How does engine replacement affect car's value?

Yes. Collector thing. I owned a “1990” Mazda RX-7 GTUs. Mazda did not produce a 1990 GTUs. They were considered rare at about 400 examples. They were actually left over 1989s sold and registered as 1990s. Mazda did this with other years and models. Mine was produced in July 1989. I consider paperwork automobile “rarities” total BS. It was sold and registered in January 1990. The 1989 Mazda RX-7 GTUs had some factory goodies. Turbo brakes, Turbo transmission, Limited slip differential, and manual window cranks which saved maybe a couple pounds. I advertised my deteriorating car for $1,000 and sold it for $900.

Thank you everyone for these insights. The car has 88,000 miles on it and Ford Escapes have been subject to recall in the past for this exact problem, even my mechanic agreed a recall on my particular VIN is likely. But the points some people made about the overall age of the car is a good one.