Hey guys

so I was stock for 50k miles. While stock every single cold start (engine coolant under 100) i would get a sorta loud taping sound. It was comming from the top of the motor but couldn't really find out where. GM "techs" said it was piston slap, but I told them it seemed a little loud. Once the coolant was at 100 the sound would quiet away within a minute or so.

So now I have GM stage 2 installed. NO tap sound on cold start, and the motor seems to run much much smoother. I dont know if thats result of the tune, or I had a faulty injector? Any idea here? Anyone had this problem before? My stock plugs visually look fine.

ok

 

not sure, but ive heard of many peoples cars quieting down once they are re-tuned

 

ya I was wondering if that had a lot to do with it. My exhaust actually quited down...I actually like it a lot more now lol but i'm thinking I shouldn't re-sell these injectors... dont want to sell a faulty one

 

I know when i had my balt there was a taping the tech said it was from this air sensor/filter i can think of the name of it, which was making a tapping sound. When it warmed up it stoped. Damn i cant think of what it is for the life of me.

 

i had the same tap at cold start. but its a 4 cyl... so i figured it would do that cause my other cars never done that and they were all v6's. but after i'm warmed up above 100 degrees she is perfect. i wouldnt worry about it. it went away so dont think about it lol

 

lol ^^ okey dokey stage 2 is the ****..

 

GM has had a problem with piston slap on alot of their vehicles, this is generally not a problem but one of the fixes was an update to the pcm that altered ignition timing events that made the noise almost dissappear. The LS1 engines were bad for this. Stage 2 has new timing maps that could indeed have made the piston slap less noticeable.

 

great info man! thank you. I was thinking the same it could be that also, but I didint really know about the whole piston slap deal until recently. Damn stock tune sucks huh