Originally Posted by Pickler
when engine is under heavy load at low rpms (1000-3000) it makes a funny rumbling sort of noise. this is made worst if the AC is on or the outside temprature is hot. i use scangauge 2 to monitor engine load mpg etc and i noticed this noise comes up when engine load hits 99% (max load). this doesnt happen under full throttle. anyone experienced this with the 2.5L?
log knock correction or total timing angle or whatever you can monitor as far as ignition timing. It may be knock since knock is more likely to occur when intake air temps are higher and when load is higher (I.e. when the a/c is on)