2018 Ram 2500 6.7 Cummins Intake Manifold Install Guide

Author: John Lee, SPELAB Mechanical Engineer. Updated on May 12, 2026.

Quick Answer: How Do You Remove and Install the Intake Manifold on a 2018 Ram 2500 6.7 Cummins?

To remove and install the intake manifold or intake horn on a 2018 Ram 2500 6.7L Cummins, let the engine cool, disconnect both batteries, remove the intake tube and related sensors, carefully move any components that block access, remove the factory intake horn or manifold assembly, clean the sealing surfaces, install the new gasket and upgraded part, then reconnect sensors, clamps, wiring, and fuel-related components as required by the kit.

On the 6.7 Cummins, many aftermarket upgrades are sold as an intake horn, intake manifold, grid heater delete plate, or all-in-one intake kit depending on the product design. The goal is usually the same: improve airflow into the engine, reduce restriction near the grid heater area, and create a stronger, cleaner intake path.

If you are upgrading instead of reinstalling the stock part, compare a direct-fit 6.7 Cummins intake horn or a complete 6.7 Cummins intake manifold kit before starting the job.

Intake Manifold vs Intake Horn on a 6.7 Cummins

Before removing parts, it helps to understand the terms. On many diesel engines, the intake manifold distributes air into the engine, while the intake horn directs charge air from the intake piping into the manifold area. On the 6.7 Cummins, aftermarket parts are often described as intake horns, intake manifolds, grid heater delete plates, or all-in-one intake kits depending on how much of the intake path they replace.

Part	Main Function	Why Owners Upgrade
Factory intake horn	Routes air into the intake manifold area	Can be restrictive and may collect soot or oil residue
Intake manifold / intake horn upgrade	Improves airflow path and reduces restriction	Better airflow support, cleaner layout, stronger construction
Grid heater delete or upgrade plate	Replaces or modifies the factory grid heater area	Reduces restriction and addresses grid heater bolt concerns

If your main concern is grid heater bolt failure, review this guide on grid heater bolt failure risk before choosing between a delete plate, heater-retaining upgrade, or full intake horn upgrade.

Why Remove or Upgrade the 2018 Ram 2500 6.7 Cummins Intake Manifold?

Most owners remove the intake manifold or intake horn for one of three reasons: maintenance, repair, or performance upgrade. A 2018 Ram 2500 6.7 Cummins may need intake service if the intake path is dirty, restricted, leaking, or being upgraded with a high-flow aftermarket kit.

Reason	What It Means	What to Inspect
Carbon and soot buildup	Oil vapor and soot can collect in the intake path	Intake horn, grid heater area, MAP sensor area, EGR path
Airflow restriction	The stock intake path may limit airflow on modified or towing trucks	Factory intake horn, grid heater plate, intake tube, boots
Grid heater concern	Some owners want to address grid heater bolt failure risk	Grid heater plate, bolt condition, intake port cleanliness
Performance upgrade	High-flow intake parts may support better airflow and throttle response	Intake horn, manifold kit, clamps, sensors, tuning compatibility
Leak or sensor issue	Loose clamps, bad gaskets, or dirty sensors can cause drivability symptoms	Gaskets, O-rings, connectors, MAP sensor, charge pipe boots

For a broader airflow upgrade path, compare related intake system parts instead of replacing one component blindly.

Grid Heater Note for 2018 Ram 2500 Owners

The 2018 Ram 2500 6.7 Cummins still uses the intake heater system for cold-start support. Many owners upgrade or delete the factory grid heater area because they are concerned about restriction, soot buildup, or grid heater bolt failure. However, cold-climate trucks may still need heater support, a block heater, strong batteries, and proper winter fuel practices.

If your goal is to address the grid heater area while upgrading the intake path, compare the 6.7 Cummins grid heater delete plate with heater-retaining options before choosing a setup.

For a more detailed decision guide, read whether to delete or upgrade the grid heater.

Tools Needed for 2018 Ram 2500 6.7 Cummins Intake Manifold Removal

Exact tools may vary depending on the kit, EGR configuration, grid heater setup, and whether fuel line access is required. Prepare your tools before opening the intake path.

10mm, 13mm, and 15mm sockets
Ratchet and extensions
Allen wrench set
Torque wrench
Flathead and Phillips screwdrivers
Hose clamp pliers
Pick tool for connectors and clips
Clean shop towels or dedicated intake port covers
Sensor-safe cleaner
Penetrating oil for stuck bolts
Container for any fluid drips if lines or hoses are removed
OBD scan tool for post-install code check

Safety and Preparation Before Removal

This job is not difficult for an experienced DIY owner, but it requires patience. The biggest risks are burns, fuel contamination, broken connectors, dropped hardware, and debris falling into the open intake port.

