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Discussion Starter #1
This condition just started to really get worse in the past few weeks and i am afraid trhis summer i will not be able to drive the car. Well this is the problem, it is a 89 mustang gt with a 302 HO EFI, underdrive pullies, 180 degree thermostate, K&N, and an H-Pipe otherwise a stock motor. Well when the car sets and idles it slowly climbs on up to 250 degrees and then overheats. It is also using water, not alot but it is using water. I left it in the garage for 2 days and no water on floor and no visible leaks so it has to be using it. Could is be a possible head gasket or do you think the heads are gone for good? Or does anyone else know of a condition to cause this problem. Going down the road at 60 it runs a cool 170* But in heavy traffic and stop lights it rises to about 200* to 220* Also one more thing, when i cut the car off the temp guage goes on past 270* Thanks for any and all the help!!!!
 

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Time for a pressure test on the cooling system. If it's dropping pressure and you don't see water, it's gotta be going somewhere and that's not good news. I'd suspect a headgasket first.
 

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I would think if the water was "being consumed" by the engine you would have obvious signs of either ... White smoke in the exhaust from it entering the cylinders ... or ... Foamy looking oil from it entering the crank case.

Short of those two things is could be blowing out the over flow tube from the overheating. One would think you would see signs of that in the garage floor though ... but maybe not if the thing has cooled down to a reasonable level before you park it back at home.

If it stays cool while the car is at speed ... I'd start looking closely at the radiator for a sludging up/plugged cores problem ... or an air flow problem.

Pressure test would be a great start though.

This is all assuming you have not changed anything with the tuning of the engine ... fuel mixture and timning "can" affect your ability to keep at proper operating temp


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Larry Madsen
Las Vegas Nevada



<font size=-1>[ This Message was edited by: monstermach on 3/17/02 6:12am ]</font>
 

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What sort of fan do you have?If it runs ok at speed then there is a airflow prob when stationary.If it has electric fans check they are cutting in,if it is a clutch fan maybe it's shagged..
 

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Pressure test first.
You can check the core on the rad by running it and feeling the core with your hands.
If the bottom third of the core is very much colder than the top third you probably have a rad full of sludge.
Still doesnt explain the coolant consumption though.
You can check for loss into oil by running it up hot at night. Let it go cold overnight and first thing in morning drop a half litre or so of oil from the cump.
Water goes the bottom, so if theres a reasonable amount there (50ml or more) it will show up.
If you are losing it into an intake runner or cyl head you shoudl see evidence on plugs too and piston tops. If you can pull plugs and shine torch in cylinder while piston at TDC and check for odd colours between cyls.
 

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I've found one way to test for a blown head gasket is to open the radiator cap and then idle the engine for a bit until the thermostat opens. You'll be able to tell because you'll see the coolant flowing through the radiator cap. If it starts to bubble, then you've got a problem. What happens is the compression from the heads will leak into the coolant and force its way up into the radiator.
 

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Discussion Starter #7
ok guys, here's the latest scoop from what you all have told me. The oil is showing no signs of water at this time. I have advanced timing but I drove the car for 4 months after that and nothing overheated. About that pressure test on the cooling system, how do you do that? The car probably uses about a gallon of water every two weeks. Also when the car warms up fully i do still see a small amount of fog/misty air coming from the passenger side tail pipe. I done a compression test and every cylinder is showing 160 to 170 psi and this is on a 141000 mile motor! Well preciate the help and let me know about that pressure test. Thanks
 

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you need a special tool to pressure test you car. you could take it to your local shop and ask them to help you out or buy one. if you get a good one like the snap-on one like i just got for work its a couple hundred dollars. did you try replacing your T-stat? it might be stuck closed. happens alot to fords that i see come into work.
 

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How long have you had the underdrive pulleys? Do you have a electric fan or mech? If your going to pressure test your cooling system, take it to a radiator shop...you only want about 4-6 pounds of pressure or you will blow out your heater core.
 

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Discussion Starter #10
The underdrive pullies have been on it since i bought the car and they have run fine. Also I have a mechanical fan, that could be screwing up but how do i check that? I just replaced the thermostat with a 180' one and i am pretty sure that is working since it worked and ran fine for a while after replacement. I will see what i can do this weekend as for the pressure test. Thanks guys, and gals if any out there!!
 

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If I am not mistaken, doesn't that fan run off a screwy clutch system? You could have an intermittent prob with the fan clutch or even the shaft has come loose from the impeller in your water pump

heat the car up with the radiator cap off and watch to see if you get water flow at various RPMs. This will eliminate your water pump impeller as a source.

Also, the underdrive might be fooling your clutch to the fan somehow. I don't know the exact mechanical workings of the fan clutch, but I have never cared for those setups so I went electric.
 

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Discussion Starter #12
Well las tnight i went for a spin and when i got back i cooled the car down enough to get the radiator cap off then warmed the car up and there is flow so the water pump is working, also the overheating in traffic i suspect was from the water level being about a gallon low, however i do see small bubles appearing in the radiator so i suspect a blown or leaking head gasket. I am going to pull the plugs tonight and take a look at them. Well see what i come up with!! Thanks
 
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