Toyota Repair: 87 Toyota Cressida oil burning problem, toyota cressida, bore scope

Question
Hi Ted.

I have a 1987 Cressida (5MGE engine). It smokes (blue) when it gets hot, in traffic jam or at idle mostly. Never at start up though. I am wondering if it is the rings that are bad or the valve stems or something else I don't know. If it is stem valve, is it something I can replace myself with the help of a repair manual? How do I know which is the problem? Does a bore scope help if I can rent one to look into the cylinder through spark plug hole? I have an estimate for a used engine as well, do you think replacing the whole engine is better than repairing the one on the car. I appreciate your help.

I have seen many other Cressidas with the smoke problem, is this a common problem in this line of Cressida (85-88)? If yes, do you know the cause?

Many thanks,

Amir

Answer
My best advice is that it is probably better to replace the engine, it sounds like a piston ring problem, valve stem seals normally only cause smoke on startup, I would not waste any money on renting a bore scope since the problem is obvious already, this engine sounds like it is just worn out and repairing it will cost more than just replacing it.