Theres a lot of ticking/clattering coming from the valvetrain. Is this normal?
For the Impala, it is normal. The increased noise is due to the metal valvecovers used instead of the thick plastic ones on the Corvette. The LT1 is bad in this respect. A TSB has been issued that covers some of these noises. Contact your dealer if you are concerned. The TSB follows: Chevrolet 67-61-14 Issued 04/18/96 Models: 1994-96 Buick Roadmaster 1994-96 Cadillac Fleetwood 1994-96 Chevrolet Caprice, Impala SS With 4.3Lm 5.7L V8 Engine (Vins w, p – RPOS L99, LT1) Subject: Engine Noise (Install Valve Stem Oil Seal) Condition: A rhythmic engine noise at idle. The noise, which occurs at half engine speed, has been described as a “whoop whoop” (similar to a helicopter idling), and engine rattle noise (not to be confused with pvc rattle), a lifter tick in the lower end, a balance shaft noise, or a rod knock. When using a stethoscope, the noise will sound as coming from deep within the engine. The noise may be heard in the passenger compartment and in s/t vehicles is audible at the cataly
