nednj36

The infamous 1500 RPM driveline drone/hum/whistle might be due to gasoline & the engine management computer. The drone on my 2005 TL 5AT has gotten progressively worse in the last 5,000 miles (currently have 16K). I experimented today and filled up with Sunoco Ultra 94 and the drone is noticably reduced. Along with the drone, you can feel a slight miss with gearshift in "P" and slowly steadying the gas pedal to 1500 RPM. The idle gets bumpy and you hear what seems to be an exhaust or manifold leak. It could in fact be the cross pipe heat shields as alluded to in the tech bulletin.

pvansh

You mean you can hear the noise in Park holding the revs at 1500 rpms?

I've noticed that sometimes the drone is worse then others but I havent been able to pinpoint it to octane. I also have never used Sunoco Ultra94, maybe I'll give it a shot.

nednj36

You feel, not hear, a bumpy miss when holding the idle at 1500 RPM with gearshift in park position. There is also a strange ping at 1500 (car stopped & in "park" position) the ping almost sounds like the lifters or valve tappets are louder than other RPM's. It might also be that mid shaft heat shield they're talking about.