Try using a mechanic stethoscope to probe the timing chain cover for noise. It might help to remove the belt to eliminate some noise. The timing chain tensioner or guides might be a possibility. I would try pin pointing the noise first. If you don't have a stethoscope, a long screw driver may work instead.
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82 F150 LWB 306 cid
83 F150 306 cid
00 Taurus 3.0 OHV
82 Chevy p/u 305 cid
02 C1500 HD 6.0L (Sucks gas)
08 Corrolla S 30-35 mpg  | 
