One other thing that is clicking is the fuel injectors.
Since these and the valvetrain are all so close together, I don't know one from the other as far as the sound.
The BEST source for advice would be from a qualified mechanic.......hearing it in person.
Many shops offer a "vehicle check out" for folks thinking of buying a used vehicle.
Well worth the small price.
These are very nice vehicles, and reliable.
I would check to see if they have oil change records, going an extended oil change interval is not advised.
5-8K miles between oil change would be the maximum I would go (8K if synthetic).
I do 5K oil change with synthetic, but I am one who likes to be really up on that sort of thing.
Maintenance recommended, at 90K the timing belt is due, if not already done, I would have it done due to the vehicle age.
It is NOT an easy DIY job.
Good idea to have the coolant replaced at that time as well, using TOYOTA RED (not pink) coolant.
These may already have been done, but if not, it is not a reason to not buy this vehicle, just routine maintenance that you should have done.
Some folks have the water pump replaced at this time as well, because all the labor of a timing belt job has to be done to get to the water pump.
Water pumps are much more reliable on vehicles today as compared to 20 years ago, so that would be your (or your mechanic's ) call.
It ran me about $500 for the timing belt and water pump job at a Toyota Dealership.
I would also REPLACE the PCV valve with a TOYOTA one (not expensive).
The PCV valve is mounted into the rear valve cover.....kind of on the passenger side.
On this motor, keeping a good PCV valve is CRITICAL in preventing "gelling" of the oil.
NOTE, that crusty looking stuff on the baffel that you see when you remove the oil fill cap and look down into the motor is NOT sludge.
That is a coating that was put on brand new at the factory (I think for sound deadning).
