Data report

6.7 Cummins Problems: What Actually Breaks on 2007.5-2018 Ram Diesels

Published September 23, 2026 · Updated October 10, 2026 · 17 min read

The 6.7 Cummins has a reputation as the engine that outlives the truck, and the long block mostly earns it. What fails is the equipment bolted around it: the exhaust filter, the turbo's electric actuator, the DEF system and one small bolt in the intake that can wreck the engine. One 2017 Ram 2500 owner told NHTSA the grid heater bolt fell into cylinder 6 at 73,554 miles.

Which of these you face depends mostly on the model year. This guide sorts them by year with 656 NHTSA owner complaints that clearly involve the diesel, Ram's recalls and service bulletins, and current part prices, and it says where that evidence is thin.

The one idea: the model year decides the equipment

Every 6.7 Cummins in a 2007.5-2018 Ram has a diesel particulate filter (DPF) and exhaust gas recirculation (EGR). From the 2013 model year Ram added a DEF/SCR system, with a tank of diesel exhaust fluid, a pump, a dosing injector and NOx sensors, and switched the pickups from the Holset HE351VE turbo to the HE300VG. aggregated

So a 2010 truck and a 2015 truck share an engine but not a list of problems. A 2007.5-2012 truck cannot have a DEF problem, and it regenerates its filter more often because it has no SCR system to do part of the cleaning. A 2013-2018 truck regenerates less, but it adds the DEF system and the actuator that owners of these years complain about most. aggregated

What owners report to NHTSA

Four problems make up most of the engine complaints: DPF clogging (56), the turbo actuator and exhaust brake (54), the DEF system (53) and the grid heater (20). Together they account for 183 of the 234 complaints that name a specific engine problem.

The water pump count (16) is only the complaints that clearly involve the diesel; Ram's recall on 2013-2017 diesel water pumps is covered below. Head gasket failures, which some buyer's guides list among the common 6.7 problems, do not appear in a single diesel complaint we found.

A note on how we counted: Ram sold the same 2500 and 3500 trucks with gasoline Hemi engines, and NHTSA files both under the same names. We kept only complaints that name the diesel, Cummins, the 6.7 or a diesel-only part, which leaves out some real diesel complaints. Exhaust manifold bolt complaints in the same trucks, for example, are almost all about the Hemi.

6.7 Cummins years to avoid: what changes by year

Short answer: no year of the 2007.5-2018 6.7 is one to avoid outright, but each era has its weak spot. 2007.5-2009 trucks carry most of the DPF complaints (33 of 56). 2013-2018 trucks carry every DEF complaint and 50 of 54 turbo actuator complaints. 2010-2012 trucks have the fewest engine complaints in our data.

Complaints: NHTSA owner complaints filed on 2007-2018 Dodge and Ram 2500, 3500, 4500 and 5500 trucks, pulled 2026-09-12, extra NHTSA model names added 2026-10-10. Raw counts, not adjusted for how many trucks were sold or how old they are. NHTSA returns no complaints for 2011-2012 Ram 3500 pickups under any name we found, so those two years are undercounted. Some 2007 complaints may be about early 2007 trucks with the 5.9 when the engine is not named.

How to read this table. It counts complaints, not failures, and the counts depend on how many trucks were sold and when owners chose to file, which we cannot adjust for. Two patterns are too strong to be only that:

• The DPF problem is an early-truck problem. 26 of the 56 DPF complaints are on 2007 and 2008 trucks, and only 3 are on 2010-2012 trucks. Buyer's guides that name 2010 and 2012 as the worst emissions years do not match this data, though NHTSA's missing 2011-2012 Ram 3500 complaints mean we cannot rule it out for those trucks.
• The turbo actuator is a 2013-2018 problem. 50 of 54 turbo complaints are on these years, and 46 of all 54 were filed in 2019 or later.

The grid heater complaints look like a 2016-2018 problem in the table (17 of 20), but every one of the 20 was filed in 2023 or later. That is when owners started hearing about the failure, not when it started; the design is the same on every 2007.5-2018 truck.

