Automotive Air Conditioning Information Forum

Excellent history report and references to comp and txv designs. Your BIG ears cause concerns that most people never consider. Hard to hit the nail on the head by remote analysis w/o pressures.
1) 2000 Tracker had a small Denso evap matched to a sanden SDB very small 87 cc fixed displacement comp, therefore 125 cc at full displacement would be unbalanced.
2) During low charge operation more oil remains in the evaporator and comp lub suffers but the front comp housing did not overheat which would have degraded the shaft seal. 3 low charge exposures could cause increased piston radial clearance and abnormal blow by into crankcase of oil and gas thereby keeping the swash plate angle more than the factory design.5) VDC are noisy at abnormally low suction pressure or low oil return.
You may install service gauges and tape to the windshield while driving and recording pressures. I always disable the wipers.
3) proper oil quantity is dubious.
4) Correct cross charge for super heat management is important for several reasons you noted + stable swash plate angle/displacement to avoid hunting/temp swings. Orifice tube expansion device prevents hunting because the comp control valve is (basically) the only/single flow control device.
6) Excessive OCR (causes gurgling downstream of TXV and may delay comp control valve response to pressure change.Hot comp housing start up should njust be barely noticeable at start up,
hotrodac

BIG ears,
Some cars have a heat shield between the back of the comp and the exhaust (Civic). You could try that.
Liquid refrigerant condenses in the coldest place in a static system. In your conditions that is the evaporator where lube also collects. The liquid storage receiver is probably in the hot engine compartment instead of where it belongs forward of the radiator so that all it's liquid refrigerant does not migrate into the evap during short parking times.
You may have excessive lube.
To avoid retained standing water in the evaporator (and mold smell) overnight, I turn off the comp and run the blower before reaching my destination. You might try this on short trips so that the evap is not so cold while you hike, etc. his might reduce liquid slugging that could hinder the comp control valve operation. Some control valve designs have a bypass passage to allow flow of liquid refrigerant or lube. Y
hotrodac

Compressor built in mini oil separator can be rendered ineffective by wear particles plugging the oil return hole which would increase oil circulation throughout the system but only very minor effect on cooling. An indicator of compressor wear is a dark grey lube color caused by aluminum fines.
hotrodac