weird cooling problems *help*

[clovers525e]

so, my friends just baught my brothers 240 and he is having some weird problems out of it. its a 90 s13 with a 95 s14 motor. when he first got it it didnt seem to have too many issues overheating. of coarse we wouldnt know since the temp gauge was never wired up corectly, along with the tps and a bunch of other things but thats besides the point. he drove it about 45 minutes the other day and called me saying it wouldnt hold an idle the water pump was smoking and sizzling. two days after he got it, it started taking alot of water, he would fill up the reserve tank and it would be empty the next day or after he drove it or not, didnt make a difference. there was a little water on the ground but not as much as it was loosing. we replaced the water pump and thermostat the other day because what water was leaking out seemed to be comming from around the main pully. now when he drived it a little the overflow tank bubbles alot the top of the radiator is really really hot, the center is not even luke warm. the exhaust gas doesnt seem to be any abnormal color (ie white, whitish blue, pink, whatever) so, thats about it. where going to replace the lower radiator hose because there might be a coolant leak there (probably not or if at all a very small one) and where going to install my water temp gauge to see if that gives any help too but if anyone has any ideas that would be fantastic. should we pressure test the coolant system? i'm going to give him a new rad cap i have off my s14 too.

[pr240sx]

take out the thermostat and flush the system.Also, check for any leaks around the heater, if in doubt, bypass it.

[clovers525e]

bypass?

[pr240sx]

bypass the heaterAlso remove the thermostat to eliminate the possibility of a blocked system or faulty thermo or even air bubbles in the system.

[clovers525e]

i think i'll check the fsm to see how to bleed the coolant system, replace that hose and see if that fixes it. my dad was saying there was probably a leak in the block somewhere and that was forcing air into the coolant system. i guess if that was the case the head gasket would be where to look but i thought there would always be coolant being burn if there was a leak in the block and would result in white smoke. the thermostat should be fine since we just replaced it. and there isnt any coolant on the floorboard so i dont think the heater is the problem.

[tonynalli]

get a block tester, the only real way to check to see if you have a blow headgasket is by using that. if you dont kno what it is, flag down your snap-on tool truck and he will tell/sell one to you.