Best diesel trucks.....fact or fiction ???

[Dreamer]

Here is part of an article I copied from a diesel truck magazine article about the best diesel trucks. What do you think ?



2003 to 2004½ Dodge Ram 2500 and 3500

Common-rail injection ushered in a new era of technological advancement for the famed inline-six Cummins engines that have been offered in Dodge pickups since the ’89 model. The new powerplants burn cleaner and make more power—yet they are still the simplest of the modern diesels. Unfortunately, the change to ultra-low sulfur fuel combined with increased injection pressures has led to reduced injector life in new diesels. When ’05-and-later 5. 9L Cummins engines have malfunctioning injectors, they can cause melted pistons, which can ultimately lead to a full engine rebuild. But the earlier common-rail Dodges (’03 to ’04½) seem to give the driver much more of a warning (in the form of a bunch of white smoke exiting the tailpipe) before they pop any pistons. Over-the-road haulers will want to look for cast-iron, NV5600 six-speed-equipped dualies from this era for their next tow rig.

 

[rscurtis]

I would agree with that, but the range should be '03-'04, not '04. 5, which was the start of the "600" engine with its third injection event, reduced fuel economy, and dirty oil.

 

[Prairie Dog]

I think it was just as common (or uncommon) for first and second gen Cummins to burn a piston with a bad injector.

 

[Dreamer]

I would agree with that, but the range should be '03-'04, not '04. 5, which was the start of the "600" engine with its third injection event, reduced fuel economy, and dirty oil.

I read the article to mean up to 2004 1/2 meaning up until the "600" engine.

 

[BrianJ]

I read the article to mean up to 2004 1/2 meaning up until the "600" engine.

I read it the same way rscurtis sees it, that they are including 4. 5's in their recommended category. The sentence before even starts with '05 as the ones to avoid. Semantics really, but I agree with rscurtis and they should have said '03-'04 to accurately bring their point accross.

 

[rscurtis]

I think it was just as common (or uncommon) for first and second gen Cummins to burn a piston with a bad injector.

Of course it is possible, but it will give plenty of warning. The bad cylinder on a pump-line-nozzle system can only get as much fuel as was intended for that cylinder. When a CR injector goes bad, it can deliver the full output of the entire fuel system.

 

[JJPage]

The reason the 5. 9 04. 5+ years may melt a piston easier than 03/04 CR's, is the narrower spray angle they used when straying away from the re-entrant piston bowl. The 6. 7s reverted back to the re-entrant design.

Another reason I love my 03!

 

[Dreamer]

Good information. How can you tell at a glance which engine a 2004 has? Can anyone post a picture of the two engines? Thanks.

 

[AH64ID]

Easiest way to tell is the valve cover placard, 325 hp is an 04. 5 235/250/305 is 04. Visually they are nearly identical.

 

[JJPage]

Good information. How can you tell at a glance which engine a 2004 has? Thanks.

If it's For Sale, it's most likely an 04. 5+ :-laf:-laf:-laf



Jess

 

[rscurtis]

The '04. 5-'07 also have a 4" exhaust system with a catalyst.

 

[cerberusiam]

I guarantee if you put a bad injector in an 03-04 and drive it you WILL have a melted piston. Re-entrant bowl or not, too much fuel will kill it and that doesn't change.



The 03-04's were consistently lower HP and lower injection pressures with arguably a bit better fuel. However, by the time the 600 engines came along more than few had been melted by pushing too much fuel with pressure and duration.



More than anything,m the emissions design in the 600 engine hurts it the most. The cam timing, injection timing, and high late event cylinder temps are much harder on the components.



The whole article is a matter of perception and the authors experience. Makes for good reading but not really a valid blanket statement.

 

[Shadrach]

Good information. How can you tell at a glance which engine a 2004 has? Can anyone post a picture of the two engines? Thanks.

The 04. 5 and new also have the fan shroud mounted to the engine ( for tighter clearances ) instead of the older rad mounted style. If the build date of the truck is after Jan 1 2004 then it is an 04. 5 model. In other words you want the truck to be built in either 2002 ( the early automatics were only 250 HP ) or during the 2003 calendar year. Jan 1 is the emission change date. Shad

 

[TCDiesel]

Yep, So the 03/04 503 has 8 holes that run 2-3K less pressure then the 04. 5/07 325 505 5 holes,its the emissions that the 325 gets hurt by. If any CR injector hangs it gonna suck up your wallet, regardless of Piston style. Running higher pressure May add wear over the coarse of it's life (Injector), running extreme pressures will destroy Injection component's or worse.



If you were running 325 vs the HO/SO the difference would only be a matter 10,000-30,000 miles term life.



I do favor the 03/04 its just a small advantage, the OP being the biggest advantage, cooler Cylinder temps and cleaner oil with extended change intervals.



The LML Duramax and the new scorpion Ford Run much higher injection pressure 3/5K more and at $500/600 replacement injector X 8 = $4800 ouch.

