Hoping someone can help here: I have a 2007 GMC Sierra with the 5.3L AFMS motor and it has a little over 80k on it. In the last 15k miles or so, Ive noticed that after about 1500 miles after an oil change (mobil 1 - 5k intervals) I'm getting a low oil indicator on the diagnostic system - sure enough, a quart low or about 20% of the capacity. It also will happen right after heavy towing or higher RPM distance driving. I have no leaks evident on the block and no blue smoke... showing a heavy burn. I do get a whif of burnt oil sometimes after I shut it off and walk around the front of the vehicle. The oil level is topped off after the changes and I'm not sure where it's going. I was thinking maybe the AFMS running on only 4 cyl may cause it to bleed into non-firing cylinders and evaporate, but that sounds real wierd too.Any one have a similar issue and/or is there a GM notice out for this condition? Starts/runs great with no loss of power - does have that damn slight knock sometimes when idling after start that they're famous for.
Thanks a bunch!
JJ
