We have been having an issue with high charge air temp at the engine inlet. In the past several months, the temp has been slowly increasing, and putting us into a derate. The CA pressure at the engine inlet, and CAC Pinch, have both been increasing as the temp has been increasing. Both HT and LT water systems appear to be functioning properly, with no issues. New air filters, no restriction across the charge air coolers. Ambient temp does not seem to affect it- we have gone from -30C to +15C, and still have the same issue. Has anyone run into this before, or have any ideas?