5.0 high temp problem

terr5178

New Member
May 1, 2008
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I believe my car is just a 3 season car. It doesn't like the summers. I have the 5.0 with headers cold air intake, a/c eliminator, 50/50 antifreeze and 3 tube radiator with a flex fan. At highway speeds with the thermostat installed I was running right around the middle . In traffic it would travel all the way to the last hash markbelow redline. I changed the radiator cap and removed the 180 thermostat but it still tends to run hot. With the thermostat removed and 90 degrees out I run just above the middle of guage at highway speed it creaps up to the last hash mark in traffic.
I don't know if the guage is correct because it hasn't boiled over yet. what can I do to get the temp down to normal? Does a flex fan work better than the clutch fan? I don't want to put in an electric fan. what will a gunked up radiator look like on the inside? how can i clean that out?
 
To start replace the T-stat. If you run without it the water will run through the radiator too quickly to cool properly. Your flex fan isnt the best in a FOX based car. Get the stocker and make sure you use a new clutch. One trick I did was to get the 93 Cobra water pump pulley. This is a smaller pulley and causes the pump tp move water faster through the engine.

Your post didnt say anything about mods so I am assuming its stock.
 
Put a good brand t-stat in. Removing it is a band-aid.

Flex flans can also sometimes cause issues like this. If you have the stock clutch driven fan put it back on.

Flush the rad and check the condition of the fins. If a ton of fins are bent and the inside is cgunked up with deposits, consider a new rad.

Make sure the deflector under the bumper is still mounted.

Do you have underdrive pulleys?

Fresh 50/50 mix with distilled water and water wetter.

Also, stock gauge blows. Get an autometer gauge.
 
I have the fan shroud, the lower air dam installed and I have just installed a mr gasket 180 t stat. I also did the radiator flush. Is there anything stronger that would work? The temp is still high. I did notice grey deposits on the water tubes in the radiator. How can I break these down or do I just have to buy a new radiator.
 
The water pump is a reverse direction pump. The fan also needs to be as it can spin two different ways depending on the 5.0. Is the fan the proper one which sucks air through the rad when it spins?
 
Yes, the fan blows the air the correct way. If the radiator was gunked up, what would it look like when I look at the tubes through the radiator cap? Mine has a gray/white crust on the end of the tubes. Would that be enough to cause bad flow?
 
you can get the radiator rodded out by a shop but I would replace the fan with the stocker just to make sure its not the fan. Temp issues are very simply to fix, air flow through the radiator, water flow through the radiator and pressure leaks are most issues. Also check the timing too, if its too advanced it will heat up the heads and cause overheated conditions too.
 
if the inside of the radiator is all gunked up im sure its not going to help...when i first bought my car it had that and after i replaced the radiator it always ran a little cooler... if you dont want to spend alot you can get replacement rads from the auto parts store for about 100 bucks...

jim
 
Ya, It is a 3 core radiator already. I unfortunately dont have the stock fan so I have to find someone getting rid of one. Can anyone give me a description of what the deposits would look like in the radiator so that I know what im looking at is the problem. The radiator looks clean except for the gray deposits on the water tubes. Is that enough to cause the heat problem
thanks everyone for the feedback
 
I'm not sure I followed you. It sounds like the car runs ok until you are in traffic, which suggests a fan issue. If you run cool enough at speed, the radiator is capable of rejecting enough heat and should not be the source of issue.
 
It runs about 215 on the highway and up at the top of the guage near the n when in traffic. If I get on the highway after sitting in traffic it will take a long time 20 miles for it to come down to a more acceptable level. I know it is either the radiator or the fan but I don't want to waste money on replaceing the wrong part. Are there any ways of checking the fan and checking the radiator? I hate throwing parts at a car it gets very expensive.
 
the only time i have had a 302 run hot is when i had a head gasket problem with the block or head being warped ! you can tell if the radiator is cloged by feeling the radiator for cool spots while its running. i would put my money on radiator clogged or head gasket ! next time you start your ccar from sitting long enough to cool down some check and see if it builds up pressure fast if it does it will be a gasket !
 
my thought also but i guess when things start to get old the flex fan doesn't push enough air at higher rpm. maybe the blades are not the same angle when new or the rad needs more air due to poor cooling qualities of an old rad.