I picked up an '07 4Runner with 163K miles, 4.0L V6 as a project...chronic P0016 variable valve timing error, bank A. Pulled the passenger side valve cover to verify timing and found a minor sludge-fest as shown in the pics below. Maintenance records are very sparse on CarFax and Toyota, the original owner said he had a local shop do the oil changes at 5K mile intervals, unknown oil brand. The P0016 code is gone after removing and cleaning the intake cam (sludge accumulation in the VVT oil passages) and replacing the big VVT actuator on the front of the intake cam. I'm running Rotella T6 0W-40 and a Toyota filter. Will be back under the valve cover soon to replace the [censored] aftermarket #2 timing chain tensioner, the nylon pad is being touched by the #1 chain at idle causing a clicking sound.
Sludge pics below, feedback is appreciated:
Sludge pics below, feedback is appreciated: