Fleece Performance Solves The 6.7L Cummins Grid Heater Problem Once And For All

For years, 6.7-liter Cummins owners have lived with a nagging fear lurking inside the intake system: the factory grid heater bolt and nut. What started as isolated failures has become one of the diesel aftermarket’s most talked-about reliability concerns, with countless owners worried about catastrophic engine damage caused by OE grid heater hardware entering the combustion chamber. Now, Fleece Performance Engineering has unveiled what may be the most comprehensive solution yet for 2007.5-2024 Ram HD trucks equipped with the 6.7-liter Cummins.

The new Fleece Performance Intake Horn and Grid Heater Kit doesn’t just eliminate the problematic factory setup—it improves airflow, enhances throttle response, simplifies installation, and even maintains cold-weather drivability for truck owners who depend on their Cummins in freezing conditions. Designed to fit 2500, 3500, 4500, and 5500 models, the kit delivers broad compatibility while preserving a factory-style appearance under the hood.

A Permanent Fix For A Well-Known Cummins Weak Point

The biggest selling point of the Fleece kit is simple: it removes the OE-style grid heater and the infamous retaining nut that has become a known failure point on late-model Cummins engines. Instead of relying on the stock design, Fleece engineered a completely new high-flow intake horn and intake plate that utilize a robust coil-style heating element.

For diesel owners who tow heavy, daily drive their trucks, or rely on them for work, the peace of mind alone makes this upgrade attractive. Engine damage caused by hardware ingestion can quickly turn into a five-figure repair bill. Fleece’s redesigned system eliminates that risk while improving overall airflow into the engine.

Unlike some aftermarket alternatives, the Fleece setup was designed to retain factory functionality and maintain a clean OE-style fit and finish. The precision-machined cast aluminum intake horn and high-flow intake plate look right at home in the engine bay.

More Airflow, Better Response

While reliability is the headline feature, performance improvements are built into the package as well. The new intake horn and intake plate are engineered to reduce intake restriction and increase airflow, helping the 6.7-liter Cummins breathe easier. Fleece says the system improves throttle response while lowering intake restriction compared to the factory setup.

That means quicker turbo response, smoother power delivery, and improved drivability whether the truck is towing a trailer, running oversized tires, or simply commuting every day. The intake horn also incorporates a 1/8-inch NPT port for sensor installation, giving enthusiasts additional flexibility for aftermarket gauges or data monitoring.

Cold Weather Capability Wasn’t Forgotten

One of the biggest concerns whenever grid heater replacements hit the market is cold-weather performance. Delete-style solutions often compromise cold starts in northern climates, but Fleece engineered this kit specifically to retain reliable winter operation.

The standard configuration uses a single 700-watt heating element optimized for efficient placement within the intake air stream. According to Fleece, that setup has been validated for sustained startability down to 23 degrees Fahrenheit (-5 degrees Celsius).

For owners operating in extreme climates, Fleece also offers a Cold Weather Kit, part number FPE-CUMM-IAH-X2, which adds a second 700-watt heating element. Together, the dual-heater configuration has been tested for cold starts down to -35 degrees Celsius.

Testing was performed on a 2024 Ram 2500 using the block heater and fully charged 12-volt batteries, with Freedom Series 100-percent synthetic 10W-30 oil in the engine.

Fleece also points out that its system achieves comparable cold-weather startability with lower overall wattage than competing kits, reducing strain on the grid heater relay while still delivering dependable operation in brutal winter conditions.

Installation Designed For The Real-World Diesel Owner

Fleece didn’t just engineer a better intake horn—they also spent considerable time refining the installation process so it would be approachable for experienced DIY diesel enthusiasts and professional shops alike. The company estimates installation time at roughly four hours using common hand tools, including basic metric sockets, line wrenches, Allen keys, and a clip puller.

One of the standout features of the kit is how complete it is right out of the box. Every gasket, bolt, cable, plug, and fitting required for installation is included and organized in clearly labeled hardware packs with color-coded fasteners. The kit even includes intake runner, intake horn, throttle valve, EGR valve, and EGR crossover tube gaskets for both pickup and cab-and-chassis applications.

Installation begins with removing the factory intake horn, EGR components, fuel rail, and stock intake plenum to gain access to the problematic OE grid heater assembly. Fleece’s instructions walk owners through disconnecting the EGR crossover tube, throttle valve, MAP sensor, injector harnesses, and high-pressure fuel system components in a step-by-step format with detailed images throughout the 25-page instruction manual.

Unlike some aftermarket solutions that force owners into proprietary fuel system hardware, the Fleece kit is designed to reuse the factory high-pressure fuel lines. That means replacement parts remain easy to source nationwide and owners avoid the headaches associated with custom fuel plumbing.

Once the factory intake plenum is removed, the new high-flow Fleece intake runner plate installs in its place using supplied gaskets and hardware. The intake horn itself is then assembled with the factory throttle valve, MAP sensor, and temperature sensors before being bolted into position.

A major focus during development appears to have been maintaining OE-like fitment. The instructions specifically emphasize proper alignment around injector line clearance, oil dipstick positioning, and EGR crossover alignment to ensure everything fits cleanly without interference.

The electrical side of the installation is equally refined. The new coil-style heater utilizes upgraded power and ground cables with insulated protective boots over energized connections, eliminating the exposed terminals seen in some competing systems. The new heater cable routes directly to the factory grid heater relay, while the included ground cable ties into the negative battery terminal and intake horn assembly for a clean, factory-style appearance.

For cold-weather users adding the optional dual-heater upgrade, installation is integrated directly into the intake horn assembly process. Instead of installing the standard heater plug and 1/8-inch NPT plug, owners simply install the secondary heating element and crush washer in the designated port.

Before final startup, Fleece recommends performing a boost leak test to verify proper sealing and system integrity. Once complete, the result is an OE-quality installation that looks factory while delivering increased airflow, improved throttle response, and permanent elimination of the stock grid heater nut failure risk.

Broad Fitment Coverage

One of the most impressive aspects of the kit is its compatibility range. Fleece engineered the system to fit 2007.5-2024 Ram 2500, 3500, 4500, and 5500 trucks equipped with the 6.7-liter Cummins, including dual-alternator applications.

That wide-ranging fitment means owners don’t have to stress over selecting multiple versions for different model years. Fleece says the kit offers the broadest coverage of any intake horn and grid heater solution currently on the market.

Built For The Long Haul

Diesel enthusiasts are always searching for upgrades that improve reliability without sacrificing drivability, and that’s exactly where the new Fleece Performance Intake Horn and Grid Heater Kit lands. Rather than simply deleting factory components, Fleece engineered a complete system that protects the engine, improves airflow, preserves cold-weather operation, and maintains an OE-quality appearance.