What is this ticking/tapping noise?
 

Seems to be more pronounced after I recently used Mopar Combustion Chamber Cleaner. Clearly audible in the cabin with the windows up, and seems most prominent from the passenger valve cover.

video

Thanks!

My 02 ss has it I have been told it is piston slap but Im not sure myself. mine is louder when the car is cold, then fades as it warms

I've had this problem since Oct 2000 on a 2001 Z28. Same noise, same location. It developed 2 months after delivery, at about 2000 miles. Under warranty, GM replaced the A/C compressor and all of the plugs, as well as the headers. Nothing worked. They finally had their GM factory rep authorize pulling the pistons, finding no.2 was out of spec, and replacing it. Didn't fix the problem. They swore it wasn't a lifter, having checked and re-checked twice. I finally gave up.

The ticking quiets down as the engine heats up, and is only noticeable at idle. On very hot days, when the engine runs at the top of the normal temp range, the tapping disappears sometimes, making me suspect it really is a lifter problem. I blocked the radiator one time to run the temp up and check it out and it seemed to work. However, she runs great so I just let it tick its little heart out.

Had a similar experience with an 83 Buick, the first, last and only 6 cylinder I ever owned (or will own). The engine used lots of oil from day one. I suspected the engine was running too hot, vaporizing the oil. GM tested and retested, claiming it ran in the normal temp range. Under warranty, they replaced valve guides and several other components, with no improvement. I persisted, and the GM factory rep authorized a short block. After this didn't help, I gave up at 20,000 miles and just bought lots of oil. At 45K miles it began to overheat on hot days. At 80K miles I had to replace the radiator. The problem disappeared. So much for expert GM diagnoses.

Moral of the story. GM will spend thousands replacing parts if their tests say your problem isn't what you suspect it is, rather than taking a chance and spending a few hundred based on your experience with the car. Although I'm sure you have no warranty, don't let GM (or anyone else) convince you to try their cure(s). I think its either a lifter or the belt tensioner. The belt tensioner is cheaper.

I agree with iroczen. My car only seems to do it when the engine is cold and goes away after the car warms up. To me it sounds like its coming from underneath the car. To this day I still haven't been able to figure out what it is. :mad:

I have a similar tick w/ my '00 Z except that I can't hear it when it's cold, only when warmed up. I'm guessing lifter tick.

We thought that with my buddy's 00 Formula. He wanted different heads so we changed everything from the block up. Heads, lifters, pushrods, rockers all new or different and the warm occasional lifter type tick was still there. So he decided to let it go on until he put in a new low compression short block. When I tore the old motor down we found a chunk missing from a lobe on the cam. We missed it on the first round of mods because we didn't remove and inspect the cam and the damage to the lifter roller was so infintesimal that I missed it. I dug out that old/first set of lifters and used a magnifier and found some wear on so we know that the cam was the cause all along.

I haven't ever heard anyone mention cam problems associated with the infamous ticking problem before. Perhaps its a quality problem, which would explain why some never have the problem and others can never find it.

It developed 2 months after delivery, at about 2000

I had the same problem with my 2001 ss but at about 500 miles and the dealer was not able to correct it. Ticks when cold and goes away when warm. Car now has 14000 miles on it.

This is almost always piston slap and is not a problem at all. The piston shrinks when cold and taps back and forth in the cylinder until it warms up, which usually happens within seconds of startup.

Mine takes about 10 minutes to go away

Mine almost never goes away unless it is very hot. In fact, it seems more noticeable when it is warmed up, probably because idling speed drops. Above 900 rpm or so, its not very noticeable. At idle (550-600) its very noticeable.

My car sounds like it's doing 99.9% the same as your car is doing, except my ticking will go away completely once warm. About 10 min.

that is the definition of piston slap, nothing to worry about

op, have you checked for an exhaust leak around the header flange, maybe a loose or missing bolt

Read post #6. If you don't have an exhaust leak your discription sounds like cam lobe failure.

My 02 z has the same tick it develops cold and then fades,after many complaints and trips to the dealer i was told it was an inherent problem of the ls1 and they would monitor it.code for we dont know !!!
It doesnt seem to bother it so oh well