The ISL is the engine that quietly moves a lot of the world: city buses, fire engines, refuse trucks, medium haul trucks and big diesel pusher motorhomes. It is strong, it is common, and parts are everywhere. When one wears out, the smart move is usually another ISL. We have a Cummins ISL engine for sale, tested and photographed, and we ship it to buyers all over the world.
Need a price today? Send your engine serial number and CPL number through our contact page or call +1 (209) 733-0882. You can also browse our Cummins engines in the shop. You can also go straight to the Cummins ISL Engine for Sale product page to see the price.
We sell engines and nothing else. The Cummins ISL engine for sale is a steady request from bus operators, fleet owners, fire departments, RV owners and workshops on every continent.
This page covers the specs, the different generations, what the CPL number means, the vehicles that use it, the common problems, how we test and how to order.
The Cummins ISL in Plain Words
Cummins launched the ISL in the late 1990s as an electronic 8.9 litre straight six. It sits between the smaller ISB and ISC engines and the big heavy duty engines such as the ISX. The industrial and marine version is called the QSL9, and there is a natural gas version called the ISL G.
Over the years the engine was updated many times to meet new emissions rules. Early engines used the CAPS fuel system. Later engines moved to high pressure common rail, then added cooled EGR, then a particulate filter, and finally SCR with DEF on the ISL9 from 2010. Each step changed the parts on the outside, but the core of the engine stayed tough.
That long run of production is why a Cummins ISL engine for sale is so easy to match to almost any truck or bus built with one, as long as you know which generation you have.
Cummins ISL Engine Specifications
Figures vary with the year, the rating and the application. We always confirm the serial number and CPL before we quote a Cummins ISL engine for sale.
| Engine type | Inline 6 cylinder, four stroke turbo diesel |
| Displacement | 8.9 litres (540 cubic inches) |
| Bore x stroke | 114 mm x 144.5 mm (4.49 in x 5.69 in) |
| Fuel system | CAPS on early engines, high pressure common rail on later engines |
| Aspiration | Turbocharged, charge air cooled (variable geometry turbo on many later engines) |
| Horsepower | About 250 to 400 hp on common ratings |
| Peak torque | Up to about 1,250 lb-ft depending on rating |
| Compression ratio | About 16.6:1 |
| Dry weight | About 1,550 lb (around 700 kg) |
| Oil capacity | About 29 US quarts |
| Engine controllers | CM550, CM850, CM2150 and CM2250 depending on year |
ISL Generations and ECM Types
Knowing the generation is the most important step in finding the right Cummins ISL engine for sale.
- Early ISL (late 1990s to early 2000s). CAPS fuel system, CM550 controller. Simple emissions equipment.
- EPA 2004 ISL (CM850). Cooled EGR and a variable geometry turbo arrive on many engines.
- EPA 2007 ISL (CM2150). A diesel particulate filter is added, plus updated electronics.
- ISL9 from 2010 (CM2250). SCR and DEF join the EGR and DPF. Higher ratings and better economy.
- ISL G. The natural gas version for buses and refuse trucks.
- QSL9. The industrial and marine version for machines, generators and boats.
You cannot freely swap an engine from one generation into a vehicle built for another. The wiring, the controller, the aftertreatment and the transmission programming all expect a particular engine.
What Is a CPL Number?
CPL stands for Critical Parts List. It is a four digit number on the engine data plate, and it tells Cummins and any good parts supplier exactly how the engine was built: pistons, injectors, turbo, fuel system and rating.
Two ISL engines with different CPL numbers can need different parts to work in the same vehicle. That is why we always ask for the CPL along with the serial number. With both, we can match a Cummins ISL engine for sale that drops in with the least work.
The data plate is usually on the front gear cover or the rocker cover. Send a clear photo and we will do the rest. If the plate is missing or painted over, the serial number is also stamped on the block, and our team can often work out the build from that and from photos of the fuel system and turbo.
