Move the temperature sensor.  Heat from the engine compartment comes through the cowl and all you have to do is feel the cowl after landing to get an idea how much heat is rejected through the side of the cowl.  This heat generally stays in the lower portion of the boundary layer following the general flow aft on the fuselage..
    You should move the probe somewhere that is not directly downwind of the cowl (few places on the fuselage work well, except for the rudder inlet of the IV).  I moved mine out on the wing a short way.  On my LIV I placed the probe on the front of the cowl with some foam insulation on the back of the probe to stop IR radiation from effecting the temp.. Works good lasts a long time.

Jack Webb

L 360, L IV
ATP, CFI Airplanes & Instruments, Multi, & Sea
Many Type Ratings
Experienced Experimental Test Pilot both multi and single engine
Former Chief Engineering Test Pilot for a Major Manufacturer
AeroSpace Engineer BSAE
Ohio