24v 5.9 Cummins - Winter Project

[CIHTECH]

Min Bore 4.0161

Max Bore 4.0203

Max Taper .003

Max out of round .0014

We attempt to "Plateau Hone" start using a 120 grit stone and end with a 285 grit.

Plateau honing is a sharp peak with a flat top. Once we get the bore clear, is when we switch over to 285 grit stones. Then about 2-4 strokes to flatten peaks left by 120 stones. Use a good magnifier to see what it looks like before & after. Kinda interesting....

Honing speeds of 350 rpm and 1 full stroke per second. 

Certainly not a professional job, but has worked well for us many times. 

[Diesel Doctor]

On 12/25/2025 at 11:21 AM, Gearclash said:

The Ag versions of the 5.9 were generally the lowest rated HP.  The highest I know of was 180 or a little better in the JCB tractors, all the way down to about 85 HP in a CIH 5130.  In the second gen Dodges, that same engine was running from 215 in front of the 47RE automatic up to 245 in front of the NV5600 6 speed.  Then there was a significant bump again after 2002 when the common rail engine was introduced.  I think the last iteration of the 5.9 in a pickup was running 325 HP.  Even in a medium duty truck those engines were set at 220 HP.  

Best information I can find on the net suggests Cummins set the marine versions of the 5.9 up to 480 HP.

Just for fun.  The general public issue Detroit Diesel 6-71 was set for 238 HP in later non turbo versions.  In marine trim, the 6-71 was taken up to an eye watering 485 HP . . . and I have seen a video of a freshly rebuilt marine 6-71 pulling 515 on the dyno.  The TBO at that HP level is pretty short . . . 

How they are rated between Ag, Marine and auto can be a lot different.

The question I have is strength of parts, width of rings and overall ability to survive a 1,000 mile long pull and be ready to do it again, time and time again.

This is why the Detroit's were so popular, you could beat em like a rented mule and they just kept running. Either better parts or a few less HP to keep them together as I like longevity. To me, a running 350 hp beats 480 hp in the shop?

[Sask466]

Update - We decided on getting reman injectors.  There is a place in British Columbia where most injectors seem to be rebuilt - BD diesel. Most all of the diesel shops in the prairies seem to get injectors from there.  
 

The head is going to need new valve seats, which I guessed may be the case.   It’s been a hard 200,000kms (120k miles) for this motor.

Piston squirters/cooling jets:  These blocks have provisions for both types of squirters - One is fed from the main bearing/saddle, and the other is fed from a dedicated jet that mounts directly to an oil gallery in the block. 
 

These newer Dodges use the jet in the picture below:

 

 

 

There is one plug that is broken-off/damage on this motor, apparently it’s not uncommon, especially if heated:

 

So we are wondering if we should just leave it, tap a plug into it (risk of metal filings), or possibly JB weld.  The “proper” fix would be to remove the crank and install a new plug, but that’s a major detour in this project. 
 

Looking for thoughts and ideas.

[Sask466]

Note: Here is what an intact one looks like:

[cumminstinkerer]

Good choice on the BD injectors, they seem to get good reviews for remans, if that plug you are referring to is a piston cooling nozzle you better replace or you will nuke that piston in short order, do not play around swapping to different style pistons or injectors, you open a can of worms that is a ticking time bomb, go back as it was built! That being said I have done piston swapping and injector mods with pretty good success, but I sure wouldn't try to daily that setup, she runs about 1500hp and 75-80 pounds of boost, EGTs will go well into the high 1800s-2000s in a single pass down the track, but shes held up good but for one cracked piston due to timing issues. The common rail engines are not nearly as forgiving as the old mechanical ones and any little mismatch of parts can spell major disaster. I forget what year you said this one was but look the aftercooler over really well, the plastic tanked ones have a habit of blowing out at the seams and will cause exactly what you have there, weird spray patterns and burnt pistons and broken rings, If it is as plastic aftercooler I would either have it pressure tested or just swap it out for an all metal one!

[Sask466]

Pistons going in!

 

[Sask466]

We got the injectors tested - all 6 failed to pass the tests they run.  6 rebuilds from BD are in the mail.

The head is back.  No cracks found.  Some valve seat recession starting.  They replaced all seats and guides.  
 

[B.B.]

I'm following along and would like a picture of the whole truck please

 

Been an interesting read so far. I thought 5.9 cummins were absolutely bulletproof?? 

