[rhumfeld]

Hi, i am looking for help on my 2003 Silverado 2500 HD. It has the 6.0L with 115,000 miles on it. I noticed a while ago, (2 months), that the truck was idling kinda rough. It got worse after a while and the engine light now comes on at an idle or when coasting or city driving. It also chuggs on starts from stop lights/stop signs. When sitting at the stoplight, the whole truck will shake and idle rough. It has not very much power on lower RPM (less power than I believe it should have. I can't spin the tires if i tried). Once the truck revs up it seems to be better. I have had a few different mechanics look at it. There are many, many miss-fires on cylinders 4 and 5 it is constantly racking them up when the scanner is connected. We have tried new plugs and that does nothing. We swapped injectors on 3 and 5 (one a good firing cylinder and a not good one), and it does nothing, swapped the coil packs on 3 and 5, does nothing. We finally decided to try a compression check and on cylinder 5 at idle it read 45 pounds. When i rev it up some, it reads 65-70. On the good cylinder (3) it reads 80 (i think) at idle, and 125 or so when it is revved up (2500 RPM.)

Basically i am just wondering if there is anything i can do to fix this (and what is the cause of the poor compression, or do i need to find a different engine to swap. Thank you in advance for any advice/ideas!

Randy Humfeld