HELLO, Need help finding out about an engine replacement in my wives car back in 1996. It is a 1990 Corolla that had a Japanese motor installed with 40,000 miles on it. There is a 5A and numbers stamped on the case which means it is a 1.5L not a 1.6 that was original. I'm trying to figure out what year it was made to get replacement parts. It is over heating and I went to replace the thermostat and there wasnt one installed.The parts guy says they dont have a thermostat but that doesnt make sense to me. Anybody have any ideas? Thanks.