A lot of good medium duty trucks, school buses and diesel pusher motorhomes are still running on a Cat C7. When the engine is worn out, the chassis usually is not, and that is why so many owners look for a replacement instead of a new vehicle. We have a Caterpillar C7 engine for sale, tested, photographed and ready to ship to buyers anywhere in the world.
Want a price now? Send your engine serial number and vehicle details through our contact page or call +1 (209) 733-0882. You can also browse our Caterpillar engines in the shop. You can also go straight to the Caterpillar C7 Engine for Sale product page to see the price.
We only sell engines, so we see a lot of them. The Caterpillar C7 engine for sale is a regular request from owners of Freightliner, Peterbilt, Kenworth and GM medium trucks, from bus fleets and from RV owners who want to keep a good coach on the road.
Below you will find the specs, the vehicles it fits, serial number prefixes, the faults to watch for, how we test and how ordering works.
Where the Cat C7 Came From
Caterpillar built the C7 as the replacement for the 3126, its popular 7.2 litre medium duty engine. The C7 kept the same size and layout but brought Cat’s ACERT approach to meeting the 2004 emissions rules without the cooled EGR systems many rivals used at the time.
On the road, the C7 was sold from around 2003 until Caterpillar left the on highway engine business at the end of the 2009 model year. Off the road it carried on in machines, marine and industrial use, and it was later followed by the C7.1.
That history matters when you shop. A huge number of trucks and buses were built with this engine, so a Caterpillar C7 engine for sale is usually the easiest way to repower one. The mounts, the wiring and the cooling were all designed around it.
Caterpillar C7 Engine Specifications
These are the common on highway figures. Ratings vary with year, software and application, so we always check the data plate before we quote any Caterpillar C7 engine for sale.
| Engine type | Inline 6 cylinder, four stroke turbo diesel |
| Displacement | 7.2 litres (442 cubic inches) |
| Bore x stroke | 110 mm x 127 mm (4.33 in x 5.0 in) |
| Fuel system | HEUI hydraulically actuated electronic unit injectors on most engines |
| Aspiration | Turbocharged, air to air aftercooled |
| Horsepower | About 190 to 360 hp depending on rating |
| Peak torque | Up to about 860 lb-ft on the highest ratings |
| Engine control | ADEM electronic control, 70 pin ECM connectors on most 2004 and later engines |
| Common truck serial prefixes | KAL, SAP and WAX |
| Emissions | EPA 2004 with ACERT, EPA 2007 engines with a diesel particulate filter |
| Cooling | Liquid cooled |
The serial prefix and the arrangement number on the plate tell us almost everything about the build. Send both when you ask about a Caterpillar C7 engine for sale.
Reading the Serial and Arrangement Numbers
Cat engines carry a lot of information on the plate, and it pays to know what you are looking at.
The serial number starts with a three letter prefix followed by five digits. For on highway C7 engines the common prefixes are KAL, SAP and WAX. The prefix tells you the family and the build period. The digits identify the single engine.
The arrangement number, often written as AR, describes the exact set of parts the engine was built with: sump, front housing, flywheel housing, turbo, fuel system and rating. Two C7 engines with different arrangement numbers can need different parts to fit the same truck.
The rating or horsepower setting lives partly in the software. A 190 hp school bus engine and a 330 hp truck engine can share much of the same hardware, but the injectors and the ECM programming are not the same.
When you send us a photo of the plate, we use all three to match the right Caterpillar C7 engine for sale. It saves days of guessing and it stops expensive mistakes.
Signs Your C7 Needs Replacing
Some C7 faults are cheap repairs. A failed ICP sensor or a cracked high pressure oil line can make an engine look much worse than it is. But some signs say it is time to look at a Caterpillar C7 engine for sale.
- Bottom end knock. Usually a bearing failure. Crank grinding, block work and parts add up fast.
- Heavy blow by and oil use. Worn rings and liners mean a full rebuild.
