up. It is acceptable for the pointer to fluctuate within the NORMAL band under normal driving conditions. Under certain driving conditions, such as heavy stop and go traffic or driving up hills in hot weather, the pointer may indicate at the top of the NORMAL band."

That's what I saw happening. It never went out of NORMAL into H because I put the heater on high and got rid of some heat. But according to the manual maybe it never would. If it does, the manual says Pull off the road, turn off the engine and let it cool off. Any more thoughts? Thanks.

[shorod]

Would you consider the driving you were doing "heavy stop and go?"

You shouldn't be getting leaks, you need to figure out what's causing that, you need to make sure the radiator is full (not just the reservoir) and you still need to make sure the cooling fan(s) are working properly.

-Rod

[1534dover]

Thanks for the tip. Yes, I would say heavy stop and go. I need to find the leak, however. It only leaks intermittantly, say once a week. Either that, or the leak is so small it evaporates before we use this car again. (We have another car) If the reservoir is full, won't that automatically fill the radiator?

[shorod]

As I wrote in the first sentence of post #2 above, the system will only pull coolant from the reservoir if the radiator is full.

-Rod

[thisnametooktolong]

First off that leak is the number one problem. It is probably leaking when the engine is shut off and on the hotter side. Good old coefficient of expansion. The hotter it gets the more pressure it has until it reaches the pressure set on the fill cap.

I hate to disagree with the other poster on this topic but the top of the water temperature gauge is well above 220F. on the 1996 and up cars the computer turns the fans on High at 216F. The older ones turn the fans on around 110. at that temp the needle on the temp gauge is probably pointing right at the line for the 20 MPH mark on the speedo. ( but that does very)

Every Vulcan engine is in the junkyard for the exact same reason. Over heated and blown gaskets/cracked heads. They all over heat for the same reasons. No water. And they have a bad Fan relay control module. Then comes the clogged radiator either on the inside or the outside

So if you would like to keep that car without spending the six or so hrs changing the head gaskets…. Find out if those fans are working. That and the stock thermostat may say 195 but it is not fully open until around 115. That is why I run a 185. They say that that temp is not available because the stock is slightly offset, but a non offset will fit just fine and work just fine

By the way I have a 96 with 2002 K miles on it.

[shorod]

I don't see where you're disagreeing with anything.

-Rod

[GPFred]

Something to consider. I have a 98 Taurus and I had experience with a similar situation. It turned out to be the overflow bottle was cracked on the bottom and allowed some leakage after driving and allowing it to start to cool down. I had to replace the bottle and I understand that this is a common problem for the earlier models.

[1534dover]

I took it to the shop and it cost nearly $500.00. It needed a new cooling fan. Apparently there is a two speed motor and only one speed was working and wouldn't do the job. They would only use Ford made parts because their experience with anything less hasn't been good. $180 was labor.

[shorod]

Thanks for the follow-up post, and glad to hear the issue is hopefully fixed. What did they do for the leak, or did they claim the leak was due to the system boiling over?

-Rod

[thisnametooktolong]

Originally Posted by shorod

I don't see where you're disagreeing with anything.

-Rod

That is because I was not clear and I did have a typo, Ford in all their wisdom (as well as GM and dodge) decided to trade temperature for fuel mileage. The hotter an engine runs the leaner you can run it until heat causes detonation. (Not all that leaner but better fuel anomiesation)
Mostly I was disagreeing with the idea that as long as it fluctuates in the normal range its A OK. The engine is expanding and contracting and therefore asking the head gasket to do a lot of work, especially on a bi-metal engines. The factory guage is a little slow and may not show the temp change for a while.
At the 2/3 mark that is around 225. The top of the normal range is around 255. That is way to hot. A 50/50 mix boils at 265. With an average temp of 235 I know for a fact that parts of the internal engine is over 265. At those temps I bet the inside of the engine looks just like a pan of water on the stove just before it starts a violent boil.( Little bubbles rising and a funny noise). There is no BTU buffer for what ifs and may-bees. The typo was that I stated the factory stat is not fully open till 115 it should have said 225. And my though on the subject of fluctuating temperature that I left out is: That is not good for anything. It is not good for the engine to run hot as heck because the oil does thin out. It is not good for the head gaskets to fluctuate with all that expansion and contraction going on. On an older engine that is running close to max bearing clearance on the rods. The round end expands making the bearing clearance out of spec. That combined with oil that is hot and therefore thin can and will cause problems. Ever notice that bearings spin more in the summer than they do in the winter? All of the engineers have the cars running on the razors edge as far as heat goes. That is fine and dandy when it is new, but not a good idea with a bunch of miles on them. A hot engine can and will go into thermal runaway because glycol dos not like to dissipate heat as well as it takes it on. This is amplified in an older engine that is not shinny new on the inside and a radiator that is a little dirty on the in and outside.
That is why when I purchased my sable I took the darn thing and rewired the CCM so that fans are always on low, turn on high whenever the A/C turns on. And turn on high as the factory computer says at 216. Then I placed a 180 t stat in it. Now the temp stays between 184 and never above 195, and the head gaskets are holding with 202K miles. But it does kill the alternator (life time guarantee… no problem)
As a side bar, if the fans do work on low and not high, the way the commands go to the fans, it is better to turn on the AC with the temp set to hot, and yank the wire to the A/C clutch, than it is to just turn the heat on. With the temp set to high and the core has water flowing through it and the fans are turned on.

And yep I know what happens to the heat in the winter, and what happens to internal engine ware below 180F.

Remember that I am not an engineer and this is just my thought on the subject, but it does seem to work.