04 vs 04.5

[b.ferrara]

is there any major difference between the 04 and the 04.5 trucks? thanks in advance

 

[Joseph Donnelly]

Most changes were emissions driven for the 2004.5. It was covered in detail in the magazine around winter 2003, and also in the Turbo Diesel Buyers Guide, available on the homepage.

 

[b.ferrara]

Joe thanks for the reply. I always read your arcticles actually the whole book cover to cover. I'm buying a 2004/2004.5 for my son I just couldn't part with my 97' so bought him his own. I have been reading up and asking alot of questions. It seems to be a real nice truck but the guy I'm buying from doesn't know enough about the truck to answer my questions. I will find out everything on Saturday when I drive up to New Hampshire. Thanks again

 

[RVTRKN]

If it's 04.5, it will have HP rating of 325 if it's 04 it can be 305 HP or worse California emissions at 280 (or somewhere around that) look on the valve cover for the info, there were four different versions in 04, 1st~SO, 2nd~California SO, 3rd~HO and 4th 325/600 (Cummins 600)

 

[Wayne M.]

I've noticed that the 04.5 has a engine mounted "fan ring" and a shroud mounted to the radiator. The 03/04 has a different setup. Aren't there internal differences like the piston bowl?

 

[jhenderson]

There are internal engine differences to meet emission standards. When I bought my truck new I made sure to get an 04.5, for the extra HP and torque.I thought I knew best. My truck has been very reliable and a fine performer but I had it to do over I'd get an 04.After 373,000 miles I'd have saved a lot of money with the better fuel consumption numbers and longer duration oil changes.

 

[p-Bar]

04 HO best engine

 

[cerberusiam]

There are major differences between an early 04 and late 04. Big changes internally to the engines, quite a few programming changes also, additonal EGR functionality, a CAT in the exhaust system, exhaust sizing changes.

 

[Bob V]

There are people that prefer the pre 04.5. They feel they got better mpg. I never owned a pre 04.5 personally so I cant give you an opinion on it. I understand the cam profile was changed to have more 'in chamber" EGR for the 04.5+

 

[Ozymandias]

The 4.5 has usually always the 48RE inside. For me that was the Point to buy It over the 03/04, didn't wanted the weak Gearbox.

 

[RVTRKN]

I like the fact that the 04.5 engine was beefed up for the higher EGT, as far as the oil change interval, I changed mine every 3K regardless, but they were free through the dealer were I bought it.

 

[rscurtis]

There are people that prefer the pre 04.5. They feel they got better mpg. I never owned a pre 04.5 personally so I cant give you an opinion on it. I understand the cam profile was changed to have more 'in chamber" EGR for the 04.5+

My signature truck will get better mileage than any PU, large or small, except the new EcoDiesel. I also like the idea of changing the oil at 18K miles and your hands don't even get dirty from the used oil.

 

[p-Bar]

3rd injection event on 04.5 to keep the cat hot = less mileage

 

[AH64ID]

Big differences are pistons, injector spray angle, turbo compressor wheel, and tuning (2 injection events on the 04 vs 3 events on the 04.5, and the 04 generally runs more timing and lower rail pressure).

The 04.5 puts more soot into the oil, even on ones that have been modified (hardware and tuning) to run more like a 04.

The Cam is the same from 03-07, at least as far as I can tell. There have been lots of talk about a cam change, but all the cam builders I have spoken with state they are all the same. The part number is also the same.

I like the fact that the 04.5 engine was beefed up for the higher EGT, as far as the oil change interval, I changed mine every 3K regardless, but they were free through the dealer were I bought it.

The pistons used in 04.5 are far weaker and more susceptible to melting than the 04. Even thou the 04.5 has higher EGT's it runs cooler cylinder temperatures and lower pressures than the 04, one of the reasons the 04 can get better fuel economy.

If you were to tune a 04.5 like an 04 and run them both the same the 04.5 would be at a greater chance for piston damage due to heat than the 04, even thou in stock for the 04.5 runs higher EGT's and has more power.

Really nothing was changed for the higher EGT's, other the reduced cylinder temps via retarded timing.

The valves were changed in 06 due to some failures from the high EGTs in 04.5-05.

The 04 and 04.5 use the same turbine housing, wheel, and center section which means both handle EGT's the same.

 

[RVTRKN]

They changed the valve seat with different material, I don't remember what it is but I have a breakdown of the improvements for the 04.5 that was given to me by my Dodge dealer, they still handle the EGT better than the 04 as you yourself has mentioned. Probably the stock 4" exhaust may have a lot to do with that, I'm no engineer but per Cummins the Cummins 600 was improved on for the higher HP and EGT.

 

[AH64ID]

Yes the valve seats did change for the temp, forgot about those.

It's unfortunate they put the piston they did in those motors, but that's not too hard to change out

 

[b.ferrara]

thanks for all the replies, I will be going to NH to get the truck on Sat. part of me wants the 04.5 part doesn't, I will be happy either way when I figure out which it is.

 

[b.ferrara]

http://www.ebay.com/itm/CUMMINS-DIE...pUhSzFxq2MMQAtPEC%2B0%3D&orig_cvip=true&rt=nc

 

[AH64ID]

It's a 2004.0, probably a 305/555 motor but could be 250/460 or 235/460 as well.

Wow, you got that CHEAP!! 1/2 price.

His answer on the exhaust made me laugh... it does neither.

 

[b.ferrara]

LOL I know, I asked him had a cat or not? he didn't know and I asked him what the drivers side valve cover said, he didn't know. He did tell me that his mechanic told him not the HO motor, I'm not worried, at the very least will spend the weekend in Laconia.