Hi all! Planning to buy a QC 2500 SLT 4x4 3.73 Auto with <75k or so miles in Idaho and don't have anything over 5k lbs to tow. So, a little less hp and torque not significant to me at this point, longevity and mileage is. If I want more umph just for the fun factor, I'd go for chip, etc. down the road. Based on what I've read about the motors the 2004 305hp/555tq is my top choice, but the closest one I've found in a while is a 2004.5 w/70k miles for $23k. (for what I want it only lacks limited slip and a receiver hitch -1st isn't good, 2nd may be a sign of light use). His digital is saying ~15mpg, but claims up to 20 hwy only.

So, now that a few years have gone by, how big a deal is the 2004.5 3rd injection event and the lower mileage? If I wanted a chip, etc does the 2004 3.5" exhaust need replaced with 4" or is it okay for mild mods since it has no cat(not sure that the cat is a major issue). Also, are exhaust brakes available on the 2004 with 48 tranny? Finally, are there any factors that would lean me toward a 2004.5.

Thanks in helping me decide on my 1st serious truck (have had and sold an 85 suburban diesel and 97 expedition without issues and may keep my 95 single cab 4x4 tacoma 2.7, we'll see).

 

15mpg is good for an auto and no limited slip I've never heard of that I thought they only put 11.5 aam rear ends in all these trucks and all of them are limited slip. I don't think I've heard as many injector problems with the 04's over the 04.5 but that is usually people throwing some good amount of hp for these injectors to fail but I personally would go for the 04.5. I'm sure the 3.5 exhasut is all right for mild mods. Why is the cat a major issue for you? and I'm not real sure on the exhaust brake.

 

The 48re is not exhaust brake friendly(will damage it without tranny mods) until the 06 model year.Issue with fliud flo is onde thing that comes to mind.Was 05 not the first year for a cat,convertor.I think it was.

 

The '04.5 has a cat. That was part of the changes when the engine went from the '04 305/555 to the 325/600. In my experience and from what I've read, the '04 will get better mileage than the later MYs. I regulary get 22 out of my 2wd '04. A 4wd will lose about 4 mpg.

 

If I had it to do over again I think I would have got the 04 instead of 04.5 . It is in the shop right now getting it's second set of injectors and another turbo and before anyone says box , the truck is stock . A three week wait the first time and going on two weeks this time , the worse truck I have owned bare none . The Cummins' reliability has left with this poor fuel system just like Fords a very expensive disappointment . They have a poor filter system , poor lift pump and poor injectors all which can be fixed for more money and a canceled warranty .
04.5 has a cat

 

If I had ANY problems out of my 04, I would steer you the other way, but I have been blessed with my 04, good mileage, holds strong all day long, has adapted to mods very well, and in some cases easier to work on (ie electronics, lift pump, etc). I have nothing against the 04.5 ups besides I have driven one. The 03-04s are known for having great mileage and are very dependable like all the other 5.9s. I like i because it was the 1st H.O engine for the 3rd gens.

 

I do NOT have a single complaint about my 04.5






I say go for the 04.5!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

 

I called the local dealer with the vin# and they said it has the 11.5" rear end, but no mention of limited slip so they said it doesn't have it. Do all 11.5s have limited slip? Any way I could tell prior to rear diff service besides getting it stuck?

Still hoping for some good info on the 3rd injector event and how much of an issue it is. I've been looking hard for 2003s and 04s with auto (pretty sure 03 with auto is the 48re - does that actually make it 2003.5?) but no luck yet in QC short box near Idaho. Have found 2 nice 2004.5, but not sure how much of an issue the injector change is an if there are benefits to the 2004.5 over the 2004 other than the extra bit of power. Thanks again for the good info, please keep it coming

 

Over 300k on my 04.5 and no problems and its a work truck that gets worked. Keep up on maintence and you should be fine but of course there are always possibilties happening! Oh and im still on my 1st stock lift pump. I do however have the GDP walbro kit waiting to be installed.

 

You from Idaho or the truck you are looking at is in Idaho. And what part

 

You from Idaho or the truck you are looking at is in Idaho. And what part

 

I'm in Boise/Eagle area, the one I'm looking at is near here as well.

 

My 2004.5 is great I have not had I single problem with it and I get great mileage. I'm convinced that the MPG is based on your environment and your driving style. I 've been averaging around 23mpg for about 25,000 miles now. If the truck has been taken care of it doesnt really matter the year its going to nice.

 

no problems with my 04.5-in 72,000 miles. i average 17mpg in mixed driving. i can hit 20mpg on the highway if i keep the rpm's under two grand.

 

My 04.5 is maintained way better then factory recommended and it is still a headache . 60,000 of the most undependable miles of any truck I have owned , I would tell anyone to run from one . This truck is stock , towed maybe 10,000 of the 60,000 has had good oil and filters its whole life and kept in a garage and babied . All my other diesels use the same oil and fuel with no problems , this fuel system is a joke . I should have got it back today with all new injectors and turbo but the mechanic bent a push rod during reassembly . Not all that hard of a mistake to make before everyone jumps on him and to be honest I have done it myself . So my lemon should be back homeThursday , as dear shot gun season slips away for me , the last time was at the beginning of straw hauling season and I lost over 3 grand on that one .