- Coolant in the oil that keeps coming back. A cracked head or block, not just a gasket.
- Low compression on several cylinders. General wear rather than one bad valve.
- Damage after a turbo or valve failure. Debris in the cylinders often scores liners and pistons.
If you are not sure, send us your symptoms and any test results. We will tell you plainly whether a repair or a replacement makes more sense.
Vehicles That Use the Caterpillar C7
Trucks
- Freightliner Business Class M2 and earlier FL series
- Peterbilt 330, 335 and 340
- Kenworth T300 and related medium models
- Sterling Acterra
- Chevrolet Kodiak and GMC TopKick C6500, C7500 and C8500
- Ford F-650 and F-750
Buses and motorhomes
- School buses from Blue Bird, Thomas and others
- Shuttle and transit buses
- Diesel pusher motorhomes from many of the big RV builders
Equipment and other uses
- Fire trucks and emergency vehicles
- Some Caterpillar machines and industrial power units
- Marine versions in work boats and yachts
A truck engine, a bus engine and an RV engine can carry different ratings, sumps, front ends and wiring. Give us the vehicle and the engine serial number and we will offer the Caterpillar C7 engine for sale that bolts in properly.
7 Proven Checks Before You Buy a Caterpillar C7 Engine for Sale
1. Serial number and arrangement number
These two numbers tell you the build, the rating and the parts list. Any honest seller will send them.
2. A running test
Ask for a video of the engine running, or for test notes. Listen for knocks and watch for smoke and blow by.
3. HEUI system condition
Check for oil leaks around the high pressure oil pump and lines. Ask whether the injectors were tested.
4. Oil and coolant
Look for coolant in the oil and oil in the coolant. Both point to bigger problems.
5. Turbo and aftercooler side
Check turbo shaft play and look for oil in the intake. A failed turbo can send debris into the engine.
6. What is included
ECM, harness, turbo, injectors, high pressure pump, starter, alternator, flywheel. Get the list in writing.
7. Written warranty
Read the terms before you pay. Our approach is explained in our used engine warranty guide.
Common Cat C7 Problems
The C7 has a good reputation, but it has known weak spots. Understanding them helps you choose the right Caterpillar C7 engine for sale and run it longer.
High pressure oil system
HEUI injectors use engine oil at high pressure to fire the injectors. Leaks from the high pressure oil pump, the lines or the injector seals cause hard starting, especially when the engine is hot. The ICP sensor can also fail and give misleading readings.
Injector wear and sticking
Dirty or wrong grade oil can make HEUI injectors stick. You get rough running, misfires and smoke. Good oil and regular changes matter more on this engine than on many others.
Valve cover harness
The injector wiring runs under the valve cover. Over time the harness can chafe or the connectors can loosen, causing misfire codes.
Aftertreatment on 2007 to 2009 engines
Later engines have a diesel particulate filter and a regeneration system. Short trips and idling can clog it.
Cooling problems
A blocked radiator or weak water pump leads to overheating and head gasket trouble, just as on any diesel.
All of these can be checked or fixed. They are simply the things we look at closely before we offer a Caterpillar C7 engine for sale.
How We Test Each Caterpillar C7 Engine for Sale
- We record the serial number, the arrangement number and the rating.
- We run the engine or test compression where possible.
- We check the oil and coolant for contamination.
- We inspect the high pressure oil system for leaks.
- We check the turbo for shaft play and oil.
- We inspect the block and head for cracks and old repairs.
- We photograph the engine from every side and send the photos to you.
- We drain, cap and pack the engine for safe transport.
You see the actual engine before you pay. If anything about the Caterpillar C7 engine for sale is not clear, ask and we will check again.
Notes for RV and Motorhome Owners
A lot of diesel pusher coaches from the mid 2000s left the factory with a C7, often rated around 330 to 360 hp. Owners love the coaches and do not want to replace them, so a Caterpillar C7 engine for sale is a common search among RV owners.
