I just bought a 1988 supra turbo for 900 bucks knowing it had an engine problem. It was leaking oil and had a small knock but otherwise it sounded good. The engine was apparantly rebuilt some time ago, but when I did some inspections, I found the retainer ring for the oil pump driveshaft was broken. Of course that is where the oil leak was. From what I've read so far, this doesn't seem to be a common problem. The shaft goes in and out of the engine about 3/4 inch although it didn't go in that much when the pulley was on it. The rear timing belt housing has damage where the pulley was rubbing but the housing is still ok to re use. I read from a search that if the shaft goes inside the engine it can contact one of the rods. Should I completely tear this engine down or just fix the shaft and hope for the best. I am new to MKIII's and would appreciate some opinions.