Regional Jet 900 (CRJ900)
Flight Crew Air Transport Pilot (ATP)
Aircraft Equipment Problem Less Severe; Inflight Event / Encounter Wake Vortex Encounter
General Declared Emergency
Aircraft; Environment - Non Weather Related
Descending into ZZZ; I was given a hold due to congestion at the airport. While entering the hold at 23;000 feet and 250 knots; we thought we hit somebody's wake. It was a quick chop then it happened two more times. The third time we noticed ITT left engine suddenly fluctuate; and we felt a chop in the aircraft. We put on continuous ignition thinking maybe a compressor stall. We tried to find a check list for it but there was none; so we went to compressor stall in the non-normal check list and there was nothing pertaining to our situation. We were 35 miles from ZZZ1; weather was 5 miles and haze; winds out of the SW. ZZZ was 50 miles; but we were pointed that way; so I decided to [advise ATC] and head for ZZZ. I also advised ATC to request Aircraft Rescue and Fire Fighting (ARFF). The engine parameters were never exceeded. The engine fan was LE 0.0; right engine 0.2. ITT was 656; LE 610; RE N1 was 73.9 both engines. Coming into ZZZ I moved the thrust levers to idle and up to 80% for normal arrival power settings; also the flight attendants reported loud bangs on the side of the aircraft. Inbound to ZZZ it did not do it again. The weather was clear and no icing. It seems when the ITT on the left engine went to 50 degrees more than the right engine; it would do it again. We were concerned it might shut down.
CRJ-900 Captain reported that after a wake vortex encounter in a holding pattern; the left engine ITT increased abnormally; perhaps due to a compressor stall.