Trucks, Buses and RVs With the Cummins ISL
Trucks
- Freightliner Business Class M2 106 and 112
- Kenworth and Peterbilt medium and regional trucks (some sold as the PACCAR PX-9, which is based on the ISL9)
- International medium trucks with the ISL9 in later years
- Refuse trucks, concrete mixers and vocational trucks
Buses and coaches
- Transit buses from Gillig, New Flyer and others
- Motorcoaches and shuttle buses
- Some school buses
Fire and emergency
- Fire engines and rescue trucks from many builders
Motorhomes
- Diesel pusher coaches from the major RV builders, often rated 350 to 400 hp
Each application can have a different sump, front end, fan drive and rating. Send your vehicle details and we will match the right Cummins ISL engine for sale.
7 Proven Checks Before You Buy a Cummins ISL Engine for Sale
1. Serial number and CPL
Without them you are guessing. Any decent seller will send a photo of the data plate.
2. Running test or test results
A running video or test notes show how the engine starts, idles and sounds.
3. Blow by and smoke
Heavy blow by or blue smoke points to worn rings and liners.
4. Oil and coolant
Coolant in the oil can come from an EGR cooler, an oil cooler, a head gasket or a cracked head. Find out which.
5. Turbo and VGT actuator
Check the turbo for play and ask whether the VGT actuator works on later engines.
6. What comes with it
ECM, harness, turbo, injectors, fuel pump, EGR parts, starter and alternator. Get the list in writing.
7. Written warranty
Read the terms before you pay. Our used engine warranty guide explains how ours works.
Common Cummins ISL Problems
Every engine family has weak spots. These are the ones we look for before we offer a Cummins ISL engine for sale.
CAPS fuel pump on early engines
The CAPS pump on early ISL engines is known for wear and leaks. Many have been rebuilt or replaced over the years.
EGR valve and EGR cooler
On 2004 and later engines the EGR valve can stick with soot and the EGR cooler can crack and leak coolant. Watch for coolant loss and white smoke.
VGT turbo actuator
The variable geometry turbo can stick or its actuator can fail, causing low power and fault codes.
DPF and aftertreatment
On 2007 and later engines, buses and short haul trucks that idle a lot can clog the diesel particulate filter. ISL9 engines also depend on a healthy SCR and DEF system.
Injectors and fuel quality
Common rail injectors need clean fuel. Water and dirt wear them quickly.
Oil and coolant leaks
Front crank seals, oil cooler gaskets and coolant hoses are common leak points on high mile engines.
None of these faults make the ISL a poor choice. They just show why it pays to buy from a seller who checks.
How We Test Each Cummins ISL Engine for Sale
- We record the serial number, CPL and rating.
- We run the engine or test it where possible.
- We check oil and coolant for contamination.
- We inspect the turbo, the VGT actuator and the EGR parts.
- We check the fuel system for leaks.
- We look over the block and head for cracks and repairs.
- We photograph the engine from all sides and send the photos to you.
- We drain, cap and pack the engine for transport.
You see the actual engine before you pay. If you want another photo or more information about a Cummins ISL engine for sale, just ask.
A Note on the ISL G Natural Gas Engine
Many city buses and refuse trucks run the ISL G, the natural gas version. It shares the 8.9 litre size and a lot of the base engine, but it uses spark ignition, a different head, different pistons and a completely different fuel system.
A diesel ISL will not go into a gas vehicle without a full conversion, and the reverse is just as hard. If your fleet runs on gas, tell us so when you ask for a quote. We will look for a gas engine, or a Cummins ISL engine for sale built to the right specification, rather than send you something that needs months of work.
Parts Supply for the ISL
One of the best things about this engine is how easy it is to keep alive. Cummins has a dealer and parts network in most countries, and there is a large aftermarket for ISL parts: overhaul kits, cylinder heads, turbos, injectors, EGR parts, water pumps and gasket sets. Many local diesel shops already know the engine well. That means a Cummins ISL engine for sale is a low risk buy even in places far from the original market. If you need parts along with your engine, ask when you request your quote.
