Summiz

Hey all,
My 03, 71K miles, has developed a "chug" from the engine. Oil pressure, idle, and power all read/feel perfect, fuel economy is on par, so I dont suspect misfire. It only happens under load, sounds like a freight train. Just fyi put in 6.5 Qs of Fresh 5w30 mobile one. The balancer had gotten to the point where tensioners are humming, but I don't know any correlation. Any clues out there?

C5 Diag

How about pulling codes first through the DIC if you can...this may put you into the right “diagnostic funnel” as a they say...this “chugging” can be the result of numerous items !!...you can disconnect the MAF sensor and see if it still chugs...can be dirty air filter, fuel filter, fuel pump, O2 sensor issues...without a scan tool and some diagnostic equipment you’ll just be guessing at this point !!

BigGun

You don't need tools to pull codes using the dic. That might at least give you a start.

Summiz

will do, thanks for the info.

Pounder

dirty MAF can cause similar issues !!!

Leftlane_1

My first thought would be MAF also. I remember one time i forgot to plug the maf sensor back together and the vehicle would hardly move unless I floored the throttle.