24-Valve Cummins: years, specs & known problems

By CarWhere Research · Updated

The 24-valve Cummins is the 5.9-liter ISB six used in Dodge Ram 2500 and 3500 pickups from mid-1998 to early 2007. The 1998.5–2002 version uses the Bosch VP44 rotary pump at 215–245 hp; the 2003–2007 common-rail version reached 325 hp and 610 lb-ft by 2005.

Midway through the 1998 model year Dodge switched the Ram's 5.9-liter Cummins to a four-valve-per-cylinder head, keeping the 359-cubic-inch displacement and 4.02 × 4.72-inch bore and stroke. The 1998.5–2002 engines use the electronically controlled Bosch VP44 rotary pump and were rated from 215 hp to 245 hp, with the strongest High Output version making 505 lb-ft.

For 2003 the third-generation Ram got a high-pressure common-rail 5.9 with a Bosch CP3 pump, multiple injection events and a strengthened block, climbing to 325 hp and 610 lb-ft for 2005–2007 before the 6.7 took over in mid-2007. The VP44 engines are known for the cracked '53' block casting and pump failures linked to weak lift pumps; the common-rail years have one engine-related recall.

24-Valve Cummins at a glance

Cummins 5.9L ISB 24-valve turbo diesel I6 (Dodge Ram, 1998.5–2007): model years, fuel and peak Stellantis-published output by version
EngineModel yearsFuelPeak hpPeak torque (lb-ft)Documented problemsRecalls
1998.5–2002 24-valve ISB (Bosch VP44)1998.5–2002Diesel24550530
2003–2007 5.9 common-rail2003–2007Diesel32561001

CarWhere lists 3 documented problems and 1 NHTSA recall for the 24-Valve Cummins, each with a source. Part of the 5.9 Cummins family.

1998.5–2002 24-valve ISB (Bosch VP44)

Second-generation Ram 24-valve with the electronically controlled Bosch VP44 rotary injection pump.

1998.5–2002 24-valve ISB (Bosch VP44) specifications

1998.5–2002 24-valve ISB (Bosch VP44): design facts (1998.5–2002)
SpecificationValue
Displacement5.9 L (359 cu in)[1]
Bore × stroke4.02 in × 4.72 in[1]
Valvetrain24 valves (4 per cylinder)[1]
Injection pumpBosch VP44 electronic rotary pump[1]
TurboSingle Holset[1]
EmissionsCatalytic converter; EGR on California (CARB) trucks[1]

1998.5–2002 24-valve ISB (Bosch VP44) horsepower and torque by year

1998.5–2002 24-valve ISB (Bosch VP44): Stellantis-published horsepower (hp) and torque (lb-ft) by model year and application
Model yearsApplicationHorsepower (hp)Torque (lb-ft)Source
1998.5–2000Automatic215420[1]
1998.5–2000Manual235460[1]
2001–2002Standard output235460[1]
2001–2002High Output505 lb-ft at 1,600 rpm245505[1]

"—" means we could not confirm the figure from a primary source.

Which vehicles have the 1998.5–2002 24-valve ISB (Bosch VP44)?

Models and model years offered with the 1998.5–2002 24-valve ISB (Bosch VP44)
ModelModel yearsNotes
Dodge Ram 2500 / 3500 pickups1998.5–2002

1998.5–2002 24-valve ISB (Bosch VP44) problems and what to check

Cracked '53' block casting (1998.5–2001)

Major repair

Some blocks from one casting source can crack along the side of the water jacket. Affected blocks have the number 53 cast into the side. Not every 53 block fails, but a crack means a block replacement or repair.[1]

Symptoms

  • External coolant leak on the side of the block
  • Coolant level dropping with no obvious hose leak

Check before buying

  • Look for a cast '53' on the side of the block
  • Inspect the block side for coolant seepage or repair epoxy
  • Pressure-test the cooling system

VP44 injection pump failure tied to low lift-pump pressure (1998.5–2002)

Moderate

The VP44 is cooled and lubricated by the fuel passing through it, so weak supply pressure from the factory lift pump is widely linked to pump failure. Low-mileage VP44 failures are often traced to fuel starvation rather than normal wear.[2]

Symptoms

  • Hard starting or stalling
  • Loss of power, especially under load
  • Timing-related fault codes such as P0216

Check before buying

  • Gauge fuel pressure at the VP44 inlet, key-on and under load
  • Ask whether the lift pump has been upgraded
  • Ask for VP44 replacement records

Killer dowel pin (KDP) in the timing gear housing (1998.5–2002)

