My truck was down, so I borrowed my FIL's 05 Duramax to pull my velocity to the shoot out at LOTO.

1, the mileage sucked AZZ! The truck had gobs of power, but it got about 8mpg......is that normal? My f150 does better then that, but doesn't have near the power obviously.

2. It had some kinda of horrendous knock/rattle from the steering column. Any clue what could be going on there? I'd like to fix it for him, since he let me borrow the truck. In the little research I have done, it seems to be the intermediate steeling shaft I am guessing... Anyone changed, of fixed one of these? doesn't seem like a bad job. The steering/suspension is pretty tight, but its got a bad knock/rattle that sounds like its coming directly inside the steering column. The truck only has 93K on the clock.

1. My '04.5 LLY DMax pulled down 11 MPG towing 8,200 lbs. to LOTO from IL.

2. The stealer took care of the intermediate shaft problem so I never touched it. However, given your description and mileage, I'd look over the entire front suspension closely. Tie rods, idler arm, pitman arm, ball joints, etc.

How did it tow and how did you tow with it? Did you set the torque converter lock and set it to cruise control? Was it downshifting on the hills at all? When was the last time the fuel filter was changed? 8 mpg is a little low for pulling that boat.

Your friend isn't maintaining his truck very well. Steering shaft is about a 300 fix. 8 mpg??? Something wrong there.

Wannabe

Your Ford was broke and you complain about a running 10 year old GM?

Not complaining. I just figured a diesel should do better then 8mpg towing maybe 7K. Like I said the truck ran like a raped ape, just thought the MPG would be better....maybe not, I dunno....that's why I asked.

My FIL told me after I talked to him this morning, that the dealer has replaced the intermediate shaft already at 65K miles. In doing some reading looks like you can grease it?

He actually does take pretty good care of it, and rarely drives it (maybe 4K.year), it just started making the noise, and he is going to take it in, if we can't figure it out ourselves. Suspension, and steering are tight, no issues there. This is strictly like its inside the column/behind the dash.

Ask him when the last time the fuel filter was replaced. You need to replace the fuel filter on these at least every other oil change. Earlier duramax's at least every oil change. Also, the truck may feel like it runs awesome but it still could be low on power. If it is getting 8 mpg towing, I would have the injector balance rates checked. The early ones had injector issues.

early 04's were the last of the injector issues. 04 1/2 and newer didnt have the injector issues. get a GM fuel filter and GM air filter for it. i bet they hvent been changed in a long time. put a intermediate steering shaft in it that will get rid of the clunking. my 04 with a tuner and exhaust used to get 20ish towing a 28 pantera. the 05 should be at least 14-15mpg

My 2004 get about 10 pulling 11k boat trailer....

steering shaft is very known easy fix.

also the classic body trucks need front wheel bearings... they sell then whole hub, abs snesor, and all for 200 ish bucks 4 bolts and done.

04.5 just started the wiring harness issues lol, and the twice as expensive never in stock injectors