ISL vs ISC, ISB and ISX
The ISC is the 8.3 litre engine with a similar layout. It shares a lot with the ISL, but the displacement, the internal parts and many ratings differ. The ISB is the smaller 5.9 or 6.7 litre engine, and the ISX is the big 15 litre heavy duty engine.
Each fits a different class of vehicle, so the easiest fix is to replace like with like. If you run bigger trucks, see our Cummins ISX15 engine for sale guide or the ISX15 in our shop. For older heavy trucks, our Cummins N14 page may help, and for industrial QSB users there is our Cummins QSB guide.
Signs Your ISL Needs Replacing
A lot of ISL faults are repairs: an EGR valve, a turbo actuator, a set of injectors. But some signs say a Cummins ISL engine for sale is the better spend.
- Bottom end knock from a bearing failure.
- Heavy blow by and oil use from worn rings and liners.
- Coolant in the oil that returns after the EGR cooler and oil cooler have been checked, pointing to a cracked head or block.
- Low compression across several cylinders.
- Damage after a dropped valve or turbo failure that sent debris into the cylinders.
Send us the symptoms and any shop reports. We will give you an honest answer on repair or replace.
Used, Rebuilt or Remanufactured?
Fairly used engines come from running vehicles, are tested and are sold in good condition. They are the cheapest and fastest option.
Rebuilt engines are taken apart and fitted with new pistons, rings, liners, bearings and gaskets. They cost more but give a fresh start.
Remanufactured engines are built to a set standard with all wear parts replaced, and they cost the most. Our guide to remanufactured vs rebuilt engines explains the choice.
For buses and trucks with life left in the chassis, a clean used Cummins ISL engine for sale usually gives the best return on the money.
Long Block or Complete Engine?
A long block is the block, crank, pistons, liners, rods, head, camshaft and valve train. It suits you if your fuel system, turbo, EGR parts and ECM are healthy.
A complete engine includes the turbo, fuel pump, injectors, rail, EGR parts, water pump and usually the starter and alternator. Some come with the ECM and harness. It is quicker to fit and is what most fleets choose.
Each quote for a Cummins ISL engine for sale states which one you are buying, so prices can be compared fairly.
What a Cummins ISL Engine for Sale Costs
We price each engine on its own. The main things that change the price are:
- Generation and ECM type
- Complete engine or long block
- Included parts such as ECM, turbo and injectors
- Miles and condition
- Shipping method and destination
Tell us your serial and CPL numbers and we will price the matching Cummins ISL engine for sale. Our guide to replacement engine cost explains more.
Notes for Bus and Fleet Operators
Transit buses and refuse trucks are some of the hardest jobs any engine can have. Constant stop and start, long idling, heavy loads and high heat. That is hard on the EGR system, the turbo, the DPF and the cooling system.
If you run a fleet, we can quote several engines at once and plan shipping together to cut cost. Tell us how many vehicles you run and which generations they use, and we will put together a plan for each Cummins ISL engine for sale you need.
Notes for RV Owners
RV owners are some of our most careful buyers of a Cummins ISL engine for sale. Diesel pusher coaches with the ISL are often worth far more than the cost of a replacement engine. RV engines can sit for months and then climb mountain passes at full load, which is hard on injectors, seals and cooling parts.
When you replace an RV engine, check the rear radiator, the charge air cooler, the fan drive and the transmission cooler at the same time. Send us the coach make, model, year, serial number and CPL, and we will find the right Cummins ISL engine for sale for your coach.
Worldwide Shipping
We ship to buyers across Africa, the Middle East, Asia, Australia and the Pacific, Europe, the Caribbean, and North, Central and South America. Sea freight is the cheaper choice for most buyers. Air freight is faster when a bus or truck is off the road and losing money.
