2002 Acura RSX Rod Knock

Engine Mechanical problem
2002 Acura RSX Front Wheel Drive Manual 58150 miles

I am not sure of the engine size - but I went to get my Acura 2002 RSX - Type S appraised, and the appraiser said it had a rod knock when he was driving it around - I did not believe him, but now I have taken it to a mechanic who feels that this is what it is too - without doing to sophisicated of testing, and that due to the complication of getting to the rod in this type of car, it would be best to just put in a replacement engine - otherwise it could cost thousands of dollars to take a part of the engine, or worse, get a brand new one - this is not covered by insurance, any way, that these mechanics could be wrong or that a rod knock goes away in time - of note, the A/C was not working at the time and the car last year was hit by a deer (would that have had an affect on the car causing a rod knock)