I would guess it's the thermostat being bad.

 

No, this isn't an airlock problem. It is a D40 problem. Not sure if it got better with the 190.

Under 1500 rpm the heater does not get warm. Full stop. In the cold weather you could leave it ticking over for hours without much heat. As you say, if you drive in town on a cold day you will get cold.

What are your options?
1 ignore the climate control and put the heater on high helps sometimes
2 Drop a cog in town to keep the revs above 1500
3 Remove the enormous cooling fan
4 Switch on your heated seats, if not fitted you can buy a kit for £70
5 Wear a big coat and gloves
6 Don't drive in town

 

No, this isn't an airlock problem. It is a D40 problem. Not sure if it got better with the 190.

Under 1500 rpm the heater does not get warm. Full stop. In the cold weather you could leave it ticking over for hours without much heat. As you say, if you drive in town on a cold day you will get cold.

What are your options?
1 ignore the climate control and put the heater on high helps sometimes
2 Drop a cog in town to keep the revs above 1500
3 Remove the enormous cooling fan
4 Switch on your heated seats, if not fitted you can buy a kit for £70
5 Wear a big coat and gloves
6 Don't drive in town

Ah no mate, I appreciate the response, but something has definitely gone awry with the heater. Usually, on a very cold night I could go out, start the engine and put the heater to high and the fan to medium about 10mins before I needed to drive. You'd get into a reasonably comfortable cabin and, once on the road, the temperature would come up fully and you could knock the temp setting back a little. While I do know that slow driving or stopping would see the cabin temperature dip somewhat (I've never used the climate control once in 100k miles!) it would never revert back to a cold air situation, which is what is happening now despite the temp setting being left at maximum.


Pollen filters were changed before the "summer" and the blower is blowing.

 

Ok, but the symptoms you describe are pretty much standard for a D40 in the winter.

 

I've had the same vehicle since 2011 mate, there is something different about it lately and we ain't even down to single digit day temps yet!

I'm going to check the heater matrix for a problem/blockage tomorrow and if that checks out I'll change the stat at the next service.

 

Just bleed the coolant. It is possible you have an air lock. There is a small bleed cap on the junction of pipework on the bulkhead (engine side). With the engine cold, leave the cap off the expansion tank and the bleed cap. Run the engine at idle and it should expel any air held in the system

 

Would using the warm up button (higher engine speed ) help?

What is that for any way I guess for warming it up b4 you drive on cold days like clearing frost off the window?

 

I have used that button, but I'm not a fan of it when the engine is stone cold. I was always of the opinion that the feature had more to do with feeding amps to the battery while something was drawing lots of power from it, a winch for example.

@lookskyward1
Appreciate the guidance mate, I'll certainly try that before the stat is changed. I have a stat in stock now, and a waterpump on the way from Milner's (along with a brace of other bits I felt were quite handy to have on the shelf). I went so far as to order a spare SQV!

I now have that valve, the waterpump, a single mass flywheel and clutch kit and a halfshaft bearing kit in my spares box.

I also have a few non-essential items to bolt on over the next few weeks, including a curved 52" light bar and snorkel.

 

park nose up and run it with the rad cap off I had this exact issue when I first got mine, make the rad the highest point of the system nature will do the rest, unless you have topped up with a non OAT antifreeze that will cause some gelling and will need a full flush/clean.