I have a 2001 Blazer 4.3L with 100,000 miles on it. The engine runs well and burns no oil in between religious 3k mile oil changes. Oil press is normal and has no signs of problems. I took my blazer from Illinois to Texas and back which is around a 2300 mile round trip. Once back in Illinois I noticed a ticking/clicking noise coming from under the left back side of the engine. It's not very distinct from under the hood but can be heard when standing by the driver's side door. The noise is about impossible to hear from inside the cab though. This ticking varies directly with engine RPM and stays about the same noise level throughout. The noise becomes more prominent when the engine gets up to temp also. I have not gotten the chance to get under the engine to check it out further but figured maybe I would find someone on here that could enlighten me. I greatly appreciate any ideas! Thanks!

- Mike

 

Sounds like you may be experiencing a collapsed lifter. How is your oil pressure?

 

Thanks for the reply. Well, I've been down the collapsed lifter road before and this isn't quite the same. About a year and half ago I did replace all the lifters. When I had that problem, it was a more of a louder metallic ticking sound coming from the valve cover area. Oil pressure is good and sticks around 40 PSI when cruising down the road which has been standard for my blazer. Although I love my Blazer, after the work I've been putting into it lately, I'm starting to think it's time to get something newer. Hopefully this one doesn't make too big of a dent in my pocket!

 

If it does not sound like it is coming from the valve cover area, but more towards the back of the engine, it is possible that it could be the beginning of a broken flex plate. Before the flex plate broke completely on my old 85 S10, it ticked a bit. I thought it might have been an exhaust leak from the initial noise, but there were no leaks.