I've had a good old search and cant find anything relating to this.

My face vents don't blow hot. If I cycle it between hot and cold, it does get VERY cold, but only lukewarm out the face vents.
The footwell vents happily go from very cold to very hot. So the DCCV is ok I believe, it was already replaced not long ago. I cant find a clear indication of what the blend doors do regarding temperature. So that would be a great help if anything has the details on that.

On a side note does anyone know what the blend door and actuator on the far left of the car behind the glove box controls? The one in this video:
Any ideas would be greatly appreciated,
Tom

 

I should also point out, this was came about after sending my car in for an aircon recharge, ofcourse it was summer and hot so i didnt realise i dont get hot air through the face vents anymore

 

What happens if you increase the temperature setting until HI is displayed, and then press the button to send all air to the dash vents? Selecting HI puts the system in manual mode, and bypasses many (but not all) of the automatic inputs.

Not sure how true this may be, but it's been my understanding that when in automatic mode, the system works in a very genteel fashion. In other words, by design, it won't roast your face with hot air unless you go to manual mode.

 

Thanks for getting in touch. It gets to a lukewarm temperature but no more.

Before it would get rather hot, keeping it at 21.5 was always the perfect temperature, now that feels cold.

 

Not sure what to tell ya. I played around with my '02 yesterday. With manual HI selected, the hottest I could get from the dash vents was 110F. Switching back to auto and selecting 85F (the highest auto setting) made no difference. Manually directing the output to the floor didn't make much difference, either. The airflow at the floor was too diffused to get a good reading with the little pocket thermometer I have.

Did you ever tried selecting manual HI? You haven't really said one way or the other. Manual mode is a big help when troubleshooting. Could be your cabin temp sensor is drifting out of range, as you mentioned setting 21.5C always seemed good but now feels cold.

You could also try switching off the AC for comparison. Under most conditions, it runs even on cold days to dry the cabin air. Just a guess but maybe before the recharge, the AC wasn't working at full capacity so 21.5C felt okay. But now with the previously missing cooling side of the equation, that same setting feels cool. There may not really be anything wrong with the HVAC now, but if feels different (cooler) with the AC working and lowering the humidity. Switch off the AC and see if 21.5C feels about right again. If so, it's a perception issue, not an actual fault.

Also, what is your driving pattern? From my experience, the heater is very slow to crank out the heat after a cold start. I have to drive at least 10 minutes at higher speeds before it really feels warm. (This is in marked contrast to my old pickup, which will roast you out of the cab by the end of the driveway.) Heater performance is only fair at low engine RPM, too. So if you're just putzing around town, you may not be getting much heat output. Which engine do you have? On V8 models, heater performance at low RPM is so poor that Jaguar added an auxiliary coolant pump primarily for this reason. If you have a V8, there's no indication of a failed aux pump except for poor heater output at lower speeds. On my V6, it also suffers from poor heater performance at low RPM. I can tell when the coolant level is low because the heater cools off a little when I come to a stop, and picks back up again when I get going.

 

It is a strange one, its never acted up like this before, I wont rule out the idea that in in my head, but front passengers do now complain in the front if its anything below 24v.
Oh yes, sorry I didn't make it clear, I tried the Hi setting on manual mode to the face, you do make a point about the recharge, although previous recharges never had an impact like this before though, so I was wondering if there was an issue with a blend door somewhere, unfortunately I don't know well enough the workings of the doors in regards to whether they just control the flow of air, or temperature as well. I've always had the AC on constantly, with it off it does start to blow warmer, but I imagine that's due to the lack of AC more than anything? What makes me wonder particularly, is that when its a colder day (say 12) and the temp is set to anything below 24 it blows cold or cool air, when it used to blow warm and I would expect it to with the temperature readings.

Its the 3.0litre model and I do drive to enjoy it if you get my drift, no point having a decent size engine and not enjoying it!
I hadn't thought of checking the coolant level but I have had to top it up on occasion so that sounds like a good call and Ill check that next Thumbs up

 

Right, I've made some progress! So I decided to repair the blend motor arm behind the glove box, I had to glue the bit of door where it holds, as in the video. I then opened the motor cleaned the contacts and reset the arm position as it had travelled too far. I tested it and it ran well for a while, repeatedly changing the settings on the Climate control. But then suddenly it travelled too far and promptly broke off the glue repair.

Is a Blend motor traveling too far as issue with the motor itself or is it an issue elsewhere causing it to do it?

 

I'm not sure what to tell you about that door and actuator. The music in that video sure is irritating, though. I don't mean the choice of music itself, just its presence, as it interferes with the narration.

i think that is the fresh/recirculation door. I don't believe it should have much (if any) effect on heating once the cabin temperature is stabilized. Recirc helps speed up initial cooling on a hot day, but I'm not seeing it do anything to the heat from the vents.

I wonder if something is blocking the door from traveling fully in both directions. I wonder if that is why the linkage broke.

Back to the apparent low heat from the vents. Playing around on my car, I've just found the driver's side is about 15F cooler than the passenger's side. Unless there's a clog in the heater core, the problem is almost certainly that side of the DCCV not opening fully. (I have a new one on order.) Have you checked the dash vent temperature on both sides? I'd highly suggest using a little pocket thermometer for an objective reading, versus a subjective sense of how the air feels on your hand.

The DCCV has a very high failure rate, so don't assume it's good simply because it is fairly new. Post #2 here describes how to test it:

https://www.jaguarforums.com/forum/s...ol-how-185002/

That only tests if the valves fully close. I never thought how to test if they fully open, as that usually isn't much of a problem, but it could be here. But first, I would test that both sides do fully close. It's easy to do, and if the test reveals a valve not fully closing, it may also not be opening fully. Compare duct temps on both sides, as it is not likely for both valves to fail together at the same percentage of travel.

Read through post #6 at that.guide, too. Specifically, check that the coolant temperature is approximately 200F at the DDCV. If low, that would reduce the heater output.