RV engines often sit for long periods and then work hard on long climbs. That combination is tough on injectors, seals and cooling systems. When you replace the engine, it is worth also checking the rear radiator, the charge air cooler, the fan drive and the transmission cooler, because they all live in the same tight engine bay at the back of the coach.
RV ratings and sumps can differ from truck engines. Send us the coach make, model, year and the engine serial number, and we will match the engine to the coach.
Notes for School Bus and Transit Fleets
Bus engines live a hard life of stop and start driving, long idling in cold weather and short daily routes. That is why the high pressure oil system and the particulate filter on later engines get so much wear.
Fleet managers often ask for several engines at once to keep a group of buses running. We can quote multiple units and plan shipping together to save cost. Tell us how many vehicles you run and which serial prefixes they carry, and we will put together a plan for each Caterpillar C7 engine for sale you need.
C7 vs 3126 and C7.1
The 3126 is the older engine of the same size. Many parts look similar, but the electronics, injectors and ratings differ. A 3126 will not simply plug into a truck wired for a C7.
The C7.1 is the later industrial and marine engine with common rail fuel injection and different emissions equipment. It is not a direct swap for an on highway C7 either.
The simplest route is nearly always the same engine your vehicle left the factory with. That is why we stock the Caterpillar C7 engine for sale rather than pushing owners into a costly conversion.
If you run larger trucks, see our Caterpillar C13 engine for sale guide and our Caterpillar 3406E page. The C13 and 3406E are also listed in our shop.
A Word on Marine and Industrial C7 Engines
We also get asked about C7 engines for boats, generators and machines. These share the basic block and head with the truck engine, but they are very different on the outside. Marine engines carry heat exchangers, raw water pumps and marine gear housings. Industrial units have their own sumps, fan drives and power take offs, and their ratings are set for long hours at steady speed.
A truck engine will not drop into a boat, and a marine engine will not drop into a truck without a lot of work. If you need a C7 for one of these uses, tell us the application, the serial number and the arrangement number, and we will look for a Caterpillar C7 engine for sale built for that job rather than one that needs converting.
Replacing a C7 With Another Engine
Some owners ask about fitting a Cummins instead. It can be done, but it usually means a new ECM, wiring, mounts, cooling changes and transmission programming. For most people it costs far more than a good Caterpillar C7 engine for sale. If your truck already has a Cummins, our Cummins ISL engine for sale page is the one to read.
Used, Rebuilt or Remanufactured?
Fairly used. Taken from running vehicles, tested and sold in good condition. The lowest cost and the fastest fix.
Rebuilt. Stripped, cleaned and fitted with new pistons, rings, liners, bearings and gaskets. A longer life for more money.
Remanufactured. Built to a set factory standard with all wear parts replaced. Usually the most expensive. Our guide to remanufactured vs rebuilt engines explains the difference in plain words.
For a bus or truck with years left in it, a clean used Caterpillar C7 engine for sale gives the best value for money.
What a Caterpillar C7 Engine for Sale Costs
We quote each engine separately because the price depends on:
- Complete engine or long block
- Whether the ECM, injectors, high pressure pump and turbo are included
- Rating and serial prefix
- Condition and miles
- Delivery destination and freight method
Tell us what you need and we will price the right Caterpillar C7 engine for sale for you. For a wider look at engine pricing, see our replacement engine cost guide.
Worldwide Shipping
We ship engines by sea and air to buyers in Africa, the Middle East, Asia, Australia and New Zealand, Europe, the Caribbean and the Americas. Each Caterpillar C7 engine for sale is drained, capped, strapped down and packed on a pallet or in a crate.
You get tracking and the export documents. Our shipping policy explains the details, and we are happy to talk you through customs paperwork for your country.
Installation Advice
- Find the cause of the original failure first and fix it.
- Clean or replace the radiator and the charge air cooler.