Major repair

A small steel dowel that locates the timing gear housing can work loose and fall into the gear train. If it does, it can damage the camshaft, crankshaft and injection pump gears. The usual preventive fix is to remove the front cover and tab or retain the pin in place; aftermarket kits exist for the job.[1][3]

Symptoms

  • Usually none before it lets go
  • Ticking or clatter from the front of the engine
  • Sudden loss of timing and engine damage if the pin enters the gears

Check before buying

  • Ask whether the KDP has been tabbed or fixed and get a receipt
  • Budget the front-cover job if there is no record
  • Listen for front-of-engine noise at idle

2003–2007 5.9 common-rail

Third-generation Ram 5.9 with high-pressure common-rail injection, a Bosch CP3 pump and a strengthened block with a bedplate.

2003–2007 5.9 common-rail specifications

2003–2007 5.9 common-rail: design facts (2003–2007)
SpecificationValue
Fuel systemHigh-pressure common rail with Bosch CP3 pump; electronically controlled injectors with multiple injection events[1]
StructureStrengthened block with a bedplate[1]
EmissionsCatalytic converter and EGR, varying by year[1]
Successor6.7L Cummins from mid-2007[1]

2003–2007 5.9 common-rail horsepower and torque by year

2003–2007 5.9 common-rail: Stellantis-published horsepower (hp) and torque (lb-ft) by model year and application
Model yearsApplicationHorsepower (hp)Torque (lb-ft)Source
2003–2004Standard (non-California)250460[1]
2003–2004California (CARB)235460[1]
2003–2004High Output305555[1]
2004.5All325600[1]
2005–2007All610 lb-ft at 1,600 rpm325610[1]

"—" means we could not confirm the figure from a primary source.

Which vehicles have the 2003–2007 5.9 common-rail?

Models and model years offered with the 2003–2007 5.9 common-rail
ModelModel yearsNotes
Dodge Ram 2500 / 3500 pickups2003–2007Replaced by the 6.7 during the 2007 model year

2003–2007 5.9 common-rail recalls

NHTSA safety recalls related to the 2003–2007 5.9 common-rail (campaign numbers link to NHTSA)
NHTSA campaignReportedVehiclesSummary
03V0332003-022003 Dodge Ram 2500/3500 with the Cummins diesel and a manual transmissionIdle speed could stay elevated after extended cruise control use, which can reduce braking effectiveness. Dealers reprogrammed the Cummins engine controller.

Related Ram, Jeep and Dodge research

Confirm a vehicle really has the 24-Valve Cummins.

The engine a Ram left the factory with is part of its build record. The CarWhere Ram build sheet reconstructs factory colors, options and packages from licensed VIN-level build data — availability is checked free, and it is $9.99 only when detailed build data is found for that VIN.

Ram build sheet by VIN

Frequently asked questions

What years is the 24-valve Cummins?

Dodge Ram 2500 and 3500 pickups from mid-1998 (1998.5) through early 2007. The 1998.5–2002 trucks use the VP44 pump; the 2003–2007 trucks are common rail.

Which 24-valve Cummins is best?

It depends on use. The VP44 trucks are simpler but have the 53-block and VP44 concerns; the 2005–2007 common-rail trucks are the most powerful 5.9s at 325 hp and 610 lb-ft.

How do I know if I have a 53 block?

Look on the side of the engine block for a cast number 53. These blocks, found on 1998.5–2001 engines, can crack along the water jacket.

Why do VP44 pumps fail?

The VP44 relies on diesel flowing through it for cooling and lubrication, so low lift-pump pressure is the most commonly cited cause. Checking fuel pressure at the pump inlet is the standard test.

How much horsepower does the 24-valve Cummins make?

215–235 hp for 1998.5–2000, 235–245 hp for 2001–2002, 235–305 hp for 2003–2004, and 325 hp with 600–610 lb-ft for 2004.5–2007.

Sources

Ratings are Stellantis-published figures as cited; descriptions are CarWhere’s own summaries of the sources below. Repair costs appear only where a source states them and vary by shop and region.

  1. Cummins Diesel: The Engine That Powers The Ram (May 2015) — Diesel Army
  2. How to Check Lift Pump Pressure on a 24 Valve Cummins and Why It Matters — Diesel Power Products (secondary reference)
  3. Cummins History, Lesson 2: '94-'98 5.9L (Feb. 2019) — Driving Line

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Independent reference compiled by CarWhere — not affiliated with or endorsed by Stellantis or Cummins Inc. Ram, Jeep, Dodge, HEMI, SRT, Hellcat, Hurricane and the model names are trademarks of their owners.