C-15 Power & fuel issue

C-15 Power & fuel issue
Posted: Mon Dec 24, 2007 10:58:00 AM

I just purchased a kenworth w900. It has a c-15 500 hp. I get super milage bobtailing. When i hook on and put a load in the box

i get about 3.5 to 4 mpg. I don't push it hard but it seems to miss or a flutter and sometimes it doesn't seem like the turbos spool up correct. I did the fuel filter stuff with cat filters and all and i actually got best performance out of donaldson filters. I run east to west coast and back. This truck has bankrupt me big time. Can someone please help me figure out what is wrong with this engine. It has low power a miss or flutter and vibrates bad at idle. Ive also noticed that the jake brakes only work with this truck when you push on the brake pedal. I live in NJ. Ive been screwed so many times i have no faith in any shop.All they want is money and come up with no answers.

RE:C-15 Power & fuel issue
Posted: Thu Jan 6, 2011 1:33:14 PM

i have a 2001 freight-liner with 144k on it with a c-15 it was running rough maybe only 2.5 mpg i replaced the muffler which has the cat in it and power and mpg are very good  now are 5-6 mpg the muffler is very expansive over 1200 dollars also my rig is a car hauler