My 96 Z28 has 114,000 miles on it now. I recently installed a 160 stat in place of the stock 180, along with lowering the fan temps with a HPP+. I now have a ticking that I didn't have before. It didn't happen instantly, but probably 300 miles or so of driving. It is either a valve or lifter, not sure which. I'm thinking a valve. I am thinking the 160 stat may not be letting the oil heat up enough, and that's why I'm getting this tick. I am using Castrol GTX 10w40.

Around the same time I installed the stat, I put a 20 oz. bottle of Chevron (The truck and SUV bottle. Car bottle is 12 oz.) fuel system cleaner in with a full tank of fuel. Could this have caused some grit to break loose from one of the valvles or lifters? I don't know whether that is the reason for the ticking, or the cooler engine temp. Any opinions would be great!

 

Anyone???

 

I really believe the ticking with these cars is the injectors. My car is a 97 with 61,000 miles on it and I got it around 53,000. One day I noticed the noise but am not sure it was always there. Anyway, it could have started when I began using STP fuel booster. Well I really believe it is a harmless noise. The ticking is just to high pitched and light sounding to be a valve noise. However, that is just my .02 cents

 

Ya gotta find it before you fix it. Get a cheapie stethoscope from Auto Zone or somewhere and listen to each valve cover to determine which bank needs a look see. Pull the cover and check each valve, rocker, etc. to isolate.

If ticking is not in valve cover, it may be a plug, gasket leak, etc.
Trick is to eliminate the sources starting with the easiest to check and go from there.

I doubt that your oil is the problem, but if you have a bad lifter, you'd still think that after a short time after start that the lifter would pump up and the noise would go away.

Isolate, isolate, isolate. JMHO

 

Yea the injectors always scare me at first until I realize that its them and not something else.

 

Bad lifter is usually a 'clacking noise' . Not a bad idea to get a stethoscope but don't get to excited b/c there is a distinct difference between an injector 'tick' and a lose rocker or collapsing lifter noise. You can also just get a long screw driver and put the tip where u think the noise is and put your ear on the end of the handle........and use this as a stethoscope.

 

Thanks guys! It does seem kinda weird that I didn't have the problem until a strong dose of Chevron Fuel System Cleaner.