[Sask466]

Yes, I had a different understanding of the 5.9 Cummins before this project.  I don’t really know what to make of them now.  I don’t think there is much debate about the p-pump 12 valve era engines - they would wear-out most Dodges twice over before they needed major work.

The 2003-2007 era engines I am not so sure on.  This truck was overheated, and perhaps badly.  But I don’t know if that explains it all.  

I feel like the 5.9 was great at 180 to 250hp in pickups, but got stretched thin by the mid-2000’s at 325hp and increasing emissions compromises.  I also wonder if this truck was lugged while pulling a fair bit - it’s a manual and pulled a pretty good sized horse trailer.  

Research on forums indicates these motors can easily run past 1250degF EGT when pulling or hard acceleration.  I find it odd Cummins didn’t put a pyrometer in that ran back to the ECM.  

The head is back on:

[Sask466]

Another observation - how global this Cummins engine is.  I think the block says Mexico, the head says Brazil, other pieces say USA.  
 

I can confirm this is a one owner truck and the bottom end was never touched.  

This seems crazy to me:The bottom rod bearing shell is made in Great Britain and the top shell is made in USA:

 

[dale560]

5 hours ago, B.B. said:

I'm following along and would like a picture of the whole truck please

 

Been an interesting read so far. I thought 5.9 cummins were absolutely bulletproof?? 

They have a reputation of being fantastic but they fail at a more than thought of rate. The older engines were the best. 
I compare them to a cat motor truck owner or a John Deere tractor owner. The motor can fail on any of those three and you will not hear much of a peep about it because of the reputation they bring with them or more so legend status they have. It is also like if you mention most dt 436 engines in the early years had hiccups that IH had to overcome.

[Gearclash]

8 hours ago, Sask466 said:

 I don’t think there is much debate about the p-pump 12 valve era engines - they would wear-out most Dodges twice over before they needed major work.

They had the built in time bomb of the killer dowel pin and internal front cover bolts that worked loose and fell out.  But otherwise they were good engines, especially compared to the competition.  

Some of the 5.9 legend has to do with it being compared to competitive pickup engines that were somewhere on the range of less reliable.  

[dale560]

38 minutes ago, Gearclash said:

They had the built in time bomb of the killer dowel pin and internal front cover bolts that worked loose and fell out.  But otherwise they were good engines, especially compared to the competition.  

Some of the 5.9 legend has to do with it being compared to competitive pickup engines that were somewhere on the range of less reliable.  

The 8.3 in a medium truck have valve seat problems. If pulled to hard and over temp egt they will drop the exhaust valve seats. I have fixed a few of them. In the caseih combines they would blow up because rated speed was to fast until the 1688 or 2188 slowed down engine. 
I follow Dave’s diesel in Utah on Facebook a bit. He always has good info on all those newer pickup diesels. The duramax and slipped timing gears. Ford has some minor stuff on the 6.7 and the Cummins 6.7 he always mentions back two cylinders get oversized 2 thousands because of heat issues.

[Sask466]

I hope my thoughts and opinions on these engines comes across fair - I wouldn’t be afraid to own one.  And if you compare it to the competition back in 2005, I think it should be considered a reliable motor.  

One thing I should give Dodge and the inline 6 credit for - these trucks are WAY easier to do work on than the V8 competition.  It’s still a pretty simple truck and engine to work on.  And that means a lot, because eventually they all fail.  

[sandhiller]

3 hours ago, Gearclash said:

They had the built in time bomb of the killer dowel pin and internal front cover bolts that worked loose and fell out.  But otherwise they were good engines, especially compared to the competition.  

Some of the 5.9 legend has to do with it being compared to competitive pickup engines that were somewhere on the range of less reliable.  

And don't forget the infamous "53" block. 

Had a tendancy to punch windows. 

I have a 24v in a '99 with 345K miles and it has been trouble free.

Worked all it's life and much life left in it, still feel the turbo kick in and pulls strong yet. 

I have replaced the VP44, injectors and a cracked exh manifold is all. 

 

[B.B.]

11 hours ago, dale560 said:

They have a reputation of being fantastic but they fail at a more than thought of rate. The older engines were the best. 
I compare them to a cat motor truck owner or a John Deere tractor owner. The motor can fail on any of those three and you will not hear much of a peep about it because of the reputation they bring with them or more so legend status they have. It is also like if you mention most dt 436 engines in the early years had hiccups that IH had to overcome.

