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Discussion Starter #1
I need some ideas for my fox body, it is overheating, it will idle all day just fine but as I drive it the temp just creeps higher and higher. It is a 466, cobra jet heads (aluminum) 10.5 compression, hydraulic flat tappet, 850 demon. It has a afco radiator 2 1.25 thick rows. Twin 12inch spal pullers with a shroud that covers entire radiator. 185 thermostat with bypass holes drilled, ford motorsports water pump . A couple of things
1=When the thermostat opens there is alot of foam
2= My wife overheated it bad last year, it was blowing steam and temp guage was pegged but she kept driving it because "she only had 10 blocks to go"
3=No water in oil or vice/verse
You think it could be a damaged head or gasket? Could the water pump be bad?
Thanks for the help,
Mags
 

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magmanmick said:
When the thermostat opens there is alot of foam. Thanks for the help, Mags.
I would perform a compression test to find a 'low cylinder', then a cylinder leak down test (with radiator cap off) to find the fault with that cylinder. Sounds like a blown head gasket or a cracked cylinder head.
 

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Discussion Starter #3
Thanks Danny, I appreciate the way you are "Johnny on the spot" to help everybody out. I do have a cylinder that is down about 20 pounds from the rest. Do we have a post about a leakdown test? I guess I will have to buy a leakdown setup huh?

Never mind Danny, I found your response to this question in another post LOL.

"You'll need a cylinder leak-down tester with it's included instructions."
 

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magmanmick said:
Thanks Danny, I appreciate the way you are "Johnny on the spot" to help everybody out. I do have a cylinder that is down about 20 pounds from the rest. Do we have a post about a leakdown test? I guess I will have to buy a leakdown setup huh?
Thanks. A compression tester can only indicate a bad/low cylinder; a cylinder leak down tester indicates why that cylinder is bad/low. This one works well and is inexpensive:
http://www.thetoolwarehouse.net/shop/AP-7751.html

(You can also turn down the pressure on your shop compressor and attach the air hose to an 'air hold' tool; sort of a poor man's leak down tester - it works.)
 

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Discussion Starter #6
Ok so I ran a compression and leakdown test, I found 165lbs. in all cylinders but 3 and 4 which are at 150lbs. also all cylinders have 25% leakdown except 3 and 4 which have 35%-38%. Coupled with the overheating do you think I have a problem with the area between 3 and 4 cylinder? Head gasket cracked head or block maybe? I don't want to tear it apart for nothing. On a side note 25% leakdown seems a little high does'nt it?
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Foamy coolant? Time to change your engine coolant (this is a characterisitic sign of depleted properties of the coolant). Gaseous foam/air bubbles in the coolling system will cause the temp proble to read high.

The above statement assumes there is nothing else wrong with your engine (such as other possible considerations above in this thread). Just wanted to point out this one thing about your symptom(s).

Paul
 

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I would change the coolant because it is cheap and easy.When my racing motors went past 25% I took them apart.I have had motors that would show good on a leak down test but under load they would push a little water out and run hot.One was a crack starting in the head the other was the gasket.
 

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Did air come out of #3 plug hole when you where leaking #4?
Or vice versa?

Did you take the rad cap off and check for air bubbles in the coolant when you where leaking 3 or 4?

Either way sounds like you have something significant going on between 3 and 4 for sure. I would be pulling the head to check for sure.

dkp
 

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Discussion Starter #10
Sorry I did'nt specify, I am running water not antifreeze, the air was'nt coming through the radiator. I know it was going into the crankcase, but could'nt tell if it was going to the cylinder next door or not. I think I will tear the head off later today, I can't drive it how it is anyways. Thanks for all the help!!!!
Mags
 
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