Can a waterpump be bad and NOT be leaking ??

[guido1]

I have a 1996 Infinity I30 that I have had since 2010 but it has been sitting unused since 2011. When I got it it had a crack in the top tank of the radiator that had been patched. It never ran hot. After a while the crack came back through the repair and it STILL did not overheat. I drove that car everywhere, with the cracked radiator and just refilled the fluid once every couple weeks as it would slowly steam off. I last drove it from Phoenix to Tampa with zero issues along the way. I parked it when I got there and then in late 2012 I towed it backto Arizona on a flatbed. I started it up periodically to keep it up but the battery eventually got a dead cel from sitting too long. Recently I started to make the necessary repairs it needed to get it on the road again. A new battery to get it started, but it wouldn't start, so I got a new fuel filter because the engine was not getting any gas. Then I took out the fuae pump and discovered the fuel line had come loose, so I reconnected it and put a new hose clamp onto it., sprayed the gauge float which was sticking and then it fired right up but started to overheat. so I figured the thermostat must be stuck. I got the new thermostat and also scrored a new radiator at the same time and put those in. The car started right up, stayed within the normal heat range for a while and then the gauge shot up all the way. Hmmm, I know this car will drive ten thousand miles with a cracked radiator and never overheat,and the thermostat is new. I checked for leaks and found none. What I need to know now is this, ..... CAN this type of waterpump fail without leaking ??? The car has never been driven hot and has never overheated on the road, so I am really doubting a cracked head gasket. I did notice a lot of old sludge in the cooling system hoses and the old radiator. Is it possible the water pump is CLOGGED UP ?? My next step is going to be putting the old radiator back into it, then knock the stat off of the old housing and put that back onto the engine so it will be free flowing and then FLUSH the hell out of the cooling system..... a Few times, then when it is all cleared out, put the new radiator and new thermostat back into it and see what happens.

Yes, the cooling fans both work and they come on at the right time. I also noticed both radiator hoses were tight with excessive pressure inside when it was all heated up.

Anyway, really long post but the main question is just whether or not this type of waterpump can fail without leaking or if it is possible for it to be clogged and have a blocked passage or something. Thanks in advance.

[Maxcruiser]

The weep hole could be plugged up with grease/gunk.
If your oil seems like syrup it could be antifreeze leaking into your oil through the pump.

[guido1]

No Water in the oil, No oil in the water. Thinking about air pockets blocking up the flow, but not very convinced on that.