Porsche Repair: porsche 924, porsche 924s, serpentine belts

Question
how ya doin dave
i emailed you some time ago about my 87 porsche 924s.  i ended up changing the battery and it started right up with no problem.  however there is a loud clanking sound coming from the engine, i am not sure if it is a belt or maybe even a cylinder piston.  i gave the car some gass and the noise just speeds up and slows down with the gas petal. when i shut the car off it smelt like something was burning in the engine, i know that the oil is low and probly needs to be changed so that might have bin the smell but i am still confused about the noise.  i havent tried to drive it at all,  i worry that the noise coming from the engine might become more severe if i actually put it in gear.  
thanks for responding to my last inquiry and i hope that you may be able to help me with this one.  

happy  

Answer
Happy,

I'm glad you parked the car.  

The first place to look is the condition of the "timing belts."  There are two: the camshaft belt and the balance shafts belt.  They are both rubberized belts looking like the ribbed serpentine belts seen turning the alternators and power steering on a lot of new cars.  Problem is, the belts are buried inside the engine where you can't easily check them and where oil, grease and grime attack them.  If you do not have proof these belts were replaced in the last 20,000 miles...or if they were replaced but not re-tightened after 2500 miles, we should expect the worst and hope for the best.  These belts can easily break at 25,000 miles and when they do they take your expensive engine parts down with them. UGH!

I have much more info on the subject, but first, what do you know about the history on your belts?

Dave