overheating....

im running a 94 7.3T
new water pump, new radiator, new thermostat and new clutch fan.
drove it for about an hour lastnight, and the stock gauge went to the L.
then i started to loose power. not good.
i got her home. and checked on it this morning.
no water in the oil, water at maximum.
im only running water for now to make sure things were good.
i noticed that my waterpump pulley has about .010" of play in it.
bolts are tight.
gotta be the bearings in the pump??

You should have a very small amount of play in the shaft of the water pump. Like 1/16 or 1/8 of an inch, some thing like that. What you don't want to see is coolant coming from the weep hole in the water pump. Did you check/replace your radiator cap? 13lb I believe is the correct pressure. When I got my truck about 3 months ago I pulled the block plugs and drained them and a bunch of crap came out of the block. You could have a bunch of crap in there helping with the over heat of the engine.

Why did you replace all those items?
Was it overheating before replacement?
Did you use the Ford thermostat?
If your gage was only at the L it is still in operating range.
When they overheat the factory gage will go off scale to the pin.
If it didn't boil out it could not have been truly overheated.
Is your air conditioning condenser restricted?
what was ambient temperature?
Were you driving slowly with a tailwind?

My factory gage will hit the L when idling for more than a few minutes.
I also have an aftermarket gage and L on mine is around 230F hot but not scary.

Your loss of power may be cause rather than effect

i replaced these items before i did the engine swap.
i absolutely hate having cooling issues.
i had some (donkey) helping me when i did the swap, i asked him to take the old clutch fan off,
however, this "certified" mechanic, went the wrong way and killed the pump and the clutch.
i did not use a ford t-stat, got one from napa.
outside temp was 80 degrees.
it ran normal this morning.
driving ~ 50 mph
radiator cap is new
may be time for new injectors and IP but i dont have the coin for them yet.

May not be the issue, but everything that I have read said to only use the correct the Motorcraft Thermostat. All the others do not flow enough/correctly to cool correctly.

Yep, there's the first mistake. You should use ONLY the Motorcraft thermostat. There may be others which fit, some which look identical, some which will even work for a short time. But there is apparently only one which will work properly.

You've got to pull that imposter thermostat out and replace it with a Motorcraft model.

The opening in the motorcraft thermostat is much larger than a typical aftermarket version. I bet your problem lies here. Also, the motorcraft doesn't open until 190. That is very close to the boiling point of pure water...just sayin. My truck when towing wil run 225 to 230.

get the right stat, and do you ever hear the fan?

the "m" on my truck is 270 deg, so really do need some real numbers.

cpdenton said:

The opening in the motorcraft thermostat is much larger than a typical aftermarket version. I bet your problem lies here. Also, the motorcraft doesn't open until 190. That is very close to the boiling point of pure water...just sayin. My truck when towing wil run 225 to 230.

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vboiling point under no pressure. The boiling is point it raised when the systme is under pressure.
around 245F is boiling point in a 14lb system.

Yeah I know, there is a lot of controversy about different t'stats, but the correct one is the Motorcraft R1049 IIRC. The copper slug on the Motorcraft is designed to plug off the bypass so the coolant does not circulate within the head, but goes thru the WP and radiator when the coolant temp reaches 190*F for maximum cooling.

1st pic shows the bypass hole in the center of the t'stat mount.

2nd is the correct t'stat.

3rd shows the copper slug that blocks off the bypass.

Well you have been told. Now some info on the correct motorcraft stat. They BEGIN to open at 192 degrees and are fully open at 212 degrees. Many aftermarket stats will fit and even look the same but they are fake ass poor quality reproductions and can not pass enough coolant to keep us running correctly. Now about this new fan clutch and radiator. What and where did you get the clutch and radiator. Just cause they are new does not mean they can cool this engine. We can't cool with a 3 row radiator no matter what the fools selling them tell you. This applies to the copper brass types. The better all aluminum radiators with the welded top and bottoms will out cool most anything. I'm no fan of the plastic top and bottom radiators either. Seems only the factory fan clutch works wel. Aftermaket ones just are not up to the task of our engines. No matter what fan clutch you have they can be modified. Remove the fan and remove the flat thermostatic spring that opens and closes the valve in the clutch. Straighten out the bend and rebend it about 1/4 inch closer to the short end. Install with RTV and run like the wind. What this does is causes the fan to lock up around 200 degrees. Maybe a little higher but its way better than the 235 to 250 degrees most of even the unmodified factory fan clutches are.

Right on guys! ill change that t-stat.
I was pretty busy yesterday.
but I have my hood all fab'd up and ready for filler!

IDIoit said:

Right on guys! ill change that t-stat.
I was pretty busy yesterday.
but I have my hood all fab'd up and ready for filler!

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Forget the hood...mind you it's neat....but whats scoop on rat rod in background...do tell inquiring minds wanna know

It's not a ratrod.
It's a hotrod!
A Lill 30 olds 5 window I built 8 years ago.
I ran a consistent 13-13.4 ET in the 1/4 mile.
On a stock th350.
Powered by a Pontiac 400"
Now has a st-10 4 speed.
I need to go through the engine. Do some upgrades.
She's a fun Lill *******.
I've been doing customs for 20 years, but these 7.3s have me captivated