Was throwing this code (p 0335). Replaced harmonic balancer. Ran fine for a couple hundred miles. Today, ran fine then got louder and higher pitched engine sound. Showing 2 codes:




P 0236
P 0335
1998 chevy one ton 6.5 L turbo. 165K miles
Any help greatly appreciated.

 

P0236 is a turbo boost problem. Check your main vacuum line leading from the vacuum pump to the bank of solenoids on the driver's side. Check all those vacuum hoses/plastic elbows/t-connectors in the bank for signs of a vacuum leak.

Don't know anything about P0335 yet, sorry.