I have a 2003 XJ8 with a bit over 30,000 miles. Although I live in FL the need for a heater is limited I have a wife, anything below 70 degrees is considered cold to her.

When I place the climate control gauge on the dash to Auto and set the temp high like 80 degrees we don't seem to be getting heat coming from the system only cold.

I also have tried the seat heaters and with the temp set high they don't seem to become warm on either driver or passenger front seats. Any ideas would be appreciated.

 

Sounds like another blocked heater matrix. This is a common fault on these cars apparently, although not happened yet on mine, thank goodness, as it's cold here, right now

 

The seat heaters are normally very slow to heat up.

Do the lights come on the switches? Three lights for max heat.

Try leaving heaters on for 20 mins? Are both seats not heating up?

WRT the heater is it blowing air ie is your blower working?

Does it heat up when not on Auto?

 

The seat warmer seems to be working, I was being impatient. The actual heater I had used by leaving the climate control in auto, then raised the temp reading to 80 degrees. as I increaase the temp. the fan blows harder but not with warm air.

i didnt try it by turning off the auto button, i assumed maybe incorrectly the auto button on and increasing the temo was the correct way.

 

You are operating correctly. Auto or manual makes no difference when you are calling for heat. The temp control should be commanding warm air or hot air
depending on the differential over ambient.
Fraser hinted at the probable cause. Clogged heater core. Back flushing sometimes improves it, but the real cure is replacement.
Suggest getting some estimates from dealerships and independent shops.
Then get it fixed to keep wife happy...

 

also check heater auxiliary coolant pump if equipped,,

 

Yes, another thing to fail, but almost never gets a mention. I think the heater matrix is probably the cause, but this little pump probably needs checking out; certainly on the X308s failure has been recorded, but it may be a different design.

 

I have the same problem.
1. Where is the aux pump?
2. how is the core removed? Does that take a buck of dash out?

3. I also understand that the dccv fails often. Can that be accessed internally?