 

[Dreamer]

Yep, So the 03/04 503 has 8 holes that run 2-3K less pressure then the 04. 5/07 325 505 5 holes,its the emissions that the 325 gets hurt by. If any CR injector hangs it gonna suck up your wallet, regardless of Piston style. Running higher pressure May add wear over the coarse of it's life (Injector), running extreme pressures will destroy Injection component's or worse.



If you were running 325 vs the HO/SO the difference would only be a matter 10,000-30,000 miles term life.



I do favor the 03/04 its just a small advantage, the OP being the biggest advantage, cooler Cylinder temps and cleaner oil with extended change intervals.



The LML Duramax and the new scorpion Ford Run much higher injection pressure 3/5K more and at $500/600 replacement injector X 8 = $4800 ouch.

Geeze, does anyone else think this sounds like diesel geek speak? Sorry but as a nube, I hardly know what this means. Can someone translate? :-laf

 

[JJPage]

I guarantee if you put a bad injector in an 03-04 and drive it you WILL have a melted piston.

Cerb, why would anybody put a bad injector in their 03/04?:-laf

I was just thinking because of the narrower spray angle, blowing into the center of the piston, rather than to the outside of the bowl, if an injector solenoid hung open, then it may burn a hole into the piston sooner because of the concentrated spray? I really don't know, but it seemed logical to me.

Geeze, does anyone else think this sounds like diesel geek speak? Sorry but as a nube, I hardly know what this means. Can someone translate? :-laf

Todd is explaining the difference in the injector styles and stock rail pressure between the years. 03/04 injectors have 8 holes and operated at a lower pressure than the 04. 5+ injectors that have 5 holes. Then he kind of started to ramble a bit unless you are familiar with his jargon, he makes much more sense when you speak with him on the phone. Jess

 

[Dreamer]

[/QUOTE]

Todd is explaining the difference in the injector styles and stock rail pressure between the years. 03/04 injectors have 8 holes and operated at a lower pressure than the 04. 5+ injectors that have 5 holes. Then he kind of started to ramble a bit unless you are familiar with his jargon, he makes much more sense when you speak with him on the phone. Jess[/QUOTE]



Thanks, my wee brain can assimilate that now.

 

[cerberusiam]

Cerb, why would anybody put a bad injector in their 03/04?:-laf



I was just thinking because of the narrower spray angle, blowing into the center of the piston, rather than to the outside of the bowl, if an injector solenoid hung open, then it may burn a hole into the piston sooner because of the concentrated spray? I really don't know, but it seemed logical to me.

Obviously no one intentionally puts a bad injector in, but, the results are the same in either engine. The original quote intimated in a roundabout way that injector failures would produce different results in the seprate configurations. Different symptoms maybe but the results are going to be the same.



I will see if I can find the cross sections of the pistons, but, there is little difference in the HO piston design. The difference that has been shown to consistently cause issues in big power engines is the formation of the piston at the lip of the bowl. The re-entrant bowl has a lip that puts more material over the thinnest portion of the crown, right at the edge of the bowl. The non re-entrant bowl has this lip rwmoves and slightly less material in the crown in this one area. What was happening when timing, duration, air, etc, was not right at high rpms and high HP was the crown was melting faster in the later piston than the early piston.



Ultimately both pistons failed in the same spot but it took one longer than than the other. Even the 03-04 design fails if piston heat soaks and starts puddling from to much cylinder temp and lack of cooling.



The center of the bowl and edges of the piston are actually the heaviest parts. With the gallery cooled pistons the rim of the bowl is the thinnest and where the bulk of the cooling is needed. Spray angles dictate that. The difference of 16 degrees of angle puts the fuel towards the outside of the bowl in both configurations by design.



The typical failures whan an injector goes bad is not a hole in a piston as much as the the whole top starts puddling and scuffing the cylinder. Thats just too much fuel from a hung injector. It doesn't matter what bowl configuration you have its gonna melt the piston.



Torching a hole in a piston is usually from cracking a tip or breaking a piece out of it causing heavy stream of fuel hitting in one spot. Again, it doesn't matter what piston configuration is used failure is imminent.



There is also a pretty good argument the re-entrant bowl has a beter chance of failing than the smooth bowl. In extreme conditions the lip is a starting point for failure under heat soak and once it starts to fail it just accelerates. The smooth bowl has less material to handle heat soak.



Experience has shown that the 04. 5 engines are a bit more sensitive to all things being correct whne it comes to longevity. They are also hampered by emissions and which drives cylinder temps up and additional power.



Its a bit too broad a stroke to point at 1 piece like is done and say this makes it a less desirable unit. There is more than 1 or 2 factors that quantify "best" IMO.

 

[cerberusiam]

LOL, your not the first nor will you be the last to get lost in the nomenclature. Try to simplify it too much and you can't see the forest for the trees in the way. While the operations of an HPCR are pretty simple the implementation, potential effects of changes, introduction of contaminants complicates things to a high degree. It ends up being a mix of metallurgy, fluid dynamics, combustion characteristics, air flow dynamics, and the ever presnt human factor trying to explain whay something works or what happens when you do A or B and not C.



All you can do is ask for clarification. One or two sentences is not near enough to communicate abstract concepts. :-laf