Overheating still

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AutoSHO

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Sounds like a thermostat problem.

Also - Have you replaced both the upper and lower radiator hoses? they can have an internal restriction that doesnt show up until they get hot.

If the car is getting cool without the thermostat and driving on the highway, then it sounds like the thermostat isn't functioning properly or your car is creating too much heat in the engine which necessitates the extra coolant flow provided by the missing thermostat. Sounds more like a bad thermostat to me. Are you using a genuine motorcraft?
 

BeatDaSHO

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I did not do a flow test through the radiator because it is a new radiator and it didn't make a difference. I have tried 4 different thermostats.......2 motorcrafts (192 degree ones because they don't sell the 180's anymore.....the one that was in there before the heat problem was a motorcraft 192 so i replaced it with the same thing), a napa 180 degree (i tried this one two years ago and it ran wayy too cold yet now it ran up to 220), and an Autozone 180 degree (which runs all the way to 220 also).

I replaced the lower radiator hose. I put the upper radiator hose in boiling water and it did NOT close so that is fine.

Any more ideas? Thanks for everyone's replies.

Greg
 

Off Road SHO

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BeatDaSHO:


I put the upper radiator hose in boiling water and it did NOT close so that is fine.



Greg
Greg,

Are you thinking that by putting the hose in boiling water, a defective hose will collapse? That is not the case. What really happens is that a defective hose gets so soft under heat load that it collapses from the "suction" of the waterpump. A good hose will not collapse under a slight vacuum.

Tom
 

BeatDaSHO

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I saw numerous posts through the search function about putting the upper radiator hose in boiling water to see if the insides would collapse. I guess all of those posts were wrong. My bad. Do you think this might be my problem then? Should i try replacing it? Has anyone else had the upper radiator hose go bad on them?

Another thing I was thinking.....can the hoses to the heater core go bad and prevent coolant from flowing through? Would it be worth trying to bypass the heater core? By the way, the heat works great.

Greg

<small>[ July 15, 2003, 05:20 PM: Message edited by: BeatDaSHO ]</small>
 

unterhausen

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Ok, here's my theory. You have a dying water pump. Even with an open thermostat there is enough backpressure to drop the flow to nothing.
 

AutoSHO

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unterhausen:
Ok, here's my theory. You have a dying water pump. Even with an open thermostat there is enough backpressure to drop the flow to nothing.
He mentioned replacing the water pump already.

I think it might just be the upper rad. hose.

If not, I don't think there's much left it could be. If it cools on the highway, though, then I dont think you have anything to worry about.
 

BeatDaSHO

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One thing I noticed today.........I sat just idling for about 10 mins. The temp stayed around 185. As soon as I started to go, the temp rose to 195.....isn't the car supposed to heat up while sitting there and cool down while driving?

Greg
 

projectSHO89

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Since it heats up while moving, go check your front air dam.

There's supposed to be a deflector there that pushes air upwards and through the radiator when the car is in motion.

While in motion, the engine creates more heat because it is working harder. If the airflow though the radiator is insufficient due to a missing deflector or some other reason, it can cause your symptom.

Steve
 

BeatDaSHO

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Yes, the air dam is intact. I just did a prestone flush but this time with the chemical flush. Still no difference. I can't be the only one with this problem.

Greg
 

Off Road SHO

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I would check your temperature sending unit for accuracy, an infrared temp reader pointed at the thermostat housing will let you know what the exact temperature of your water is. I just did mine yesterday and it read 183 degrees when the needle was between the A and the L.

Then I would do a pressure test on the system and on the cap.

Then I would do a flow test on your water pump and system. You will need to have the thermostat out for this test because the thermostat closes when it comes into contact with cool water. Disconnect the upper radiator hose from the radiator and add a piece of PVC pipe to it so that you can see the water come out of it and it won't splash on your engine.

Tape up the end of the garden hose so that it fits snug in the radiator's upper hole.

With the thermostat out (while you have it out put it in a pan of boiling water and make sure it opens completely) and the gardenhose on, you should get good flow through the radiator, water pump, block, heads and thermostat housing. Got good flow? No; look for blockage. Yes; go to next step.

Next Step
Turn on garden hose so that you can see some water coming out, not a lot, just enough to say fill a quart jar in 5 seconds. Once you have a moderate flow through your engine from the force of the garden hose, start the engine. The flow should increase dramatically from the turning of the water pump. I found a sheared shaft on a water pump this way years ago.

You need two thing to keep a water cooled engine cool: Water flow and air flow.

Good luck and sorry for the long post
 

NASCAR Mike

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I would buy one of those test kits that checks to see if there is exhaust gasses in your antifreeze.

Having blown about 3 head gaskets on my supercharged 94 Mustang GT, I can tell you that the leakdown tests are not all accurate. A pinhole in the headgasket might not leak at all during a leak down test, but it will when the engine is running. I can't image how much pressure you would need to simulate the explosion of air/fuel in the cylinder for the leakdown test to be accurate.

One other thing, how is your fuel pump? If it's dying it will flow less fuel, hence you will be running lean. Lean condition means extra heat. At idle you don't need much fuel but when you are driving you need the fuel flow. Also check your fuel filter. If it's clogged it will reduce fuel flow. Hook a pressure gauge onto the fuel lines at the schrader valve and see what the pressure is. It should be above 35 at idle and over 40 with the vacuum line off the fuel pressure regulator.

It appears you have done everything else right check your antifreeze for gasses and then your fuelpump for pressure.
 

BeatDaSHO

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Off Road SHO..........I completed the one test where you put the garden hose in the upper radiator hole and see if you have good flow.....very good flow....then i turned on the engine and i got even better flow because of the water pump. Passed that test. The thermostat is opening also.

Question.....The upper radiator hose is just rubber so how can the "insides" collapse like people say they can? Should I replace this?

I am going to have to get the chemical test kit to see if I have a bad head gasket. Only thing is, my car runs reallllly strong and wouldn't a leaking head gasket hurt performance?

And if I didn't have enough fuel going to the motor, wouldn't that hurt performance also?

Thanks guys for those long writeups.

Greg
 

Off Road SHO

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BeatDASHO,
The hose sometimes is made out of two types of rubber. One type that resists heat, coolant, oil and gasoline, is the inside layer. The outer layer has to resist heat, ozone, abrasion and being squeezed for the burp test.

It's that inner layer that sometimes gets very soft and weak and separates from the outer layer. Under the slight vacuum in the coolant caused by a closed thermostat and a spinning water pump, that soft inner layer will partially block the coolant passage. If you have any doubts, just replace it.

Tom
 

NASCAR Mike

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BeatDaSHO:
And if I didn't have enough fuel going to the motor, wouldn't that hurt performance also?
Actually you make more power when you lean the car out. That's what most aftermarket MAF's do, they lean the fuel curve, sometime too much.

Run too lean, overheat and pop head gasket. Run too rich and you foul your plugs.

By checking your fuel pressure you elimate that as a factor in the overheating. You almost need to make a check list of things and cross things off after you complete them. This will narrow down your list of unknowns to a few and hopefully as you get towards the end, it fixes it.
 

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