Cooling system information

[RogerZ]

On my 81 turbo there is a spring loaded check valve which diverts coolant back to pump suction when the heater is not needed and no flow thru the core. Manual climate control.

On my 83 N/A with the fancy digital control this check valve is not there and it appears that coolant always flows through the heater core and there is some sort of flap in the dash which diverts air flow cause I am either hot or cold no in between (separate issue of course)

On my 83 turbo with manual climate control there is not this check valve seems like the same setup as my 83 na. This car has a digital dash but manual climate unit (did someone substitute). Reason I ask is that the 83 turbo blew the head gasket between 7 & 8 which is where the coolant comes out for the heater core and I was wondering if because there was no return of coolant at that point caused local over heating and gasket failure. Appreciate any enlightment from those with more Zxperience.

[whew41]

Roger,

I have a simliar issue on my 83 280ZX. No matter when I set the air control on all I get is air through the floor outlets only. Last Night I took the air control assembly to see if anything had come loose, but I did not see anything. So now I have to located the vaccum device that controls the dampers for the air flow. If I come up with a solution I will post it on here for you. UNLESS someone else on here as any good ideas for both of us