I went to town on the freeway, about80 miles round trip and 75 mph. I had a leak that appears to be coming from the lower rocker box gasket on the rear cylinder and hits the Heat shield On the head pipe. I wiped it down and had to go again, about 100miles round trip and 60mph-- got home, and no evidence of more leakage, it was dry. I bought the new gaskets but I'd like to verify before changing them out. Any ideas? Btw, no evidence at all that it is coming from the throttle body area-and blowing back- 03 egc. Strange

 

Sounds like standard issue blowby, I wouldn't go changing rocker box gaskets considering this.

 

I had the same problem, noticed it after riding about 4-500 miles over a couple of really hot days, including idling in rush hour traffic and EITMS kicking in.

I checked my oil level, it was not down to the add part but I added about 3/4 of a quart brought it back up to top mark on the dipstick for hot (usually I have it at the halfway point so I won't have blow by). I took it to the dealer they looked it over, no oil from the air cleaner, around the air cleaner but oil spots on the near the starter, and on the fins and on the heat shield. The folks at the dealership said the same thing you assessed. I made an appointment.

I wiped it down, cleaned up the oil, rode it again 400 miles, umm no more oil, rode again today in rush hour to work, hammered on it a few times, no more oil leak. Canceled my appointment. I wish all problems were solved like this.

I just hope it doesn't come back before Thanksgiving so I an finish up riding through summer and a bit into fall.

 

It seems, with mine, that speeds approaching the80's for about a half hour on hot days, it does it. Just running around town, it does not do it. And I went back and checked every inch of the a/c and associated throttle body, and everything, inside and out, is bone dry.