I am going to buy a 99 Toyota Camry. I found the engine is not clean. I want to know how I can tell the engine is not rebuilt or repaired.

 

I would have whoever your buying the car from clean the engine compartment. Then you might be able to examine the engine for evidence of repair work. Like bolt heads that have been excessively wrenched. Silicone at gasket seals. I don't know...just some ideas.