I have 2006 TrailBlazer nice vehicle. At 135000 noticed a ticking sound coming from the front of engine. Had an overall check. There was no ticking at the time, only does it when engine is cold or hot. Tried a thicker oil, still the same problem. Sounds like a bad lifter. It goes tick tick tick and stops. Overall no other problems. I always change oil every 30.0000 miles. I read the reviews that other people are having the same ticking problem. Help.