Park the truck on level ground.
Let the engine cool completely.
Disconnect both negative battery terminals.
Clean dirt and loose debris around the intake area before disassembly.
Take photos of sensor plugs, wire routing, brackets, and hose locations.
Cover the intake opening immediately once it is exposed.
Do not allow bolts, rags, carbon chunks, or tools to fall into the intake port.
Use new gaskets and seals if the kit includes them.

Cleanliness warning: Cleanliness is everything when working around the intake and high-pressure fuel system. Blow loose dirt away before disconnecting lines or brackets, and do not use paper towels to cover the intake port. Paper towels can tear, shed fibers, and leave debris behind. Use clean shop towels or a proper port cover instead.

Fuel system warning: If your installation requires fuel line or injector line removal, keep everything extremely clean. Even small debris can damage fuel system components. If you are not comfortable working near diesel fuel system components, use a qualified technician.

Step-by-Step Removal Guide

Step 1: Remove the Engine Cover and Intake Tube

Open the hood and remove the plastic engine cover if equipped.
Loosen the intake pipe clamps.
Remove the intake tube from the intake horn area.
Inspect the intake tube and boots for cracks, oil residue, or loose clamps.

Step 2: Disconnect Sensors and Harnesses

Disconnect any sensors attached to the intake horn or manifold area.
Do not pull on wires. Release the connector lock first.
Label or photograph each connector before removal.
Move the harness away from sharp edges and hot components.

If your upgrade includes a sensor relocation or angled connector, confirm the harness routing before final assembly. A loose or stretched connector can trigger fault codes after installation.

Step 3: Remove EGR-Related Tubes or Plates If Required

Some configurations may require removing EGR-related tubes, plates, or brackets to access the intake horn/manifold area. Work slowly and do not force stuck parts.

Remove only the components required for access.
Inspect EGR-related surfaces for carbon buildup.
Keep bolts organized by location.
Replace damaged gaskets instead of reusing crushed seals.

Compliance note: If your truck is street-driven, keep emissions equipment and local regulations in mind. Do not remove emissions-related parts unless the vehicle use and local rules allow it.

Step 4: Remove Fuel Line or Rail Components Only If Required

Some intake horn or manifold kits may require additional clearance around fuel lines or brackets. Not every installation requires the same fuel system disassembly.

Follow the kit instructions and factory service manual.
Clean the area before loosening any fuel-related fittings.
Cap or cover open lines if removed.
Do not allow dirt or debris into fuel system openings.
Recheck for fuel leaks after startup if any fuel connections were touched.

Step 5: Remove the Factory Intake Horn or Manifold Assembly

Locate the mounting bolts around the intake horn or manifold assembly.
Loosen bolts evenly instead of removing one side under stress.
Gently lift the assembly away from the engine.
Do not pry aggressively against sealing surfaces.
Cover the open intake port immediately.

Debris warning: This is the most important part of the job. Any bolt, washer, carbon chunk, gasket fragment, or rag fiber that falls into the intake can create serious engine damage.

Step 6: Inspect the Removed Parts

Check the old gasket for crushing, cracks, or uneven sealing.
Inspect the intake horn for carbon buildup or oil residue.
Inspect the grid heater area if exposed.
Look for loose hardware, damaged bolt holes, or warped mating surfaces.
Clean the sealing surface before installing the new part.

Installing the SPELAB Intake Manifold or 6.7 Cummins Intake Horn

The SPELAB intake upgrade is designed to improve airflow and clean up the intake path. Depending on your setup, it may be paired with a grid heater delete or upgrade plate, EGR plate, sensor connector, or intake horn components.

For the full product application, review the SPELAB 6.7 Cummins intake manifold upgrade before installation.

Step 1: Prepare the New Part

Compare the new part with the factory part before installation.
Confirm all ports, bolt holes, and sensor locations match your application.
Install the new gasket or O-ring supplied with the kit.
Make sure the gasket is seated correctly and not pinched.

Step 2: Position the Intake Manifold or Intake Horn

Place the new part onto the clean mating surface.
Start all bolts by hand to avoid cross-threading.
Tighten bolts evenly in two stages instead of fully tightening one side first.
Use a crisscross pattern where the kit instructions recommend it.
Use the torque specs supplied with your kit or factory service manual.

