I've been following the other active Heating Issue thread and that has helped me be able to:
* Flush the core both ways with the garden hose
* Checked the carbon brushes on the pump motor
- I actually replaced these a couple of years ago so I suspected that again.
* Verify the pump is working when heat is called for
* see that water is flowing with the hoses disconnected ( output of the pump hose and top hose of the heater control valve ) and motor running.
* Confirmed fuses are okay

But it's still blowing cold (outside temp = 50 F and temp setting = 90 F) .

After having flushed the core, I would not think it was air lock in the core.

Are there any other things to try?
Like - can the output from the back of the block be plumbed straight in to the core to rule-out the valve?

Thanks

 

It can...but you'll be all-heat, all the time, that way....or not. Have you checked your coolant temp via OBDII? It is quite common for the T-Stat to stick open. When mine was doing it....the coolant was running about 150F and the heater was cold. I would think that I'd have at least luke-warm air from 150F water, but it was stone-cold. On the other hand, the T-stat was the first thing I changed, and the heater matrix may've been plugged with the little pellets I continue to flush out of at least once/year.

Regarding the valve, since you've managed to successfully run the engine with the pump outlet disconnected, and observe that the pump works, why not reconnect that and disconnect the valve outlet and have another go? Or the outlet hose from the heater core...if no flow there...work your way upstream with the valve a likely suspect.

 

Ok yes - OBD2 is reporting temps around 180. I'll have another look at those control valve hoses, etc.

 

Have you run the diagnostic on the heater?
If the control flaps are faulty, the hot air might not be being directed to any of the cabin outlets. Also, are your blower motors working?
Finally, the little "aspirator" may be covered in fluff and debris. It sucks air over a thermocouple to tell the system how warm it is in the cabin, and hence whether heating or cooling is required. If it thinks no heat is required, there wont be any.
Covered by the heating diagnostic, referred to elsewhere.

 

i must not have been wearing the right glasses when I checked the brushes before. So I checked again and found the motor was weak and sporadic. Opening it up found the brushes were worn down to nothing.

But now i have a situation where the PCB board holding the brass brush retaining frame has cracked and does not hold the brush frame solid.

I wire wrapped it up for temporary until i can get something better.

I am thinking of getting a new blank pcb board and making my own or just buying a used unit.

But the motor did run stronger with the repaired setup.

I think I also saw a post where someone just used a different motor entirely. I may go search that out again.

 

See reply # 2453

https://www.jaguarforums.com/forum/x...84298/page123/