Check this first on any 6.7: the grid heater bolt

"The grid heater bolt failed and fell into the intake runner. The bolt then fell into the number 6 cylinder causing engine failure."

Owner of a 2017 Ram 2500 with 73,554 miles, 2025. NHTSA complaint 11643462

What it is. The 6.7 warms its intake air for cold starts with an electric grid heater in the intake horn, after the turbo and the intercooler. Its power terminal carries high current through a small nut and bolt that sit inside the intake. Heat, vibration and arcing wear that hardware until it breaks off. Once loose, the piece is pulled into the intake manifold and into a cylinder, where it damages the piston, valves and head. aggregated

What owners report. 14 of the 20 grid heater complaints describe a nut or bolt reaching a cylinder or coming close to it, and 7 name cylinder 6. Several owners were towing when it happened. verified

The warning sign: code P2609. Ram told dealers that on 2012-2016 6.7 Cummins engines with intake heater problems or codes P2609 and P0542, they should replace the heater grid and its relay as a set and inspect the cable between them for overheating. verified One 2017 owner got P2609 at 83,015 miles, replaced the relay, and when the code came back found the bolt already broken but "fused to the heater grid plate still" (NHTSA complaint 11516357). If P2609 appears, stop driving the truck hard and have the intake horn opened.

The fix. Aftermarket retention and upgrade kits replace the factory hardware, and list for about $220. One owner who caught it in time reported "the fix was a $1k kit" installed (NHTSA complaint 11518672). Owners whose bolt reached a cylinder reported about $3,000 when the engine could be taken apart and repaired, and $10,000 to $20,000 when the damage was worse.

Is there a recall? Not for the bolt on 2007.5-2018 trucks. Ram's recalls 21V-163 and 23V-060 cover a heater grid relay that can short and start a fire on 2021-2023 trucks, a different part on the newer engine. verified

Exhaust brake not working? The turbo actuator (2013-2018)

"I was towing an approximately 6000lb trailer when the turbo actuator failed. I lost both boost to control power and loss of the exhaust brake."

Owner of a 2017 Ram 2500, 2023. NHTSA complaint 11555148

What to do. On a test drive, switch the exhaust brake on and lift off the throttle at speed: you should feel the truck slow noticeably. Then scan for stored codes.

What you will see. A healthy actuator gives a strong exhaust brake and no turbo codes. A failing one shows up as a weak or missing exhaust brake, a check-engine light, low power and limp mode. Ram's warranty bulletin for 2015 trucks lists the codes: U010C (lost communication with the turbo control module), P003A, P00AF, P0046 and P0234. verified

Why. The variable-geometry turbo is also the exhaust brake and part of how the truck heats the DPF for a regeneration. Its electronic actuator lives next to a hot turbo and fails on its own; soot on the vanes can also make them stick. 34 of the 54 turbo complaints name the actuator and 24 mention the exhaust brake. aggregated

Ram's warranty extensions. Ram extended the warranty on the turbocharger actuator for certain 2015 Ram 2500 and 3500 pickups (bulletin 09-005-22, program X99) and for certain 2013-2015 Ram 4500 and 5500 cab chassis (bulletin 09-001-22, program X93, with an updated actuator), both issued in 2022. If you own one of these, ask a Ram dealer to check your VIN before you pay for an actuator. Several owners of 2016 trucks told NHTSA the same failure was not covered on their year. verified

What it costs. Owners reported paying $1,750 to $3,900 for an actuator replacement between 2019 and 2023, and Ram issued a 2020 service note on telling an actuator failure apart from a turbo failure, so make sure the diagnosis says which. A complete 2013-2018 turbo lists from about $3,300 remanufactured to about $6,000 new.

DPF and regeneration problems (worst on 2007.5-2009)

"The dealer told me that the filters get clogged and I should drive it down the interstate to clean them out."

