andymuffins

Hey guys, thanks for the help inadvance. I just bought a 95 GT 5-speed vert less than a month ago. I had to put a radiator (AutoZone $119)on it as soon as I bought it because the one on it had a flange broken from a wreck. So I bolted it in and drove it home with out fans or overflow, everything was hunky dory, even drove it around town like that for a few weeks.
Next thing you know, I bolt everything back in, get it out of the body shop, put some water in the overflow and head to the interstate.
It started to run a little hot on the interstate, over the course of the weekend it progressively gets worse, till on my way back home it went past the normal indicator into the red area, I cut it off, let it cool, and then headed to the nearest Autozone thinking it was a stuck thermostat. Dropped a 180 degree thermo in the parking lot, filled it back up with water, burped it as bestI couldand took off.
It was ok for about 20-30 minutes going about 70mph, then it crept back up progressively again. Eventually getting real close to red.
And heres the wierd thing (I thought), running the heater on full blast did not matter at all, It just didn't matter. After I got home, I noticed a hissing sound, the hole on top of the water pump, it was pushing out hot air.
The temp outside never got over 85 this weekend, on the way home it was about 75. There is a set of aftermarket pulleys on it. Other than that and some headers the car is stock that I know of.
I checked the water level several several times, it need a little maybe, maybe a quart but that's it. Nothing crazy that wouldn't have boiled off.

Both the oil and the water look clear of alien objects as well,other than a normal amount of rust in the water.

This isn't my first stang, and I'm fairly astute with the 5.0L, any help would be greatly appreciated?

Andy

mattdel

minor, gradual obstruction of flow.

hows the heater core?

andymuffins

Heater core seems fine, I could doa flush tomorrow and see what happend. The air coming out of the heater core seemed HOT and stayed that way. Power has remained constant in the car, good linear power, no power loss that I've noticed.
Some people said that the blades on the waterpump impeller could be corroded or rusted and could be slowing down the flow. Also, I the pressure in the hoses seem good and hot to the touch.

mattdel

pressure is a byproduct of heat.
not a bad idea to try and flush the heater core, see what happens.
also, maybe bypass it for a day and drive the car around, see what happens.

also, it is entirely possible for the impeller blades to be completely missing & corroded away from the water pump, though i've only seen that one time, out of hundreds of water pump jobs.

andymuffins

OK, Pulled all the hoses off and I flushed everything including the heater core, pulled the thermostat out and drilled an 1/8in hole in it so it would burp better. Sealed everything back up, filled all the hoses and radiator up with water and started the car.
While it was running I squeezed the top hose and noticed a steady dribble coming out the bottom of the water pump.
Thinking it might be impeller blade problem I went ahead and pulled the water pump off,the blades look 100% great. On the other hand, it looks like the leak/pressure hole at the bottom of the pump could possibly have been leaking at least a couple of days from the rust marks.
It doesn't explain why it was holding pressure before, operationally the water pump seemed fine. And driving it around the previous days it had not leaked any significant amount of water.

What do you think guys? Could this have been a compound problem with the water pump failing, minor obstruction somewhere, and air pockets? Thanks in advance.

Already Matt you have been most helpful.

Andy

mattdel

if you squeezed a hose and it leaked from that hole, its bad.

BiggusJimbus

You replaced the radiator... Did you put a new cap on it?

I've seen MANY overheating problems come from caps that leak or just don't hold the pressure.

Often a cheap fix.

andymuffins

Right, as I said before, the car has good pressure, there is noway I can squeeze the hose more than a half inch after it builds.

Right Matt, For sure I know the WP is bad, but is that the culprit of all my past problems as well??

Thanks again.

Andy

mattdel

how much testing/checking of the fan have you done?

andymuffins

The fan was working fine before, after I installed the thermo I noticed that it did not kick on when it should have, I might have burnt a fuse or relay because it was running so much going down the highway. There is no reason a fan should kick on when you are taveling 60+mph. I will diagnose the fan after I install the new WP after 4pm.
Is there a good thread available for fan diagnosis problems?

Andy