I have a strange problem with my heater. The car is a 2006 X-Type with the 2.0 Diesel motor. The problem: when I drive the car, the heater only blows cold air. after I drive for about 10 to 15 minutes, I must stop, wait a few minutes and restart the engine. Then the heater works normally, until I park the car for a few hours. If I drive off after 2 or 3 hours, everything is fine. but if I wait - lets say - overnight, the same problem starts again. Now, the car always took very long to start heating, usually ca. 15 minutes or 5 miles driving. It bothered me very little since I hardly ever drove the car in winter. But things have changed and I need the car sometimes when it is cold outside. I have replaced the thermostat, checked the coolant level, even disconnected the radiator fans. Nothing makes the problem go away! What am I missing? I would appreciate any help greatly, thanks in advance!

this is the patient
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It looks as if the thermostat no longer works. The temperature display should no longer show the usual value, i.e. the middle position. Location Austria, district of Melk?

 

Hi Jo! Yes, that was also my first thought. Unfortunately, the replacement of the thermostat brought no change. If anything, it got worst ! About my location: yes you're right, it is the District of Melk in Austria! This is my birthplace but I lived in the US for nearly 30 years. Van Haag sounds rather German or Dutch. Are you in Europe?

 

My best guess would be a clogged heater core, sometimes you can do a reverse flush to clear it.
Hope this helps-Andrew

 

Well, that would be a possibility, but it would not explain why the heater works normal after a shutdown and restart of the engine. Or am I missing something? I noticed another phenomena today: when I leave the heater switched to "windshield defrost", it works without the shutdown/restart. At least, that what happened yesterday morning. This car has a live of its own it seems, but there got to be a way to fix this annoying problem. The Jag dealer would probably replace countless parts for countless Euros, with or without results. This is not in the budget! I got to find and fix this on my own......

 

Forgot to mention: it works only if the "Defrost" is still on from the day before, simply switching it on after startup is not helping either.