Each Cummins ISL engine for sale is drained, capped, strapped down and packed on a pallet or in a crate, and sent with tracking and export documents. Read our shipping policy for more.
Installation Advice
- Fix the cause of the old engine failure before you fit the new one.
- Clean or replace the radiator and the charge air cooler.
- Check the EGR cooler and the aftertreatment if the old engine had coolant or soot problems.
- Fit new fuel filters and prime the system.
- Fill with the oil grade Cummins specifies for your emissions level.
- Make sure the ECM calibration matches the vehicle and the transmission.
- Check hoses, clamps and belts. Old rubber often fails on a fresh engine.
Do this and your Cummins ISL engine for sale will give you years of reliable work.
Keeping Your ISL Healthy
A few plain habits keep a Cummins ISL engine for sale from our stock running for years after it goes in.
- Change oil and filters on time with the right oil grade.
- Keep fuel clean and drain water separators.
- Do not let engines idle for hours.
- Let the DPF finish its regeneration.
- Use quality DEF on ISL9 engines and keep the tank clean.
- Fix coolant leaks early, especially around the EGR cooler.
When the Engine Arrives
- Photograph the pallet or crate before you open it.
- Match the serial number to your quote.
- Check that every listed part is there.
- Turn the engine by hand to check it moves freely.
- Check all openings are capped and clean.
- Contact us within the time on your quote if anything is wrong.
We photograph each Cummins ISL engine for sale before shipping, so any question is quickly settled.
Who Buys the ISL From Us
Transit operators keeping older buses in service. Refuse and vocational fleets. Fire departments with trusted apparatus. Owner operators with Freightliner M2 or similar trucks. RV owners who love their coach. Diesel workshops that need a steady supply. Engine importers who resell in their home markets.
Every one of them gets the same thing from us: the right engine for the serial and CPL numbers, honest condition notes, real photos and a fair price on each Cummins ISL engine for sale. Whether you need one engine or a container, the process is the same. We keep you informed from the first message until the engine is on your floor, and every Cummins ISL engine for sale we ship is tracked the whole way. If you have a question at any point, you talk to people who know engines, not a call centre reading from a script.
How to Order Your Cummins ISL Engine for Sale
- Send your details. Serial number, CPL, vehicle make, model and year through the contact page, or call +1 (209) 733-0882.
- Get photos and a written quote including shipping.
- Pay by bank transfer. It is the only payment method we accept. See our billing terms.
- We ship with tracking.
- You fit the engine and we stay on hand for questions.
Want more buying tips? Read how to buy a used engine online and our notes on low mileage used engines.
More Engines We Sell
We also supply the Caterpillar C7 engine for sale, the Isuzu 6HK1, the Hino J05E, the Detroit DD15 and the Volvo D13. See all our used diesel truck engines or visit the shop.
Why Buy From NJ Global Auto Parts
We confirm the fit before you pay, send real photos and describe condition honestly. Every Cummins ISL 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 Cummins ISL?
It is an 8.9 litre (540 cubic inch) inline six diesel.
What is the difference between the ISL and the ISL9?
The ISL9 is the 2010 and later version with SCR and DEF, a newer controller and updated parts.
Is the ISL common rail?
Later engines are. Early engines used the CAPS fuel system.
Does your Cummins ISL engine for sale include the ECM?
Some do and some do not. Your quote will say.
Can an ISC go in place of an ISL?
They are related, but not the same. It is best to replace like with like.
Do you ship worldwide?
Yes, every Cummins ISL engine for sale can go by sea or air with tracking.
How do I pay?
Bank transfer only. Details come with your quote.
Get Your Fleet Moving Again
A bus, truck or coach that is off the road costs money every day. If you need a tested Cummins ISL engine for sale that matches your serial and CPL numbers, with real photos and honest notes, contact us today. We will confirm the fit, send pictures and give you a clear price, wherever you are.