Toyota Repair: New Solara; general maintenance, belts, interference engines, diagnostic fee


Question
Hi there. I Just bought a 99 Solara SLE V6 with 71k on it. I've never owned a Toyota before (this is only my second car, not real familiar with maintenance besides changing the oil every 3k).

I was wondering what I should have checked or replaced on the car at this mileage, and if there is anything I can do to get more power/smoothness out of it for a few hundred bucks (filters, spark plugs, new intake, etc).

The only problems it has that I've noticed are a  slight oil dampness under the oil pan, and a quiet slapping noise when idleing; I mention the noise because none of our other Toyota's have that noise - maybe serpentine or timing belt going out - don't know if they were replaced or not by the last owner, but the V6 Camry's are non-interference engines anyway, right? I'll have the mechanic look at it this week if need be (but it's a $60 diagnostic fee...).

Thanks so much for all your time! -Matt G.

Answer
These are the items that should have been replaced at 60,000 miles:
The spark plugs
The air filter
The timing belt(this could be causing the noise)
The coolant
The engine oil and filter
The transmission fluid
Have the mechanic look at it and let me know what recommendations are made.