Owner of a 2007 Ram 3500, 2009. NHTSA complaint 10262688

What to do. Ask how the truck was driven. Scan for soot-load codes and look at the regeneration history if the scan tool shows it. On a test drive, watch the overhead display for "exhaust filter full" or regeneration messages.

What you will see. A truck that works and tows on the highway usually regenerates without anyone noticing. A truck that idled for hours or made short trips can show frequent regenerations, aborted regens, power loss and limp mode. aggregated

Why. The filter catches soot and burns it off at high exhaust temperature. Short trips and idling never get the exhaust hot enough for long enough, so the soot builds up faster than the truck can burn it. Early trucks had no SCR system and regenerated the most. A stuck turbo or a faulty EGR valve or sensor can also stop a regen from finishing. aggregated

What it costs. Owners reported $2,000 to $3,000 for a replacement filter in 2008-2013 complaints, and quotes of $5,000 to $6,000 when the filter was replaced together with the catalyst or the EGR valve. A professional cleaning is the cheaper path if the filter is not cracked. Fix whatever stopped the regenerations first, or the new filter clogs too.

Fuel in the oil. Failed regenerations can leave diesel in the engine oil. On a 6.7, an oil level that rises between changes means fuel (or coolant) in the oil; have it checked. aggregated

DEF and SCR problems (2013-2018)

"Then message came up and said in 200 miles truck will shut down to only 5 mph."

Owner of a 2013 Ram 3500, 2015. NHTSA complaint 10785161

What you will see. A DEF warning, then a countdown in miles to a 5 mph limit if the fault is not fixed. 19 of the 53 DEF complaints mention that 5 mph limit. Owners also describe a DEF gauge that reads empty on a full tank, failed DEF pumps and "contaminated DEF" diagnoses. verified

Why. The system adds a tank, a pump with a heater, a dosing injector and NOx sensors. Failures concentrate in the pump and heater assembly, the sensors and fluid that is old, contaminated or has crystallized in the lines. aggregated

What to do. Use fresh, sealed DEF, and do not ignore a DEF message on a trip: the countdown is real. On a used truck, scan for DEF and NOx codes and ask whether the DEF pump has been replaced.

What it costs. Owners reported $1,700 to $2,900 for DEF system repairs in 2015-2025 complaints, including a DEF pump replaced at an independent shop for $2,866 after a $3,900 dealer quote.

Water pump recall (2013-2017)

Ram recalled 2013-2017 Ram 2500, 3500 and 4500/5500 cab chassis trucks with the 6.7 Cummins whose Concentric-brand water pumps without a vent hole can leak coolant and raise the risk of an engine compartment fire (recall 17V-562, Ram's number T51). Dealers replace the pump free of charge. verified 15 of the 16 diesel water pump complaints are on 2013-2017 trucks, and most of them are about this recall, often from owners still waiting for replacement parts months after the notice.

Check the VIN on any 2013-2017 truck at NHTSA's recall lookup. If the recall is done, the pump is the replacement. On a truck outside the recall, a water pump lists for about $220 to $240.

The other open recalls to check

Run every 6.7 through the VIN lookup, not only the 2013-2017 trucks. These recalls involve the diesel engine bay: verified

• 08V-641, 2007-2008 Ram 2500 and 3500 pickups: a silencer pad can sag onto the EGR cooler and start a fire. Dealers add a support bracket.
• 14V-635, 2010-2014 Ram 2500-5500: the diesel fuel heater's electrical connectors can overheat and the heater can leak fuel. Dealers replace the connector and inspect the heater.
• 15V-592, certain 2016 Ram 2500-5500 built in a two-week window in 2015: the engine control module can short and stall the engine. Dealers replace it.

