I'm almost 83 years of age and have a 280Z with stopped heater core. Is there any way to get this opened up without removing and replacing it? If not can someone tell me how to accomplish the removal and replacement of it? A friend (Z mechanic) has back flushed it for me but tells me he gets only a trickle of water to pass thru it. He doesn't have the time to do the job as he is still working for Nissan and stays real busy. Thanks. Hisson0712

Hey there Hisson0712. Good on you for driving a Zed at 83.

Sounds like a heater water valve may be jammed partly shut.

I had the same issue, deleted the valve and the flow was restored.

I yanked my valve and cleaned it while i had my dash apart, it was also stuck shut. the valves are really expensive to replace but i think you could fix it like this:

-disconnect the 2 hoses that pass thru the firewall at the firewall, the firewall pass thru tubes are only inches from the valve. your almost guaranteed to make a mess if your coolant is full

-with the coolant out of the valve squirt in some wd-40 and let it sit a few minutes. That trickle should be enough to get the coolant at least lower than the valve

-work the valve arm directly, don't use your heater controls if they are stiff or you might break something

-it should break free and start acting like a valve again. If it doesn't try yanking the valve and cleaning it in the sink like i did.

You wont need to pull the whole heater core or anything but the valve is pretty tight in there and likely attached to rotted hoses which will disintegrate on contact which is why i suggested trying the above method first. No guarantees, good luck

The heater core is a big job. I restored mine when I had the dash out. At that point it was an easy job and it worked out real nice. I also replaced the control valve because mine was stuck SOLID. The one that came wasn't quite right but I was able to swap the new parts onto my old bracket and presto, no leaks and works smooth. With that said you will have to contort your body to work under there. Good Luck!

Control Valves

http://www.thezstore.com/page/TZS/CTGY/SHC03

I hope i will be driving my Z when 83, respects for that!