Engine difference between 02-03 5.9's?

[BTackett]

I know the body styles changed drastically but what is the actual engine changes? I am getting stories about smog, different injector pumps etc and different power band rpm's.



What actually is the difference between the 2002-2003 trucks with the 5. 9?



I didn't know where to really post this and did a search on the 2nd gen board and did not get any results.

 

[MickeyMiller]

'03 vs '02: Different pump and injectors... no smog stuff on either. If it's an HO, you get more power. Quieter, broader power band. Both have suspect lift pumps.

 

[Prairie Dog]

Huge differences including different block and internals, head, turbo and the introduction of Common-Rail fuel injection. The RPM range was extended to 3200 to make better use of the new 3. 73 gearing. This is just a small sample of the changes and I'm sure others will chime up with much more. You are correct on the lift pump problem. I have no idea why they continued to use that weak design.

 

[dclassens]

everything under the hood is 100% different.

 

[HBarlow]

The 2003 model is the first of the Generation III platform which marked the introduction of the HPCR or high pressure common rail engine. In lay terms, the injectors became electrically operated "valves" which allow passage of fuel under high pressure from the common rail where pressurized fuel is stored by the high pressure pump.

Previous 24 valve engines used a complex electronic injection pump which selected the cylinder to be fed at the proper time. HO versions of HPCR engines also began using pistons, valves, and rings capable of sustained operation under higher exhaust gas temperatures in order to produce greater hp and torque.

Many improvements were included in the Gen III trucks such as four rear opening doors in quad cabs, quieter operation, smoother ride, and better brakes as well as the HPCR engines.

The engine redline was not changed. It is the same as the earlier 24 valve engines.

 

[Bill Stockard]

For a review of the third generation with a model year to model year change list, see the TDR Buyer's Guide, beginning with page 14.



Bill

 

[BTackett]

Thanks for the info. Will the buyers guide show mpg on the two different years? I will look into it. I am having a hard time finding a 98. 5-2002 model and see more of the 03-04 models out there.



thanks again.

 

[rscurtis]

IMO, the '98. 5 to 2002 5. 9 is the least desirable choice. You would be better off with a 12 valve. The '98. 0 12V is considered very desirable.



The CR engine in the 2003 -04 trucks is light years better than either choice, and there is no comparison chassis wise with a 2nd generation truck. You could have some front end issues that were not a problem on the 2nd gen. , but the finish, brakes and 17" wheels are a big improvement over a 2nd gen. truck. I have owned both a '95 and an '03, there is no comparison.



Don't be fooled into thinking you need the "600" engine, that little bit of extra power will cost you in fuel economy and more frequent oil changes. The "555" engine also has simpler programming.

 

[JGoss]

I like my 04. 5', but the sound of an 89'-02' can't be beat.

 

[CPavlic]

I wouldnt trade my truck for any other model. Yeah the pumps are the weak link, but get a good after market lift pump and fuel pressure gauge and not worry about it. While the newer trucks are a little more refinned and start with higher power, the injector and sanding issues scare me. Just my two cents worth