2007.5-2009 Dodge 6.7L Cummins Engine Parts

The engine in the 2007.5-2009 Ram 6.7L Cummins

The 6.7L arrived in the middle of the 2007 model year and replaced the 5.9L common-rail in the Ram 2500 and 3500, which still wore Dodge badges in these years. It is a grey cast-iron inline-six with a cast-iron head, an induction-hardened forged crank, powdered-metal rods and cast aluminum pistons, and it weighs about 1,120 lb dry. A 4.21 in bore and 4.88 in stroke put peak torque at 1,500 rpm. Pickups are rated 350 hp and 650 lb-ft with the 68RFE automatic, or 350 hp and 610 lb-ft with the G56 manual. The 3500 chassis cab is rated 305 hp and 610 lb-ft. The valvetrain is cam-in-block OHV with four valves per cylinder and solid roller lifters. Compared with the outgoing 5.9L, the 6.7L added displacement, a variable-geometry turbo and full aftertreatment, and the trade was more heat and more emissions-system upkeep.

What fails and why

Head gaskets lead the list. The 6.7L fails them at a higher rate than the 5.9L because it runs higher cylinder pressure to make its torque, and the risk climbs sharply once boost is added. Watch for coolant pushed into the overflow bottle, bubbles in the degas tank under load, coolant loss you cannot trace, white steam from the exhaust, or overheating while towing. Stock trucks mostly see it at high mileage or after repeated overheating.

Oil dilution is the DPF-era problem. Active regeneration uses post-injection, and some of that fuel ends up in the crankcase. Ram's own diesel supplement lists up to 5% fuel dilution as acceptable and recommends diagnosis above that. The signs are an oil level climbing past the full mark, thin oil with a diesel smell, and low viscosity on an oil analysis. Heavy idling, short trips and frequent regens make it worse.

The grid heater is the failure that ends engines. Its stud and nut have been documented coming loose and falling into the intake manifold, and because the engine sits at a 5-degree rake, the hardware rolls back into cylinder #6. Banks documents this for 2007.5-2012 6.7L Rams, and the result can be a complete rebuild. It tracks age and heat cycles more than miles. The turbo deserves a mention too: these were the first Cummins trucks with a variable-geometry turbo, and its parts can coat with soot, oil and ash and stick, which shows up as lag, surging, poor top-end power or an exhaust brake that is weak or stuck on.

Stock replacement vs. upgrade

If the truck is stock and you are chasing a leak or doing a gasket job, genuine Cummins and Mahle gaskets and seals put it back the way it left the factory. When a head gasket has already let go, or more boost is in the plan, the accepted fix is head studs plus a fresh MLS gasket. For oil dilution, the low-cost counter is a 5W-40 full synthetic CJ-4 or CK-4 oil and a shorter interval on the severe schedule. When the block itself is done, a crate short block or long block replaces the core of the engine in one piece.

What we carry

Gaskets, seals and hard parts come from Mahle, Cummins genuine parts, XDP, Dorman, Hamilton Cams and Fleece Performance Engineering: rear main seals, upper gasket kits, oil pumps, timing gear case parts, harmonic balancers, pistons and timing cover hardware. ARP supplies head studs, and D&J Precision Machine supplies remanufactured and Stage 1 cylinder heads, billet valve bridges, and short block, long block and ready-run crate engines. Oil and additives come from Hot Shot's Secret and Lucas Oil, with oil filters from PPE. Belts, tensioners and idler pulleys come from Dayco, Dorman and Cummins, Dorman also covers oil pans and crankcase vent parts, and WCFab builds a billet valve cover. For the rest of the platform, start at our Cummins hub.

Fitment notes

Pickups and 3500 chassis cabs do not always share hard parts, so know which one you have before you order. 2009 was a running-change year: the fuel filter housing, water pump inlet housing and EGR coolant hoses were updated, so check the build date on a 2008 versus a 2009. On any 2007.5-2008 truck, make sure the support bracket from NHTSA recall 08V641000 is in place; it keeps the engine-mounted silencer pad from sagging onto the EGR cooler and starting a fire. Many parts here are listed for wide ranges such as 2003-2018 or 2007.5-2024, so read the years in each title and verify by VIN when in doubt. The 4500 and 5500 chassis cabs ride on a different chassis, and most pickup parts do not interchange.

Frequently asked questions

What oil does the 2007.5-2009 6.7L Cummins take?

Low-ash API CJ-4 or CK-4 oil: 15W-40 above 0 F, or 5W-40 full synthetic for cold weather or year-round use. Capacity is 12.0 quarts with the filter, and the normal interval is 7,500 miles or six months. Low ash matters because the DPF cannot tolerate high-ash oil.

Why is the oil level on my 6.7L going up?

Usually fuel. Post-injection during DPF regeneration can wash diesel into the crankcase, and heavy idling and short trips make it worse. Ram treats up to 5% dilution as acceptable. On heavily idled or towing trucks, Diesel Hub suggests an oil analysis 500-1,000 miles ahead of a scheduled change and keeping idle under 10 minutes in any hour.

Do I need head studs on a stock 6.7L?

Not by default. Stock trucks mostly see head gasket trouble at high mileage or after repeated overheating. Once a gasket has failed, or if you plan to raise boost, head studs and a fresh MLS gasket are the accepted repair, because this engine already runs higher cylinder pressure than the 5.9L.

What is the grid heater bolt problem?

The intake grid heater's stud and nut can loosen and drop into the intake manifold. The engine's 5-degree rake rolls the hardware back into cylinder #6, and Banks documents catastrophic failures that needed a complete rebuild. It is tied to age and heat cycles, so higher-mileage trucks are the most exposed.

When should the valve lash be checked?

The maintenance schedule calls for a lash check and adjustment at 150,000 miles. Spec is 0.010 in intake and 0.026 in exhaust. The valve cover comes off for the job, so have a new valve cover gasket on hand.

Not sure what fits? Call the shop at the number in the header, or use the fitment checker on any product page. We install everything we sell.