has had a moderately loud tick for about 6 months. Tick frequency increases as the engine RPM increases. A back yard mechanic and a dealer have both said that the tick is not comming from the valves. The dealer said that they would have to take the engine apart to discover where the tick is coming from, which given the price of the diagnostic test, may not be worth it, given the age of the car (2001 Toyota Highlander, 207,000 miles). Last night, the check engine light came on as well as the VSC light. O'Reilly auto put their little computer on the car and said it was the knock sensor that may be bad. How should I proceed?
JA: Does the light stay on, or does it blink?
Customer: The light stays on.
JA: Are you hoping to fix this yourself? What have you tried so far?
Customer: I tried disconnecting the battery to reset the computer, but the light has come back on. I am not sure it is the knock sensor. Could the knock sensor be causing the engine tick? How should I proceed?
JA: Anything else you think the mechanic should know?
Customer: Yes. An engine oil analysis done two weeks ago read this:
All wear levels appear within acceptable limits for first sample. Silicon level (dirt/sealant material) satisfactory. Water content acceptable. Viscosity within specified operating range.