Ok, so now that I'm home I'm trying to diagnose my lack of cabin heat further.

I parked with the nose up on my driveway, it's pretty steep, I removed the cap and plugged my scan tool in. I let her run for about an hour that way with the HVAC system off. It took roughly 15-20 mins for her to get to 160f, in minus 14c outside temps.

That's where she's staying. She'll get up to 163, then comes back down to 160. The dash needle is smack dab in the middle. So I turned the HVAC on, HI HI and full fan speed. The air coming out is barely warmer than the ambient air.

I'm leaning towards a stuck T-stat as there were no air bubbles in the tank while she's been running with both the heat off and on.

Anyone have any better ideas?

 

radiator muff. It's made for temps like yours to help keep the warm in

 

If you're up to 160F, you should have cabin heat regardless of the T-stat. Have you verified that your heater core is not plugged?

Once you're up to temp, both heater lines running to the firewall should be warm. If one is warm and the other still cool, you found your problem.

 

For 100% heat make sure to turn on ECON (which turns off the A/C Compressor 100%). If you don't the system will still run the compressor to try and keep it from fogging up.

If you're running 160F in that cool of temps either block some of the radiator to help it warm up, or make sure you've got a 190F thermostat vs a 180F unit.

14C = 57F so a 180F thermostat should be producing some heat. Make sure ECON is on for 100% heat, and what does the heater do at highway speeds? If it's still barely nothing then yeah something sounds clogged.

 

Red5 is right on. X1
Should have heat if heater core not clogged or almost clogged, check heater hoses while runnng it on full hot, if one hose is way cooler then disconnect both hoses & flush the heater core backwards with garden hose, (backwards means force water in from colder heater hose) to get stuck gunk out, & before flushing put some "radiator flush" into heater only & wait 20min & then flush,,
If you can't do yourself most shops can do it for you,

 

MINUS 14C = 6.8 F degrees...

 

I wouldn't go with a clogged heater core...airbound maybe...


Maybe the heat **** isn't opening the valve...


Bad fan clutch stuck on...the fans running constantly, stuck open thermostat...


The 160...that's a good one.


The truck is sitting while running correct?

 

My heater core was plugged.. Would not put out any heat... period. I flushed back and forth with a garden hose through the hoses going to the heater core.
Found out it was plugged and it finally blew through. Now I have plenty of heat.


I have only tested to around 20 degree F., but found the Disco to have the fastest warming heater out of all my cars.

 

I didn't see the minus my bad. In that case there IS NO WAY you're going to just have instant heat at idle.

With a 180/190F thermostat, you'll have to either block the radiator off some or at least have the engine under load. Heck with a 180F thermostat here in SETX with lows barely below 35F it took me until I hit the interstate and 70MPH to get what I'd call decent heat output. I can only imagine 6F.

 

Luckily the one thing we are blessed with in our discos... Quick heat.

My Duramax Chevy truck heat finally gets warm after my wife gets to work!!! Joking, but seriously that truck takes forever to get heat.