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Cat C13 Engine

Cat C13 Engines For Sale


Yellow Caterpillar C13 Engine for Sale

Like so many other diesel engines available at the beginning of the 21st century, the CAT C13 was an emissions-friendly replacement for its proven yet dated predecessor, the C12. But while the C12 was lauded for its fuel economy and million-mile durability, to many, the CAT C13 never lived up to the hype. That said, thanks to debuting Cat’s ACERT technology, the C13 did meet significantly more stringent NOx emission standards that went into effect in 2004. It’s also worth noting that, although it would end up being part of the company’s downfall in the on-highway engine market, Caterpillar was able to adhere to the new NOx standards without the use exhaust gas recirculation (EGR)—a technology that had been extremely troublesome for other engine manufacturers.

The CAT C13 was employed in a myriad of applications, from Class 8 and medium duty trucks to power generation, mining, and construction. And with various power ratings offered (including 525 hp in motorhome form, an engine which ironically came with a lower capacity oil pan and that called for shorter oil change intervals), the C13 was placed in service in virtually every sector of the economy from 2003-2010. But even though it was a cleaner-burning and more powerful engine than the C12, the C13 was plagued by emissions equipment issues. The introduction of the diesel particulate filter (DPF) in 2007—along with the corresponding regeneration system (used to clean it)—only amplified the C13’s emissions-related problems. We’ll elaborate more on this in a bit.

What Is ACERT?


CAT ACERT Logo for Caterpillar C13 Engine for SaleCaterpillar’s Advanced Combustion Emissions Reduction Technology, abbreviated as ACERT, was the company’s series of solutions aimed at curbing NOx emissions. More than $500 million was invested in the technology, which was expected to be adaptable for future emissions standards and future engines. In 2003, Cat billed its ACERT technology as being capable of reducing both NOx and particulate matter (PM) emissions at the point of combustion rather than relying on exhaust gas recirculation (EGR) like its competitors were doing. The air management side of ACERT for the CAT C13 included sequential turbocharging (also known as compound turbocharging), which was employed not only to force more air into the combustion chambers (remember EGR is used to lower combustion temperature in-cylinder), but denser air as well. Unfortunately, while Cat’s sequential turbocharger arrangement looked good on paper, out in the real-world its system was anything but responsive (i.e. it was notably laggy). Caterpillar’s variable intake valve actuation technology was also utilized on the C13, working in concert with the camshaft to further lower NOx emissions while at the same time improving fuel efficiency.


Combustion And Aftertreatment With ACERT

Replacement Options for Caterpillar C13 Engine for SaleIn-cylinder, multiple injection events could be accomplished on each power stroke thanks to Cat’s use of an advanced version of Mechanically actuated Electronically controlled Unit Injectors (MEUI). With the lift pump supplying 80 to 90 psi worth of fuel supply pressure to the rail in the cylinder head, the camshaft actuates a rocker arm to fire each injector, with the injectors being controlled via ECM. The ECM also commands variable valve actuation, which provides for optimization of the intake valve timing for improved horsepower, torque and fuel economy while decreasing emissions at the same time. Downstream of the engine, a flow-through diesel oxidation catalyst (DOC) was part of the early exhaust aftertreatment equation on the Cat C13.

Pre-ACERT, “Bridge Engines”

Bridge Engine of Caterpillar C13 Engine for SaleBefore Cat’s ACERT technology was ready for production, a Band-Aid of sorts was implemented for the C13. To fill the gap between the end of C12 production and the C13 ACERT that was coming, “bridge engines” were offered. The backstory here is that in 1998, after having been found to have knowingly implemented engine control software (i.e. defeat devices) that produced NOx emissions beyond allowable limits, Caterpillar—along with other engine manufacturers—signed a consent decree dictating that the company would meet the 2004 emission standards 15 months ahead of the deadline. However, Cat’s ACERT technology was not ready by the 2002 deadline, so bridge engines, which incorporated some of the components of ACERT, were sold instead.

These CAT C13 “bridge engines” were certified above the new 2.5 g/bhp-hr NMHC+NOx standard and were subjected to nonconformance penalties to the EPA. The bridge engine run was short-lived, as ACERT engines were in full production by January of 2003, but due to their lack of emissions equipment these variants of the C13 are said to be some of the most reliable C13s ever built.

The Emissions-Solving Yet Downtime-Inducing Dilemma

Particulate Filter of Caterpillar C13 Engine for SaleThough the early C13 ACERT engines (produced from 2003-2006) were mechanically sound, they are perpetually plagued by intake valve actuator (IVA) and precooler failures. However, the 2007-2010 versions (and namely those with serial numbers beginning with “LEE”) typically experience the biggest problems the C13 line faced. These model year C13’s, which represent the final engines Cat built for on-highway use, went unchanged structurally but were laced with some of the most complex emissions-scrubbing technologies the company had ever implemented.

