If you own a Dodge/RAM truck equipped with the 6.7L Cummins engine, you’ve likely heard about the factory grid heater issue. What was originally designed to improve cold-weather starting has become one of the most discussed reliability concerns among RAM 6.7L diesel owners. In some cases, the factory grid heater bolt can loosen, overheat, and even partially melt before breaking free. If this happens, it can allow debris to enter a cylinder and cause extensive damage.
To address this concern, Fleece Performance Engineering developed its intake manifold and grid heater upgrade FPE-CUMM-IHK-0724. This innovative system eliminates the factory failure point while maintaining cold start functionality and maximizing airflow through the intake system.
What Is the Grid Heater Issue on 6.7L Diesel Trucks with the Cummins Engine?
The factory grid heater is mounted in the intake path and helps warm incoming air while starting. Though effective for cold-weather operation, the factory design uses a bolted connection (holds the bus bar to the manifold plate) that can become a failure point over time.
When the connection fails, the steel nut or portions of the mounting hardware can be drawn into the engine, potentially causing catastrophic internal damage. For many owners, this risk alone makes upgrading the factory setup a worthwhile investment.
Because of this issue, the grid heater upgrade has become a widely discussed preventative maintenance and reliability modification for RAM trucks with the 6.7L Cummins engine.
How Does the Fleece Intake Manifold & Grid Heater Upgrade Work?
Rather than simply deleting the factory grid heater, Fleece redesigned the entire intake assembly to reduce restriction and improve airflow while maintaining cold-start functionality. Their system combines a cast aluminum intake assembly, upgraded intake plate, a 700-watt coil heating element, wiring harnesses, hardware, and all required gaskets into a complete installation package.1,2
This design allows owners to address a known weak point without sacrificing reliable starts in colder climates.
Heavy-Duty Construction Built for Long-Term Reliability
One of the first things that stands out about the Fleece intake manifold is its construction. Made from precision-machined cast aluminum, the manifold delivers a durable, factory-style appearance while offering the strength expected from a premium diesel performance component.
The smooth casting and precision machining provide a professional fit and finish that blends seamlessly into the engine bay. Fleece also incorporates a threaded port for an optional secondary heater assembly, providing flexibility for trucks operating in extreme cold-weather environments.
For owners not using the optional heater, the supplied plug features a pre-drilled 1/8-inch NPT port that can be used for sensors, injectables like water meth or nitrous, or auxiliary monitoring equipment.
Does the Fleece Grid Heater Upgrade Affect Cold Starts?
Many intake upgrades focus on performance, but the Fleece system takes a balanced approach.
By removing the restrictive OE grid heater arrangement and redesigning the intake path, airflow through the intake system is improved while still retaining cold-start functionality. The primary heating element is positioned directly in the intake airstream for efficient operation during cold weather.
The system uses a 700-watt coil heater and can be configured with an optional secondary heater for additional cold-weather capability. According to Fleece, with the optional secondary heater installed, the system offers proven startability down to -31°F (-35°C).1
For many owners, this makes the upgrade a reliability improvement first and an airflow enhancement second.
What Comes With the Fleece Intake Manifold & Grid Heater Upgrade?
Another standout feature of the Fleece Intake Manifold & Grid Heater Upgrade is the completeness of the kit.
Rather than forcing installers to source additional components, Fleece includes the hardware, wiring, and gaskets needed for full installation.
Components include:
- Cast Aluminum Intake Manifold
- Upgraded Intake Plate
- 700-Watt Coil Heating Element
- Wiring Harnesses
- Installation Hardware
- Intake Gaskets
- Intake Runner Gaskets
- Throttle Valve Gaskets
- EGR Valve Gaskets
- Crossover Tube Gaskets
The kit also includes loom-protected, heat-shrunk wiring with protective boots and pre-labeled connections to simplify installation.
Additional Features Owners Will Appreciate
Fleece designed this system with practicality in mind. The upgrade reuses the factory high-pressure fuel injector lines, eliminating the need for custom replacement lines. The kit also includes an intake air temperature sensor extension harness for applicable cab-and-chassis models.2
These details help streamline installation while maintaining compatibility with factory components.
Is a Grid Heater Upgrade Worth It for Your 6.7L Truck with the Cummins Engine?
For many diesel owners, the Fleece Intake Manifold and Grid Heater Upgrade delivers the best of both worlds. It removes a commonly discussed factory failure point while improving airflow and maintaining cold-weather functionality.
Benefits include:
- Eliminates The Failure-Prone Factory Grid Heater Design
- Improves Intake Airflow
- Retains Cold-Start Capability
- Heavy-Duty Cast Aluminum Construction
- Complete Installation Package
- Reuses Factory Fuel Injector Lines
- Supports Optional Secondary Heater Installation
- Provides Peace Of Mind For Long-Term Ownership
Whether your truck is a daily driver, tow rig, work truck, or performance build, this upgrade helps address one of the most common concerns associated with the 6.7L platform.
What is The Best Solution for the 6.7L RAM Grid Heater Problem?
The factory grid heater has become one of the most discussed reliability concerns for Dodge RAM 2500/3500/4500/5500 trucks with the 6.7L Cummins engine. As a result, manufacturers have developed a solution that addresses the issue while preserving the cold-start performance that diesel owners rely on. The Fleece Intake Manifold and Grid Heater Upgrade represents one of the more comprehensive approaches, combining improved airflow, integrated heating technology, and a redesigned intake system to eliminate a common failure point without sacrificing functionality.
Sources
1 https://www.fleeceperformance.com/fleece-performance-intake-and-grid-heater-kit.html
2 https://www.fleeceperformance.com/media/wysiwyg/FPE-2026-160_FPE-CUMM-IHK-0724.pdf