Interior coolant leak.

[Burning oil]

fyi you only get a reflective r value when there is an air space.

Yep,
In my attic I used radiant barrier foil. Stapled it to the rafters with a 4-5 inch air gap. Shinny side down (facing in) to help keep a dust layer from covering the shinny side and reducing its reflective quality.
Same principle would apply in a vehicle.

 

[Paveltolz]

Trying to keep the summer heat out. The truck stays plenty warm in the winter. I've fallen asleep (at rest stops) in sub zero weather with just a jacket over me and it wasn't until 4 hours later I woke up chilled...to the fricken bone, but I got good sleep.

Yeah, I got the air space reflective R value thing down pat. 18" of blown pink stuff in the attic and radiant barrier going in this year.
I got the dense/solid RAAMmat sealed to the metal floor pan, 1/8" thick EVA on top of that with the wires and cables between it and the RAAM. 1/4" reflective sided mat, OEM carpet with 1/2" new carpet padding and 1/2" fiberglass w/ reflectant (OEM) over the "hump" and under the passenger side to protect interior from Down Pipe heat.
Ride in this morning wasn't silent by any means but it was noticably quieter than before. I credit the RAAMmat as the drive in yesterday was about the same with just the matting as it was "Pre Spillage"

 

[nealpellecchia]

That is absolutely ridiculous.

yeah, listen it's a snap. take the screws out of the bottom part of the box. bend the plastic back to expose the core, take the screw out that holds the core in position. then pull out the core after disconnecting the lines from hoses in the engine compartment. hose clamps are b.... as is the holding back the plastic and removing the screw that holds the little bracket that holds the core in place. but no 6 hours more like 60 minutes with practice.