I've been having problems with my heat this winter. It will blow out luke warm air. I checked the coolant level, and made sure there was no air in the system. Everything was ok. So tonight I removed all the panels to get to the heater core and did a little test. Here was the procedure:

-Warmed car to temperature
-Turned on cooling fans on high to maintain a constant coolant temperature
-Turned heater on high, left on for 15 minutes to achieve steady state
-Outside temp = 54°
-Coolant temp = 190°

Here is a temperature map of the heater core

Driver 81 118 143 Passenger

So my question would be, is it clogged up and therefore need to be flushed/replaced

 

I'm having a similar issue. I'm interested to see what people have to say.

 

I'm also having the same issue. Changed the heater core and the thermostat, flushed system. No difference. Checked heater flaps under the dash, all working properly. No air pockets either.

I looked for the heater core valve some say they have but I don't have one. I do however have a T intersection some have told me is a clogging problem so I will check that out. The inlet hose seems warm but not hot so I'm guessing there's a flow problem somewhere.

 

There is/was a flow restrictor in the inlet hose near the firewall.
It may be the problem. I think it just pushes in the hose but good luck getting it out.

 

You did an awful lot of work. I would have just flushed the heater core and observed what the heat was now like. Flushing solves 90% (or higher) of no heat complaints.

 

Flushing didn't work. Problem has to be inside the hoses. None of the traditional solutions work on this car. The cooling system is unique, and the hose system/regualtor is likely the culprit as witnessed by others.

 

shoebox did you mean flushing the heater core individually or for him to flush the entire cooling system?

 

I'm sure he meant the usual way of flushing just the core with hose. Best way is to flush it one direction then the other and repeat a few times until it flows nicely again.

 

I flush the heater hoses when I flush the core. IMO, it is the only logical way to do it.