Fuel supply, EGR and the rest

These show up far less often in the complaints, but they are on every inspection list:

• Lift pump and fuel pressure (14 complaints). Low fuel pressure codes (P0087), long cranks and power loss under load point to the supply side before the high-pressure pump. Change both fuel filters on schedule and drain the water separator; water ruins injectors. A stock-type in-tank lift pump lists for about $370. aggregated
• EGR valve and cooler (13 complaints). A sooted EGR valve sets flow codes and causes rough running; a cracked cooler loses coolant with white, sweet-smelling exhaust. The cooler design changed for 2010, so order by year. List prices are about $1,560 for the valve and $640 (2007.5-2009) or $2,090 (2010-2018) for the cooler. aggregated
• Injectors (4 complaints). Rare in the data. A "chuff" sound at idle can be a leaking injector seal, which is cheaper than an injector. aggregated
• Crankcase breather (CCV) filter. A maintenance item that fails silently; replace it at the interval in your owner's information. aggregated

What the 2007.5-2018 6.7 usually does not do

• Blow head gaskets at stock power. Not one diesel complaint we found names a head gasket. Shop guides tie 6.7 head gasket failures to overheating and to engines run well above stock power. aggregated
• Eat a CP4 fuel pump. These trucks use the Bosch CP3 high-pressure pump. The CP4 failure stories belong to the updated 2019-and-later engine. aggregated

What you found, and what to do about it

Part prices are list prices at the time of publication; the aftermarket is often cheaper. Owner-reported costs come from NHTSA complaints and show what those owners paid in those years, not a quote. We do not have reliable labor estimates for these jobs.

Before you buy a used 6.7 Cummins Ram

• Run the VIN through NHTSA's recall lookup and ask the seller for the recall paperwork.
• Ask about the grid heater. Has the hardware been upgraded? If not, price the kit and the labor into your offer.
• Scan it. Stored and pending codes, with special attention to P2609, P0542, turbo actuator codes, soot-load codes and DEF/NOx codes. Ask for the regeneration history if the tool shows it.
• Drive it with the exhaust brake on, and on a highway long enough to see whether a regeneration message appears.
• Pull the dipstick. A level above full or a fuel smell needs an explanation.
• Ask how it was used. Highway towing is easy on the emissions hardware; idling and short trips are not.
• Look at the transmission too. The 68RFE automatic and the manual gearboxes have their own complaint history, which this engine guide does not cover.

What we cannot tell you

• How often each problem happens. Complaints are not failure rates, and owners report safety scares far more than routine repairs.
• Every diesel complaint. We counted only complaints that clearly involve the diesel, so real diesel complaints that do not name it are left out. NHTSA returns no complaints at all for 2011-2012 Ram 3500 pickups under any name we found.
• Which years are truly best. 2010-2012 trucks draw the fewest engine complaints (10 that name a problem), but we have no sales figures to adjust for, 2011-2012 overlaps the missing 3500 data, and these trucks are now old enough that condition matters more than year.
• How common the grid heater failure is. Every complaint about it was filed from 2023 on, after owners began hearing about it, so the counts reflect awareness as much as failures.
• Labor costs. We quote what owners reported and part list prices, not shop rates.

FAQ

Go deeper

Each of these pages shows the sources behind every claim, the confidence tier and the part numbers:

• Cummins 6.7 (2007.5-2018) platform page · the updated 2019+ 6.7
• The big four: Grid heater bolt · VGT turbo and actuator · DPF clogging · DEF / SCR system
• The rest: Water pump · Lift pump and fuel delivery · EGR valve · EGR cooler · Fuel in the oil · Head gasket
• Parts: Grid heater upgrade kit · VGT actuator · 2013-2018 turbo · DEF pump · Water pump · Lift pump
• How we verify and tag facts

Sources. NHTSA owner complaints database (US government public domain), keyword-matched and limited to complaints that clearly involve the diesel; owner quotes are taken from complaint narratives with capitalization normalized, and complaint numbers are given so you can read them in full. NHTSA recall records 08V-641, 14V-635, 15V-592, 17V-562, 21V-163 and 23V-060. Ram bulletins 09-005-22 and 09-001-22 and Ram's intake heater service note, from NHTSA's manufacturer communications index. Emissions hardware and turbo by model year from the platform record. Part prices are list prices at the time of publication. Torque Index aggregates and cross-checks public information, takes no paid placement and does not provide repair or inspection services.