new thermostat & water pump..still overheating, help!b

[fongo]

Memorial Day weekend blues for me!
On my 93 5.0, I just put a new water pump, new thermostat 180 deg, hoses, flushed out the Motorsport 3 core radiator radiator...
After turning the car on for a about 15 min & running the A/C, my car temp gauges starts climbing towards the 270C limit. I checked everything: no leaks, new parts, fresh coolant etc. I did put on a new 95 amp alternator (PA perfmce) yet I dont anticipate any problems? The serpentine belt is tight to specs.
However, after I ride the car around the block a few times, the temp gauge does go down? Could it be a defective radiator? It does get hot though. Could it be that the radiator is not compatible? It is a little thicker than the stock and the fan shroud tends to be more closer to radiator than before. Need some tips.
Thanks! Hapypy Holidays!
fongo

[Hammer]

First of all, are you sure that you just don't have a defective temp guage? The temp should go down as you drive it around as you have more air going through the radiator. That's why engines can sometimes overheat in bad traffic during the summer down here in Texas.

[rwhite65]

Do you still have the clutch fan? I would check to see if it is still working. I have had my radiators clogged enough that I actually had to take it to the radiator shop and have it cleaned out by them. They would remove the caps for you and rod it out I believe.

Ryan

[Rev]

Originally Posted by rwhite65

Do you still have the clutch fan? I would check to see if it is still working. I have had my radiators clogged enough that I actually had to take it to the radiator shop and have it cleaned out by them. They would remove the caps for you and rod it out I believe.

Ryan

That's what I was going to suggest also about the radiator. I've had to to do that several times over the last 10 years.

Rev

[Lethal5Oh]

Are you sure you have ALL the air out of the cooling system? Air pockets at the t stat will make it look like your overheating till it pops.

[fongo]

Thanks all!
Lethal50, I actually flushed the radiator with lots of water @ high pressure with a garden hose. Is that enough? I also bought that cool solution (red bottle..i forgot the name) from A*tozone. I added to the radiator and so far it's a little better. As long as I don't rev up the engine, it hangs around 190deg for about 20min at idle (then it starts climbing up towards the 270deg mark).
I also replaced the temperature sensors in the engine (but not the gauge..no reason to, right?)
Thanks all for the feedback.. I'll keep you guys/gals posted...
fongo

[Lethal5Oh]

flushing the radiator isnt enough. the best way is to use a vacuum bleeder (i think you can rent one at autozone) or theres a funnel that has adapters that fit inplace of the rad cap. I know mac and matco sell them or i know ive seen them at walmart or autozone. Its called the spill proof funnel. good luck

[~The Jester~]

I'm going with air pocket, or fan issues. Clutch fan or aftermarket? If aftermarket, not trying to sound stoopid or anything, but make sure it's not on backwards. I've done that before.

Ryan is talking about the radiator being clogged on the OUTSIDE, not internally. In other words, bugs, cat hair, dirt, etc etc get stuck on the outside of the radiator, blocking any air from flowing through it.

Didn't run over any squirrels lately did ya? hehehehehe

[94snake]

im gonna go w\ a fan issue also just throw a goood cfm flowin electric fan and nice shroud!!

[rwhite65]

Jester-
I was actually talking about the inside of the radiator. My old motor had a lot of corrosion on the inside of the coolant jackets from the previous California owner running straight water in it. I finally got tired of the cooling issues and took it to the radiator shop where they took it apart and cleaned it up just like new.

But Jester did make an excellent point. If you live anywhere like Illinois, driving threw the country for a summer here, them ole bugs outta the corn fields will fill the front of the radiators real quick.
Ryan

[Rev]

I think rodding out the internal passages of the radiator helped me more than anything else. My engine must have had a lot of junk left in the water jackets after the original rebuild. I actually had to do that rodding out procedure several times over the years before all the crud was gone. I think it cost me about $50 each time for the radiator shop with me doing the removal/reinstallation.

Rev

[~The Jester~]

You guys know about the "trick" to turn a crossflow into a 3X crossflow, right? Radiator shops have been doing it for the roundy-round guys for years. Works really well if you have cooling problems.

Basically they put 1 block off in each tank. This routes the coolant through the radiator THREE times before it returns to the block.

Didn't mean to hijack the thread, but this seemed like as good a place as any to put it.

[83mustanggttop]

the easiest way to tell if your rad. is clog is to let the temp get hot and then shut it off and feel the radiator all over with your hand and if there is any cold spots on it...if there is then you prolly got a clog...

[millrat86]

If it does have a clutch type fan I must agree w/Jester make sure it functions properly ie., you should feel slight resistance when you try to turn it by hand. Is the thermostat installed correctly? Is all the air worked out of the system? Do you have the correct rotation water pump? Did you have this problem before the water pump/thermostat change? Does the the lower radiator hose flatten out as it gets hot? I had to fabricate a spring for one of my lower hoses but that car only ran hot at highway speeds it sucked the lower hose flat. That cars radiator had restricted passages due to stop leak being added to correct pin holes from corrosion of the core.