Not much heat even when temps normal and heater on full
 

It's warm yes but not roasting, I thought maybe a duff stat but then thought temp wouldn't sit at 9'o'clock. Think I'll need to change the pollen filter, but that's bug ger all to with the heat.....anyone know

You need a fuel burning heater... Brilliant innit.... :D
...

Wrong thought Stewart! :D The gauge will reach the nine o'clock position at a coolant temperature of only 75 degrees. But watch what happens when the car is at cruising speed for a sustained period; does the gauge drop below nine o'clock?

Simon

Don't know, haven't been on motorways yet......but what's the problem with the lack of heat despite being up full

Either the heater matrix is partially silted up (poor flow) or the thermostat has suffered the common fate (premature opening and cool running). Maybe both. I'd suggest running the Trip Screen Diagnostics to see what temperature the engine actually reaches. It may be lower than you think. As indicated, the temperature gauge is of no use for showing the running temperature.

Diagnostic Mode; http://the75andztclub.co.uk/forum/sh...d.php?p=735128

TC

Im in the same boat! I remember last winter how its nearly hot enough to burn your face on max, but recently, not so...

Have got one of the inline stats here so it gets it going for now till i can do the proper job.

Moved to technical help forum

As T-cut suggested, run the diagnostic mode on your dashboard to check your actual coolant temperature before deciding that it's a duff thermostat.

Press and hold the trip-reset button until it displays "test".
Press the button repeatedly until it displays "19" then wait.
It should begin alternating between "on" and "off".
When it displays "off" press it again and "test" will return.
Now press it repeatedly until "7" is displayed.
A moment later your actual coolant temperature will be displayed and will continue to do so until you either a) press and hold the trip-reset button or b) you turn the ignition off.

The temperature should continue to rise until the thermostat opens, then should drop as cool coolant begins to circulate, then begin to rise again. At some point it should begin fluctuating between your upper and lower averages. I don't know about the diesels but my ZT-T 190 typically fluctuates between 92℃ and 98℃ around town but can be as low as 88℃ and occasionally hits 100℃, at which point the fan comes on and it drops again quite quickly.

I'm sure if you post up your actual temperatures then someone can advise as to whether that sounds correct for a working 'stat on your car.

If that checks out ok then you will probably be looking at a fouled up heater matrix.