01 LW300 heater

Now that the weather has turned warm, I am noticing that even with the
heater control full counterclockwise, the air temperature from the duct is
still hotter than the outside air.

Any ideas on why this is? Not sure if it is in the internals or just air
heated by going over the hot hood and into the intake. I'm pretty sure that
the gasket between the firewall and hood is tight so no hot engine
compartment air is getting sucked into the duct.

Oppie

 

My 97SL2 breathes warm air into the cabin also with the temp control in the
cool position. Maybe a HVAC guy can comment (I'm curious too)...

 

The external options are that;
1) Either warm air from the engine compartment or air heated by passing over
the hood gets to the ventilation intakes

2) The firewall is heated by the engine compartment and passes this heat
through to the ventilation system.

Internal options are:
1) heater mix door control incomplete closure. Not sure yet on my L300 if
the mix door is controlled by cable or electronic.

2) Many cars have a heater water shutoff/bypass that turns off the flow of
engine coolant to the heater core. Again, not sure yet how the L300 does
this.

I keep planning to get the service manuals and a subscription to Alldata.
Finances have been a bit stained lately and had to put off non-essential
purchases.

Made several trips lately NYC to Boston and the LW300 has been averaging
about 26mpg on the highway at an average speed of 70. (we have hills here,
this isn't the midwest)
I miss the old minivan that had no center console and I could stretch out
more. All in all though, the LW300 was very comfortable for the 3 1/2 hour
drive each way.

Change oil soon light just came on for the first time since I bought the car
in January. 5K miles since then and added one quart of oil last month. Will
change the oil this weekend.

Regards to all
Oppie