I've developed what sounds to be spark knock but yet I'm not sure that's what it is (sounds like it though). Seems to happen around 2,000-2,500 rpm during normal acceleration, and usually only when the engine is colder and colder outside... about the first 10-15 minutes of driving. My question is this... doesn't normal spark knock/ping happen when the engine is hot, just the opposite? And yes, I always use 93 octane. About 56k miles on her now. Any suggestions on what to look at would be appreciated. Dealer checked and found nothing, claimed it was a shield, but adjustment did not help at all.

 

With a computer controller car like the TL, the engine can very much still ping even with freezing temps outside. The car's computer will just increase the ignition timing even more when the outside temps are low to keep the engine efficient. So no matter what the outside temp is, the computer will keep the ignition timing at the threshold of knock if the Intake Air Temp (IAT) sensor and the Knock Sensor readings allow it.

And, the computer is probably allowing the slight knock that you hear because the computer and Knock Sensor are tuned to pull back timing on major knocking, not the mild knocking that you hear.

Valve Chatter/Pinging/Knocking in 2007 TypeS (click here)

 

Thanks. I read a good bit of that thread yesterday and drew no conclusions from it. Sounds like this is just something I should not worry about then? It isn't terribly loud, just takes away from the smoothness of a clean engine rev at times. I was more concerned about long-term implications on engine life. Love the car otherwise and would like to get 200k out of it if I can.

 

In stock form, I could easily make my TL ping by loading it up at low RPM. I also run only 93 octane.

Isn't it crazy what a dealer will tell people just to make them go away.