- Fill with clean oil of the grade Cat specifies. HEUI engines depend on it.
- Prime the fuel system and check the high pressure oil system for leaks before the first start.
- Make sure the ECM software and rating match the vehicle. Your Cat dealer or a good diesel shop can program it.
- Check the transmission settings if the new engine has a different rating.
Follow these steps and your Caterpillar C7 engine for sale should give you many years of service.
Long Block or Complete Engine?
A long block has the block, crank, pistons, rods, head and valve train. It suits you if your injectors, pump, turbo and ECM are healthy.
A complete engine adds the turbo, the HEUI system, the injectors, the water pump and the ancillaries, and sometimes the ECM. It is quicker to fit and is what most fleets want.
Every quote for a Caterpillar C7 engine for sale states which one you are buying, so you can compare fairly.
Keeping Your C7 Healthy
- Change oil and filters on time with the correct grade.
- Keep fuel clean and change fuel filters regularly.
- Keep the cooling system clean and use the right coolant.
- Avoid long idling, especially on 2007 and later engines with a particulate filter.
- Fix small oil leaks around the HEUI system early.
- Replace air filters on schedule.
Owners who do this rarely need to look for another Caterpillar C7 engine for sale.
When Your Engine Arrives
- Photograph the pallet or crate before opening it.
- Check the serial number against your quote.
- Confirm every listed part is present: turbo, injectors, high pressure pump, ECM if included.
- Turn the crank by hand to make sure it moves freely.
- Check that intake, exhaust and oil openings are capped and clean.
- Contact us within the time on your quote if anything does not match.
Because we photograph every Caterpillar C7 engine for sale before it leaves, any question can be settled quickly.
Who Buys C7 Engines From Us
Owner operators with a single medium truck. Fleets with a yard full of M2s and Peterbilts. School bus contractors. Fire departments with older apparatus. RV owners. Diesel shops that repair all of the above and need a supplier they can trust. Importers who sell used Cat engines in their home market.
Whoever you are, you get the same service: honest condition, real photos, the right engine for your serial number and a fair price on every Caterpillar C7 engine for sale.
How to Order Your Caterpillar C7 Engine for Sale
- Send your details. Serial number, arrangement number, vehicle make, model and year. Use the contact page or call +1 (209) 733-0882.
- Receive photos and a written quote including shipping.
- Pay by bank transfer, our only payment method. Read our billing terms.
- We pack and ship with tracking.
- Install with support. We answer questions during fitting.
For tips on buying safely from a distance, read how to buy a used engine online.
Other Engines We Supply
We also stock the Isuzu 6HK1, the Hino J08C, the Cummins ISX15 and the Detroit Series 60. See all our used diesel truck engines or browse the shop.
Why Buy From NJ Global Auto Parts
We check the fit before you pay, send real photos and describe condition honestly. Every Caterpillar C7 engine for sale ships with a written quote, tracking and a written warranty. Read our refund and returns policy and learn more about us.
Frequently Asked Questions
How big is the Cat C7?
It is a 7.2 litre (442 cubic inch) inline six diesel.
What years was the C7 used in trucks?
From about 2003 to the end of the 2009 model year.
Is the C7 a common rail engine?
Most on highway C7 engines use HEUI injection, not common rail. The later C7.1 uses common rail.
Does your Caterpillar C7 engine for sale include the ECM?
Some do and some do not. Your quote will say.
Will a C7 from an RV fit my truck?
Often the core is the same, but ratings, sumps and front ends differ. Send your serial number and we will match it.
Do you ship worldwide?
Yes, every Caterpillar C7 engine for sale can go by sea or air with tracking.
How do I pay?
Bank transfer only. Details come with your quote.
Get Back on the Road
A good chassis deserves a good engine. If you need a tested Caterpillar C7 engine for sale that matches your serial number, with real photos and honest notes, contact us today. We will check the fit, send pictures and give you a clear price, wherever you are.