What was found
CLIMBING THRU 18,000' AND JUST TURNED ANTI-ICE OFF, WE HEARD A LOUD BANG FOLLOWED BY MULTIPLE BANGS, WITH VIBRATION AND A MOMENTARY SMELL OF SMOKE THRU THE ENVIROMENTAL SYS. LEFT ENG ITT WAS IN THE RED WITH NO OTHER ENG PARAMETERS NOTED TO BE IN THE RED. WE SHUTDOWN THE ENGINE, DECLARED AN EMERGENCY AND PROCEEDED WITH THE ENG SHUTDOWN CHECKLIST. R & R THE LT ENGINE AND OPS CHECKED IAW MM 71-00-02 AND 71-00-03. OPS AND LEAK CHECKS GOOD.