i ve change thermostat got new radiator fluid(its full) temperature is on half fan working, and still have no heating, only sometimes got little bit warm. maybe someone got any idea what i can check or do next to not replace heating core?

 

Check the heater auxilliary pump for operation. Backflush the core and make sure it "looks" like reasonable flow. Make sure someone has not reversed the heater valve hoses.

 

Hi
Your heating system hoses are probably clogged. I had the same problem with no heat, just had it fixed about a week ago.

The Coolant Expansion Tank had to be removed to get access to the heating hoses connected to the Heater Water Valve. Removed hose from Water Valve and blew air to clear any clogs, then flushed water through it.

The process had to be done twice before the heat stayed on. Also had to clean out the hose from the Heater Water Valve to Aux Electric Coolant (Heater) Pump (it was also clogged).

I also had to replaced the Aux Electric Heater Pump (the dioide in the pump motor died) with a used heater pump from an online source.
The purpose of the heater pump is to provide heat when the engine is just idling.

Jim Lombardi

 

Here is a JPEG file showing the Heating System Components and Schematic - both have a Parts List corresponding to the 2 illustrations - Use your internet browser Zoom feature to increase it to 150% to be able to view parts lists then use print preview with full width option for a reilly large view):

http://i1178.photobucket.com/albums/...Components.jpg

Item# 1 assembly pump - water is the Auxillary Electric Heater Pump. Items 7 and 9 are the non-return valves.

Look at one-way hose valves (no return valves) in the Schematic (they also can be clogged).

Jim Lombardi

 

thank You all ill try check Sunday, now i got 3 day heavy rain ,

 

I am having the same problem with my 2000xj8. The pump is good, a new ( used )valve was installed, the heater cores were flushed and have good flow. Now what. The top hose going into/from the valve from the firewall area does not get warm. I am looking at the schematic ( http://i1178.photobucket.com/albums/x367/Jim0206/XJX308HeatingComponents.jpg )and the line schematic shows the hose from the bottom of the valve going to the pump. My top hose goes to the pump. Could I have gotten these mixed up. Seems difficult to do as they are all formed hoses and they only want to fit one way. Is there a better "drawn" schematic for the water lines and valves??

 

I just went out and swapped the hoses on the front area of the valve. They do fit even thought they are preformed hoses. Still no heat.

 

Hi
Not sure this will help. I copied the diagrams from the JEPC (Jaguar Electronic Parts Catalog) and the JTIS for the Heating Components (I did my best to try to relate for components in each diagram to each other):

https://www.dropbox.com/s/822tft6cpd...iagrams%20.jpg

Here is another forum no heat thread I recently posted (look at post# 4) in the following thread:
https://www.jaguarforums.com/forum/x...8-xj8-l-87931/

Jim Lombardi

 

I was right. The hoses were in the wrong place. The mechnic who changed the tranny had to fix the valveand put the hoses on backwards. After I swapped the hoses and did a test run I pulled the rear hoses off. Clear water ran out, no antifreeze???? I pulled off the last hose that runs to the other side of the engine and blew through it. No problem. I put it back together and took it for a run. First mile I had warm air then it went down to cool air. In the next mile it went to hot air. I don't know why but I hope it keeps working like that. At least I don't have to worry about my heater coils not having antifreeze in them. Could there have been an air lock in the hoses?

 

It's not unusual to get air in the system after draining and refilling. I think the secret is to allow the little jiggle valve in the thermostat to bleed the air through before topping off and replacing the cap.