Among the emissions equipment aboard the ’07-’10 C13 was Clean Gas Induction (CGI), a Diesel Particulate Filter (DPF), and the Cat Regeneration System (CRS), which introduced the highly problematic Aftertreatment Regeneration Device (ARD) head. Each of the aforementioned systems would bring its own set of pitfalls into the fold, including (but not limited to) DPF, CRS, sensor, injector, and fuel line failures.

Believed by many to have been rushed to market in order to meet the EPA’s 2007 particulate matter (PM) emissions standard (which required engines to emit 90 percent fewer PM than was required in 2006), the C13 “Regen Engines” (as they are often referred) were the source of all sorts of litigation and at least half a dozen proposed class-action lawsuits. Many allege that Caterpillar was apprised of its C13 reliability problem but continued to produce the engines anyway—all while planning to pull out of the on-highway market by 2010.

Unique Features Of The C13

Yellow Caterpillar C13 Engine for Sale on top of a Black PlatformCat’s C13 is different from most ACERT engines in the company’s lineup, though it does have a fair amount in common with its C11 sibling. First and foremost, the C13 makes use of an external oil pump (unlike the C15, for example). The C13 also tends to run at lower oil pressure than any other Cat engine, with just 20-psi commonly being observed at idle (which is considered to be within spec). Between the block and head, there is no spacer plate (unlike what you’ll find on a C15) and the C13 also utilizes an automotive-like head gasket. As for the C13’s valvetrain, the pushrods are located in the block, with the lifters bolted on top of the deck under the cylinder head. Needless to say, when a C13 suffers a lifter failure, cylinder head removal is mandatory in order to address it. And while not exactly being unique to the C13, it is celebrated for its containment of fluids (i.e. it isn’t prone to developing leaks as easily with age, as most engines in its class do). Much of this is attributed to the C13’s being assembled with thick, high-quality gaskets.

Common C13 Problems And Failure Points

Caterpillar C13 Engine for Sale on an EquipmentBeyond its emissions system shortcomings, the C13 has its fair share of pattern problems, and its biggest issues arise when it overheats. Overheating a C13 often results in a cracked cylinder head, with a hairline crack typically occurring between an injector and an exhaust valve. This leads combustion gases entering the cooling system and/or coolant infiltrating the combustion chamber—not to mention the fact that it’s an expensive repair. The C13’s wet sleeve cylinder liners were also single O-ring pieces (by comparison, C15 liners incorporated three O-rings). With age, the single O-ring eventually fails and allows coolant to mix with engine oil. Most of the C13 failures we see here at Big Bear Engine Company are listed below:

  • Cracked Cylinder Head (often due to overheating)
  • Oil Consumption And Extreme Blow By
  • Cracked or Leaking Precooler
  • Diluted Engine Oil Due to Precooler Failure
  • Spun Crankshaft Bearings
  • Outright Crankshaft Failure
  • Scored Pistons and Cylinder Liners
  • Connecting Rod Bearing Failure
  • Over-Fueling
  • Roller Lifter Failure
  • Dropped Valves

The Big Bear Remanufacturing Process

Back View of Yellow Caterpillar C13 Engine for Sale on top of a Wooden PlatformIf a customer’s C13 is unfortunate enough to suffer a serious internal engine failure but at the same time is fortunate in that many of the engine’s external components can be retained and reused, a remanufactured C13 long block is a great solution. Coincidentally, a reman long block is about as financially feasible as replacing a CAT C13 engine gets.

When we remanufacture a C13 at Big Bear Engine Company, our team of machinists and engine builders perform a full core tear down, cleaning, inspection, and also handle all the machine work before it leaves our care. This process guarantees that each engine leaves the Big Bear facility in perfect running condition every time.

Of crucial note in the Cat C13 reman process is that all of our remanufactured long blocks are built with a mixture of both remanufactured and new parts. We do not recondition or refurbish old engine parts. Instead, we comprehensively rebuild your C13 back to OEM Caterpillar specs.

Comprehensive Cleaning

Side View of a Rusty Yellow Caterpillar C13 Engine for Sale on top of a Platform

In an effort to avoid early failure of both parts and the C13 engine itself, we remove all impurities by stripping the block, head, rods, and camshaft, all of which are subjected to an extensive and meticulous cleaning process in a chemical jet wash or hot tank.

The Crankshaft

Crankshaft of a Caterpillar C13 Engine for Sale

Factory C13 crankshafts are precision machined to exact tolerances, polished for reduced bearing and oil resistance, and magnafluxed to check for cracks. After that, the crankshaft is inspected by our quality control department.

