The variable valve timing camshaft actuators may stick due to dirty engine oil or a faulty control solenoid. A sticking actuator may cause a rough idle and the Check Engine Light to illuminate. Our technicians tell us the engine oil should be checked to make sure it is clean and at the proper level before replacing any parts to correct this concern.Google+
Car Problem Reports
Chevrolet Trailblazer Sticking Camshaft Actuators Due to Dirty Oil or Faulty Control Solenoid
Chevrolet Trailblazer Problem
Engine Affected: 4.2L 6 Cylinder
Average Mileage: 126,875 mi (42,000 mi - 200,000 mi)
Visitor, 2002 Chevrolet Trailblazer, 157,000 mi
rough idle, horrible gas mileage (8 mpg on a good day), hard start, hesitation at take off, dies when you come to a complete stop and after numerous cranks engine starts again....
Visitor, 2002 Chevrolet Trailblazer, 200,000 mi
Check Engine light stayed on. AutoZone checked the code and it was "oil viscosity, Cam Actuator". No real indication of a performance issue.
Went through several oil changes at my usual shop, all with Valvoline High Mileage (extra cost). No change. Read several posts about pulling and cleaning the actuator screens. Before I had a chance to pull the actuator, I won a silent auction for an oil change at the local Firestone shop. Kendall GT-1 Synthetic Blend. Two days later the check engine light went off and hasn't come back on since.
Not making a product endorsement here..just reporting the facts, and suggesting that maybe you r first step should be to switch oils/types and see if that helps.
Visitor, 2006 Chevrolet Trailblazer, 4.2L 6 Cylinder, 42,000 mi
open issue... Going to try an oil change... Cross Fingers!
Service Engine light comes on intermittently. Still an open issue. Plan to pull actuator and clean it.
rough idle, sounds like a 18 wheeler, took it to chevy dealer, and was advised that camshaft actuators does not work long and the dealer stated I need a new motor.