Have not heat on 2000 XK8


OK this is what I did. It is getting cold in Carolina any help would be great. Following is what I did to get heat.

1.Back flushed the heater core again with home water hose. (60 psi)
2.Started engine with heater valve control power disconnected. This was maintained during all tests.
a.Had flow coming out or hose that leads to the left side of core (when looking from front). Kept water tank full during this task.
b.Connected supply hose to core.
c.Water flow from outlet side of heater core.
3.Check air coming out of air out lets. Air was warm. Kept water tank full during tests.
4.Connected hose to new check valve and hose assembly.
a.Started engine and checked for warm air coming out of vents. No warm air.
b.Checked inlet and outlet tube on heater core both cool no heat.
5.Started engine with return hose from heater core removed.
a.Applied water pressure to return hose with check valve. Water would not enter back into engine. (Question should it?)


Thanks,
Becky

 

I'm sure you have heater control head set to hot. Control head may not be working, it may be thinking it is set to cold. Just a thought. Would need scan tool to check that.

 

Becky, Did you check the operation of the heater pump, down by the transmission.


Wayne

 

Good suggestion Wayne. There's a single fuse that controls that pump as well. If it's the pump or the fuse, you will get a little bit of heat when driving as there's more coolant flowing through the whole system when the engine is revving. I know, that happened to me a couple of years ago. Easy fix!

 

Here is a another list of what I did.

a. Install new heater pump and it is running. Installed new heater control valve.
b. Removed supply hose to heater core. Had flow coming out or hose that leads to the left side of core (when looking from front). Kept water tank full during this task.
c. Connected hose back to supply side of core.
d. Removed hose from return side of heater core. Water flow from outlet side of heater core.
e. Connected return hose to new check valve and hose assembly going to engine.
f. Started engine and checked for warm air coming out of vents. No warm air.
g. Started engine with return hose from heater core removed. Have full flow and warm air from vents.
h. Applied water pressure to return hose with check valve going to engine.
i. Water would not enter back into engine. (Question should it?)

Becky

 

Becky, Sorry you are having so much trouble, been very cold for us lately.
Not an expect on the heating system, but do know that one way valves are installed in a few places in the water circulation system.


Wayne

 

This shows direction of flow, where non-return valves are etc.
Might help ??

 

New check valve defective or labelled backwards?

 

thermostat backwards? also see if the hoses going thru the firewall look compressed.. if so im guessing its a bad auxilary heat pump.

 

Found new thermostat installed backwards. Now have heat!


Becky

 

check to see if you put t stat in backwards