Hi,
I have a 2004 xj8, had the classic passenger side blowing heat, Driver's side cold. So did my reading and performed the backflush by disconnecting hoses up front by the resovour. Used bottom hose to drain, top one to flush in to heater core. Had some of the little gel ***** and darker flakes come out, put about 30 gallons gallons through till all clear. Now when I got her running, think I did an ok job bleeding the system, there is no heat.
Feeling the aluminum lines and the hoses running into the firewall they are definatetly not hot, I would say barely warm. So what should I try next test wise or parts?
Thanks in advance.

I also played with all the modes, (defrost, upper vents, feet and recirculate) and it would switch between them all great if that has any bearing on anything. Thanks.

 

Is the aux pump running?

Try flushing the other way?

 

I guess I don't understand how this heater core works. In my mind, because it flushes fine both directions, it would not seem to be plugged to me. So if hot water was getting to the core, it would blow warm air somewhere into the cabin, feet or defrost, somewhere. Again the hoses to the firewall are not hot or even really warm at all, and the controls switch from floor, to vents, to defrost.
So does this auxiallary pump push the hot water to the heater core? Is it triggered at the correct temp or is there an additional "thermostat" that should be opening up to let the hot antifreeze flow to the core? Thanks

 

The easiest way to get the air out of the system is put the front tyres on ramps
This raises the resevour to be the highest point.

1. Fill the system and with the cap off turn on the ignition, and turn the heat to full
Do not crank or start the engine just have it on run. This turns on the aux heater pump and get the coolant moving

2. Leave the aux pump running for a few minutes. Any air will settle in the reservoir.

3. Replace the cap and start the engine and let the car warm up

4. Once you have the engine fan running stop, take the car off the ramps and let the engine cool

5. Once cool check the reservoir and top up as needed

Cheers
34by151

 

I agree. It sounds like you have an air lock or your aux pump isn't working but in case and for others, here are the procedure for backflushing (oddly enough, no specific procedure outlined for heater core) but it does mention to separate systems. I included the basic 4.2 Liter block diagram

 

[QUOTE=tnord;1074079]Hi,
Used bottom hose to drain, top one to flush in to heater core.


Could you fix this link please tnord? I'd be interested to see what you were pointing to

 

I am not sure how that link got in there. I was posted in another sub forum on this site and copied my comments over and that happened. Sorry

 

Thank you to all. I determined the aux pump was bad. Took it off and brought it to an auto electric motor repair shop in town. A set of new brushes and $20 later I had it back and in and I have heat!

But now when started the check engine light is on, was not on before. I jacked up the passenger side for the system air bleed, could that have caused it? I unhooked the battery, crossed the cables, and let it sit for about 20 minutes and reconnected, but engine light is still on. Any ideas?
Thanks

Next to tackle will be the parking brake light.

 

check all the items you disconnected to get to the aux pump and if all they fails get the codes read

Its also a good idea to get yourself a mongoose cable so you can read the codes yourself

Cheers
34by151