Cylinder Head

Cylinder Head of a Caterpillar C13 Engine for Sale

To both guarantee a proper sealing surface with the block and achieve a finish that is compatible with the latest gasket materials on the market, the cylinder head is resurfaced after passing initial inspection. Valve height is mic’d and the head is vacuum-tested to ensure that precise valve sealing is present.


Cylinder Block of a Yellow Caterpillar C13 Engine for Sale Each C13 block is carefully inspected for cracks or other signs of damage. To eliminate distortion once the cylinder head is fastened to the block, the cylinders are bored and honed to precise tolerances. This process reduces the causes of engine blow-by considerably. All block surfaces are machined and then inspected to achieve an ideal finish.


Camshaft of a Caterpillar C13 Engine for Sale

The camshaft is inspected and precisely machined to ensure it provides the correct lift. All lobes are measured with a micrometer to make certain that OEM tolerances are adhered to.

Connecting Rods

Connecting Rod of a Caterpillar C13 Engine for Sale Each connecting rod is carefully analyzed for signs of bending and/or twist. From there, each unit is cleaned and then machined to OEM specifications. That process is followed with all rods being honed to their usual diameter of original equipment, which provides for even distribution of stress across the rod bearing.

New Parts

Gasket Kit Parts of a Caterpillar C13 Engine for Sale Fresh pistons and rings, bearings, wet cylinder liners, gaskets, and seals come standard on all reman CAT C13 long blocks. These brand-new parts ensure dependable performance and reliability throughout the life of the engine. The new parts employed in a Big Bear long block are a combination of OEM and aftermarket components.

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Please fill out the form below with your information and request. A member of our staff will be with you shortly.

Further Insurance

Side View of Yellow Caterpillar C13 Engine for Sale Tied with a Thick Black Rubber BandWearable parts are replaced in every single engine we build at Big Bear, and all C13 core material is inspected and examined against the original specifications to certify correct dimensional tolerances. In the end, the goal of remanufacturing an engine is to restore it to a state that is as close to new as possible. Alternate parts are either new or requalified, and if new the parts are produced using the exact same manufacturing process(es) employed on the original engine. All testing is performed according to manufacturer specs and original production standards.

C13 Long Block Parts List:

  • Block
  • Cylinder Head (loaded and complete)
  • Crankshaft
  • Connecting Rods
  • Sleeves
  • Pistons and Rings
  • Camshaft
  • Lifters and Followers
  • Intermediate Cover
  • Timed Front Gear Group
  • New Upper and Lower Gasket Set
  • All Required Lower Gaskets and Seals
  • 1-Year Warranty

*Note: We can provide a new oil pump, oil cooler, water pump, turbos, injectors, and fuel pump for an additional cost with the long block, but these components will not come assembled to the engine.

**1-Year Warranty: First 6 Months Parts & Labor, Second 6 Months Parts Replacement Only. Ask your sales representative for a full copy of our manufactured long-block warranty.

CAT C13 Applications:

  • Class 8 Trucks
  • Medium Duty Trucks
  • Firetrucks
  • Motorhomes
  • Ag Tractors
  • Aircraft Ground Support
  • Chippers and Grinders
  • Combines and Harvesters
  • Compactors and Rollers
  • Power Generation
  • Underground Mining
  • Loaders, Cranes, and Crushers

CAT C13 Spec

Engine Data

Production2003-2010 (on highway)
ConfigurationInline-six (I-6)
Displacement12.5L (763 ci)
BlockCast-iron with single O-ring wet cylinder liners
HeadCast-iron, cross-flow, 6 torque-to-yield bolts per cylinder
PistonsOne-piece steel, full-floating
Compression Ratio17.0:1 to 17.3:1
ValvetrainSingle cam with roller lifters, overhead valve
AspirationTurbocharged, precooled, and aftercooled, single turbo (non-ACERT “bridge” engines), sequential turbo (ACERT engines) with electronic wastegate
Injection SystemMechanically actuated Electronically Controlled Unit Injectors (MEUI) (camshaft actuated, electronically controlled)
Emissions EquipmentACERT with variable intake valve actuation and diesel oxidation catalyst (’03-‘06), ACERT with variable intake valve actuation, CGI, DPF and CRS (’07-‘10)
Horsepower305 to 525 hp (depending on application)
Torque1,350 lb-ft to 1,750 lb-ft (depending on application)
Governed Speed2,100 rpm
Weight1203-1272 mm (47.2-50.1 in)

Give us a call today at 844-340-4114 for immediate sales and support for the Cummins 4BT, Cummins 6BT, 6CT, ISC, 855, QSB 4.5 L or CAT 3306. If you have any questions check out our FAQ Page. We are always ready to help or just listen to your crazy off-roading adventures!

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