I just did some maintenance on my Acura tl I just got (2005 Acura tl base) and am now experiencing this knocking noise. It comes on about 30 seconds after cold start then fades away as the engine warms but never disappears completely. I did the tbelt, tensioner, water pump, thermostat, spark plugs and valve adjustment. I currently have no CEL and the car runs great other than the annoying noise it makes now. I changed tensioner twice and valve adjustment twice so I know it can’t be those. I’m leaning towards piston slap but let me know what you guys think I would really appreciate it, thanks!

 

Here is a link to the noise:

 

Mine is making the exact same sound and I purchased it 2 days ago. I was going to do the valve adjustment but I doubt it'll fix the issue. I'm 99% sure we have piston slap, although mine is still pretty audible even after the car warms up. I don't hear anything for the first 5 seconds of a cold start.

 

Yup, same exact thing here. No noise for first 30 seconds-ish on cold start then it comes on. Valve adjustment will not do anything unfortuantely. Neither does the tensioner. People say the J35 engines can still go a long ways with this "piston slap" noise, however im taking it in to a professional to get a second opinion tomorrow and I will let you know how it goes.

 

Please do! I've been reading the same thing about engines still lasting with piston slap. The only thing is that we may need to keep track of oil levels.

 

Question.. how did your “piston slap” evolve anyways? Did you do any service that caused your noise to begin or did it just start happening over time?