Caterpillar 7.2L L6 Diesel (Review, Horsepower, Oil Capacity)
Good diesel engines are found everywhere. Cummins is not the only diesel engine maker out there. Caterpillar is a fine company as are many other diesel makers. They produce top engines like the C7 to make sure you can have a reliable engine that gets you to where you want to be every time.
Caterpillar comes with a top reputation. It has been making big construction equipment with powerful motors for generations. The HP on the C& has 8 different settings and is rated to produce between 210 to 360, with torque ranging between 525 to 925 lb-ft.
To learn more about this motor, just continue to read our article. It provides the technical information you want to know about before you make a final engine buying decision. Take a few minutes to see how this information can help you.
A Little C7 History
This was supposed to be the ‘gold child’ of all diesel engines. The concept was to mix raw horsepower with computer controlling technology. It was also designed to meet the new 2004 EPA emission standards.
Caterpillar released the engine in 2003, one month before the Tier 4 regulations were going to be implemented. The purpose behind this motor was to replace the popular 3126 diesel that many truck owners preferred.
Originally, the C7 was to be installed in class 8 trucks that weight under 35,000 pounds. What made the C7 different from the 3126 was “the HEUI injector. The HEUI injector allows for multiple injections at different metered rates”. Other than that and a few other changes, the two motors were fairly similar to each other.
However, this motor did not enjoy a long production run. It started in 2003 and ended in 2009
Caterpillar 7.2 Diesel Engine
This was an inline 6-cylinder motor that came with a 7.2-liter displacement. Plus it came with a dry weight of 1425 pounds and carried two oil capacity limits. One limit stopped at 4.75 gallons while the second limit reached 6.75 gallons. The latter had a deeper sump pump and oil pan.
With the then current technology, Caterpillar produced this motor in 8 different horsepower ratings. Those ratings went from 210 to 360 and the torque capability ranged between 525 and 925 lb-ft.
What Caterpillar did though was restrict the 330 and the 360 HO options to RVs and firefighting vehicles. The reason Caterpillar did not continue this engine’s production was that the company did not think that the cost was worth it. In 2010 they left the over-the-road market to Cummins and Paccar and focused on building off-road engines for heavy construction equipment.
While it lasted, this was a good engine with a few minor problems. One of those problems was you could only drive for half a million miles before needing an overhaul.
The C-7 L6 Specs
| Engine category | The data |
| Minimum power | 225 HP & 520 lb-ft |
| Maximum power | 300 HP & 925 lb-ft |
| RPMS | 1800 to 2200 |
| Emissions rating | U.S. EPA Tier 3 Equivalent, China Stage II, EU Stage IIIA Equivalent |
| Engine Configuration | Inline 6, 4-Stroke-Cycle Diesel |
| Bore | 4.33 |
| Stroke | 5.0 inches |
| Compression | 16.2:1 |
| Combustion system | Direct injection |
| Computer system | ADEM A4 Electronic Control Unit |
| Dry weight | 1296 pounds |
| Dimensions | 40.6 H x 41.5 L x 29.8 W (all in inches) |
**data retrieved from https://www.capitalremanexchange.com/cat-c7-specs-and-engine-history/
The motor also came in different torque configurations. There was both a high and a low torque model. This flexibility allowed different truck manufacturers to use the transmission they preferred. That transmission torque capacity had to be matched to the C7 model the different companies used.
It can be said that the strict EPA restrictions were the death of many a good engine. It is what drove caterpillar from continuing to dominate the over-the-road diesel engine market.
Our 7.2l l6 Diesel Engine Review
To us, a 500,000-mile lifetime before needing an overhaul sounds pretty good. But in the diesel engine industry, it was not a very good lifespan as some diesel engines from other brands made it to 1,000,000.
There are flaws to this motor but those flaws were easily overcome. Part of the designs that helped overcome any flaws was the hydraulically activated electronic control injector (HEUI) and the Advanced Combustion Emissions Reduction Technology (ACERT).
Both of these systems were made to cut diesel emissions. The3126 had early versions of both installed and the Cat C7 just improved on them. The cost of the improvement was too much for Caterpillar and a good engine was stopped.
The power of the motor was there but the ACERT system seemed to fail as it needed continuous regeneration which created low fuel mileage and low power.
Overheating was another issue that Caterpillar could not solve. The C7 was supposed to turn the fan on at 235 degrees F but many owners reported overheating at 200 degrees F.
This engine was plagued by many minor problems. For example, clogged filters and the turbocharger inlet was always getting clogged. These problems also contributed to the low performance of the motor.
Caterpillar just could not keep up with the emission restrictions and their technology could not produce top systems that met the emissions demand. It just became too expensive to maintain the engine and Caterpillar pulled the plug.
This motor was a good try but it just could not meet expectations. Driving at 1100 RPM uphill to avoid overheating was not a good solution.
7.2L L6 Diesel Horsepower
There were two versions of this motor produced. One was the EPA 04 and the other was the EPA 07. They are named this because 04 was the first year of new EPA regulations taking effect and 07 was the next change in EPA emission regulations.
The horsepower produced by the 04 was between 190 to 230 at 2500 RPM. Those figures were raised to 230 to 330 at 2400 RPM. You got the second set of HP when the engine was installed in a fire truck or an RV.
For the 07 models, the HP was 210 at 250 RPM and 300 at 2400 RPM. Then it was 300 to 360 HP at 2400 RPM when installed in fire trucks and RVs. The amount of toque was different between the 04 and 07 engines.
The 04 produced between 520 and 860 lb-ft of torque while the 07 went to 520 to 925 lb-ft. Both models were rated at 1440 RPM.
CAT 7.2 L6 Oil Capacity
This engine came with two different oil capacities. One version only allowed for 4.75 gallons of oil while another version was equipped with an oil tank that held 6.7 gallons of oil.
The cooling system for both versions seems to be a hair under 4 gallons. The reservoir held 3.99 gallons of coolant. The emissions rating for the C7 was Tier 3 and Caterpillar found it expensive and difficult to continue to meet the new regulations the EPA kept putting out.
This situation pushed Caterpillar to move out of the on-road engine market and focus more on the off-road engine market. The company still makes a great diesel engine, you just can’t use it on the road.
However, the C7 is not a long-living motor and that was one of its problems. You would have to overhaul it sooner than you wanted to. But the good point is that it lasted 150,000 miles longer than a Cummins diesel model did.
Finding a Caterpillar 7.2 Diesel Engine For Sale
If you go to the link we placed under the table above, you will find at the end of their article their great offer. They will re-manufacture the C7 for you on a new core. You just have to give them your old core in exchange.
You have to read the rest of the article to get all that they will do for you concerning this engine. There are other similar businesses that have this engine for sale. One charges at least $7500 for the ones they have in stock.
A quick search using the words ‘Caterpillar 7.2 diesel engine for sale” turns up a good number of businesses that sell this motor. Or you can check the usual sources like eBay, junk yards, used parts stores, etc., to find a good engine at a reasonable price.
One thing you should keep in mind is that the 3126 was also a 7.2 Liter engine and they were grandfathered into the new 04 and 007 EPA regulations.
Some Final Words
It is a good diesel motor but probably not the best. The EPA had more to do with its demise than any mechanical failure or part did. If you want a motor that lasts 500,000 miles, then this is the one to buy.
The Cummins 5.9 only lasts 350,000 miles before needing an overhaul. With the right repair work, you should have an engine that outlasts your RV.
