Overheating issue(s)

[Bonkers]

About a month ago I went out for a cruise and the Viper
just decided that was the day to overheat. After talking
to the gurus and tinkering about a bit, the consenous was
a bad water pump. I replaced the pump but nothing has
changed.

She's a 99 GTS with basic mods. When I let it idle it
warms up very slowly, almost like normal, but then
suddenly spikes to 245d (where it holds until I drive.)
The water pump gets scalding hot, but the hoses only
manage luke warm, and there is no heat inside. I also
have no pressure to the heater core until the coolant
begins to expand. My friend is convinced its a bad
head/gasket since it spews large amounts of cold c
oolant everywhere when you pop the cap off.

System is properly bled and the fan works like normal.
The OBD reads same as temp gauge.

So is it possible I scored a bad new pump, or did I s
omehow manage to warp the head?... or something
else entirely?

Any thoughts?

 

[Camfab]

Is the thermostat working?

 

[daveg]

^^^^^ If the Radiator and hoses are cold, check T-Stat. This providing the system is bled!

 

[AJ02]

Even if the thermostat were stuck closed, there should be heat inside the car, no? It was my understanding that when the stat is closed, it still circulates coolant through the heater core, given the water valve is in the open position. It gradually opens and sends coolant to the rad, as well as the heater core.

 

[Bonkers]

I have not checked the tstat yet but will when
i get back into town. The issue i cannot get over
is there being no coolant flow to the heater (we
pulled the hose off to be sure.) I can understand
it not being hot coolant, but how can a stuck
thermostat prevent all coolant from flowing to the
heater? (not saying it cant, just saying i dont
understand...)

 

[AJ02]

You got me on that one, boss. If the water pump impeller is turning, you should have somewhat pressurized coolant flowing to the heater valve whether or not the thermostat is open. Not trying to be a ****, but is there any way you could have gotten the belt on the water pump pulley backwards?? I know that's a stretch, but possible.

 

[ViperJohn]

Brian,

You mention that at idle it spike to 245 degrees until you start to drive. It's been pretty cold outside lately, when you are moving, does the temperature go back down to normal range? Have you confirmed that the valve to allow hot coolant to the heat core is opening and closing properly? You can see it move when you move dial from cold to hot...

I still think based on your description that you have air in the system.

 

[ROCKET62]

Also worth checking the lower hose to make sure the spring inside has not moved allowing the hose to collapse.