A Heated Question

[Mikelb]

Ok, nevermind the pun in the subject... I know it was bad, but it was simply meant to catch your attention...
I've got a friend of mine who has a 95 Quest... the VG30E engine... this van overheated the other day on the freeway... now, I replaced the thermostat (no water seemed to leak out when I opened the thermostat housing, is that odd?)... I replaced the thermostat (that was definitely a problem)... and then I proceeded to refill the coolant system... with water for a test... No leaks, no pump noise, nothing... everything seemed fine until the van had run for a/b 15mins... the thermometer went all the way back up to H and there was no heat coming through the heater system... We tested the radiator... on the left side (looking at engine) we pulled the hose from the radiator, there was steam... I'm assuming this is the hot side...
We replaced that hose and went to the other side, we got nothing... I'm assuming this is the "cold" side... crazy thing was, I coud pop the radiator cap while the van was HOT... the cap was cold, no overflowing nothing...
I'm assuming there's no flow through the radiator... there are no holes in the radiator... no leaks anywhere... but no flow... I don't really know what to do other than flush the system (I intend on doing this anyway)... but I want to make sure the problem is corrected before spending the time/money to flush it... any ideas, and am I correct on the hot and cold side?

P.S.- The reservoir filled up when the van overheated on the Highway... it hasn't gone down since... no higher, no lower... even when we ran the van again a few times... this puzzles me...
but I'm pretty set on there being no flow through the radiator... b/c I just ran into that problem on my car...

[paul allain]

probably have a blown waterpump, no flow equals waterpump defective. or major blockage somewhere in the system.

[chubbybubba1]

I'd pull the radiator and take it to a shop and have them boil it out and test it. Or like the other poster, the waterpump. Or you have a pocket of air caught in the system now after your repair atempts. Air will overheat that system just as fast as a failed waterpump or blocked radiator passage.

[jiri41]

After replacing the thermostat the best thing to do is fill with water put the radiator cap and let the engine run until warm or thermostat to open let engine cool down and refill usually a lot more water will go in.