Poor heater

[loyalduke]

After all the problems with overheating resolved I now find that the heater is only throwing out luke warm air :roll:

The temp guage is rock steady in the middle and yet the air coming throught the heater vents is not hot enough to take the chill off thecabin and its not even relly cold yet :? .

Any ideas :idea:

[Mark2Disco]

i  flushed the heater matrix by taking pipes off under bonnet and running hose pipe through them for about ten minutes each way
its pippping hot now
hope this helps

[Range Rover Blues]

You have got a thermostat in there havn't you?

[loyalduke]

You have got a thermostat in there havn't you?

It was in and out during the saga but it is back in :roll:

[Range Rover Blues]

Then possibly an air lock, filth in the heater, a collapsed hose.  Does it get better when at speed, the diesel does suffer over-cooling at idle.

[muddyjames]

Mine used to be luke warm when going about town and then get very warm along the motorway. I changed the water stat and all was fine again.

[Graham2]

I'd back flush the heater matrix. You'd be amazed at the crud that builds up in them. Mine was throwing out no heat at all, even with a hot engine. After I'd done it, I couldn't hold my hand over the air vents! Sticking a new thermostat in every couple of years is a good idea too, as they degrade over time, causing them to stick open a bit (or a lot) resulting in the engine taking longer to reach operating temperature.

[muddyjames]

how do you back flush the heater matrix? I went through a ford and got the water coming in through the air vents but im guessing thats not back flushing it!!!

[Graham2]

My experience is with V8s, but you should be able to follow a similar procedure with yours. Look for two pipes going through the bulkhead from the water pump,  it varies from engine to engine, but you should be able to find them. Undo the jubilee clips, and pull off the rubber pipes from the metal ones. You'll probably get a dribble of rusty water out of one, and [!Expletive Deleted!] all out the other one. Connect a hose to the one that had very little coming out of it, and blast all the gunge out with the hose. Swap from one to the other a few times until the water runs clear. Put one pipe back on, and put the hose on the other pipe until no more will enter, this fills the heater matrix back up again. Connect the other pipe and start her up. You'll be amazed at how quickly it heats up, and how hot your interior becomes. You're doing it just in time for winter. Good luck. Check your antifreeze mixture too.

[Range Rover Blues]

Well I know from experience that John's heater did throw out some heat when the engine was running hot.

I've had a plsy with Julie's TDi and I find as soon as the engine has little work to do the heater (300 series) takes all the heat out of the engine.

John, when the heater is lukewarm, where is the temp guage, does it dip at all?