I think you hit the nail on the head there. 

[Gearclash]

38 minutes ago, sandhiller said:

And don't forget the infamous "53" block. 

Had a tendancy to punch windows. 

 

Unless I am really wrong -- the 53 block came after the VE and P pump engines, i.e. the 53 block was concurrent with the VP-44 pump "24 valve".  So far as I know the main problem with the 53 block was a crack that would form in the block allowing coolant to seep out of the cooling jacket.  The 53 block was cast in Brazil and was supposedly missing a reinforcing web internally. In that time frame, the non 53 blocks were cast in Mexico, were not known to crack, and were made of slightly harder iron.  Approximately 1 in 8 blocks were Mexican. 

[sandhiller]

6 minutes ago, Gearclash said:

Unless I am really wrong -- the 53 block came after the VE and P pump engines, i.e. the 53 block was concurrent with the VP-44 pump "24 valve".  So far as I know the main problem with the 53 block was a crack that would form in the block allowing coolant to seep out of the cooling jacket.  The 53 block was cast in Brazil and was supposedly missing a reinforcing web internally. In that time frame, the non 53 blocks were cast in Mexico, were not known to crack, and were made of slightly harder iron.  Approximately 1 in 8 blocks were Mexican. 

Sorry if I wasn't clear

Yes, 53 block was with the 24 valve engines.

I was thinking windows but you could be right with the cracks

Been a long time ago and I learned about them just after I bought my '99

Just glad to see I did not have one. 

Wouldn't imagine there are many (any?) of  those blocks left out there 

[acem]

A friend was  a Dodge dealer mechanic from the late 80s through the early 2000.  He said the 5.9 was a very reliable engine but not perfect.  Never run it out of oil or water.  Overheating kills them.  

The older engines have less power (not turned up as much) and are more reliable.  That is a pattern...

And of course, don't lug any engine under load.

[cumminstinkerer]

@Sask466 man be sure and look that aftercooler over good, being its an 05 it would have been a plastic one from the factory and those crack, leading to loss of boost pressure which then causes high EGT's, can buy aftermarket metal or go to an 06 which was metal from the factory 

[Sask466]

This truck is a 2004.5 as I understand it.  I had a peek at the intercooler - seems to have cast aluminum ends?

Good call though - we should test it.  I still don’t understand how the pistons and head valve seats had that much degradation on them after 200kms/120,000 miles - maybe boost leaks are part of the equation.  

Also someone seems to have been using the condenser as a kick panel while checking oil/washer fluid…

 

[cumminstinkerer]

Yep that is an all metal aftercooler, 04.5 was one of those fun times with stuff changing, I would still pressure test it just to be safe. You take the boost away and these babies get stupid hot stupid fast, will drop valve seats and drill pistons, also if they drop an injector she tries to compensate for it and will up the others delivery, dumb idea, you watch on a computer and do an injector cutout and the others will ramp up! Guess what more heat! if it has a crappy aftermarket air intake system that can be some of the issue too, they leak, and I've proven it on our crappy limestone roads with some Vaseline smeared in the intake before the turbo! Another issue i've seen is the wastegate solenoid failing and dumping all the boost or if the fan clutch or AC clutch wires get dicked it will screw the gate up! usually that throws a code but not always, have also seen crappy batteries or bad cables can cause the wastegate to behave very strange too, just things I've found and will share to help a fella out.

[Sask466]

That’s all info I wasn’t aware of, thank you!

We are installing a pyrometer as well, to help keep an eye on things.

[Sask466]

We got the injectors back in and the valve-train set back on next will be setting the valves.  I just backed off the set screws on the rockers for now so everything is quite loose.  
 

Any tips on timing it?  We are going to roll it over to TDC on #1 and go from there.  I normally just manually spin each cylinder over one at a time, after I ensure I am on the base circle of the cam for intake and exhaust (compression).  Not very sophisticated method, but it’s simple for a dummy like me.  

[cumminstinkerer]

your method is actually the most accurate! hope you installed the injectors per manual, those things can be picky, also hope you put new cross tubes in, if not I would, that is a known leak point. You may have said about them and I missed it. A side note, on the turbo outlet elbow, try to wiggle the elbow and pipe around til they fit really good together the tighten the pip side clamp first, had issues getting my wifes to seal up good, they don't hang just like you would think, and if someone has bent the rod that goes through the hanger down by the trans it makes it even more fun to get those joints to seal up nice.