Torque note: Many 6.7 Cummins intake horn or grid heater plate installations use around 18 lb-ft, or about 24 Nm, for intake-related bolts. Some kits specify 18–20 lb-ft. Always follow the SPELAB instruction sheet or factory service manual for your exact configuration. Over-tightening can strip threads or distort the sealing surface. Under-tightening can cause boost leaks.

Step 3: Connect the Sensor Harness

Install the sensor connector or harness supplied with the manifold if included.
Confirm the connector clicks fully into place.
Route the harness away from hot exhaust parts and sharp edges.
Secure the harness with zip ties if needed.

Step 4: Install the Grid Heater Delete or Upgrade Plate If Included

If your setup includes a grid heater delete or upgrade plate, confirm whether your truck needs heater function for cold starts. A full delete may be suitable for warm climates or performance-focused builds, while cold-climate daily drivers may need heater-retaining options or other cold-start support.

After installation, scan for intake air heater-related codes such as P2609 if the Check Engine Light appears. P2609 can relate to the intake air heater system performance, wiring, relay, heater circuit, or cold-start operation, so do not assume the new part is bad before checking connections.

Step 5: Reinstall Intake Tube, Hoses, and Brackets

Reinstall the intake tube and tighten clamps evenly.
Reconnect any brackets, hoses, and EGR-related components that were removed.
Check that no hose is twisted, pinched, or rubbing against sharp edges.
Make sure all clamps are seated behind the bead of the pipe.

Step 6: Reconnect Batteries and Start the Engine

Reconnect both negative battery terminals.
Cycle the key and check for warning lights.
Start the engine and let it idle.
Listen for hissing, whistling, or air leaks.
Check for fuel leaks if any fuel connections were disturbed.
Use an OBD scan tool to check for fault codes.

Common Installation Mistakes to Avoid

Mistake	Why It Matters	How to Avoid It
Leaving the intake port uncovered	Debris can fall into the engine	Cover the port immediately after removal
Using paper towels in the intake opening	Paper can tear, shed fibers, and leave debris behind	Use clean shop towels or a dedicated port cover
Reusing damaged gaskets	Can cause boost leaks or rough running	Use new gaskets and O-rings when supplied
Forgetting a sensor connector	Can trigger fault codes or poor drivability	Take photos and confirm every connector is locked
Over-tightening bolts	Can strip threads or distort aluminum sealing surfaces	Use a torque wrench and follow the instructions
Routing harnesses near heat	Can melt wiring or cause intermittent faults	Secure wires away from hot exhaust and sharp edges
Ignoring cold-start needs	Grid heater changes can affect winter starts	Choose the correct heater delete or heater-retaining setup

Post-Installation Checklist

After installing the intake manifold or intake horn, do not assume the job is done until the truck has been checked under idle and light driving conditions.

Confirm no tools, bolts, rags, fibers, or gasket pieces are near the intake port.
Verify every sensor connector is fully seated.
Check that the intake tube and clamps are tight.
Listen for hissing or whistling under idle and light throttle.
Check for fuel leaks if fuel connections were removed.
Scan for codes after the first startup.
Watch for P2609 or other intake air heater-related codes if grid heater wiring was changed.
Inspect gasket areas after the first heat cycle.
Recheck clamps after a short test drive.

If the truck shows a Check Engine Light, rough idle, boost leak sound, hard start, P2609 code, or abnormal throttle response after installation, recheck connectors, gaskets, clamps, sensor routing, heater circuit connections, and intake sealing before replacing parts.

Expected Results After an Intake Manifold or Intake Horn Upgrade

A well-installed intake horn or manifold upgrade may support smoother airflow, better throttle response, and a cleaner intake layout. The biggest benefit depends on the condition of the original parts and the rest of the truck’s setup.

Do not expect the intake manifold alone to magically add major horsepower or fuel economy. Real gains depend on airflow demand, tuning, turbo condition, fuel system health, intercooler efficiency, exhaust flow, and how the truck is used.

For a stock daily driver, the main benefit may be reliability and reduced restriction. For towing or modified trucks, the upgrade can be part of a larger airflow package. If the truck is tuned or used for heavy towing, monitor EGT, boost behavior, and cold-start performance after any intake-side change.

Related Guides

FAQ

Q: Is the 2018 Ram 2500 6.7 Cummins intake manifold the same as the intake horn?

A: Not exactly. The intake horn directs air into the intake manifold area, while the manifold distributes air into the engine. On 6.7 Cummins aftermarket parts, the terms are sometimes used together because many upgrades affect the same intake path.

Q: Why should I upgrade the 6.7 Cummins intake horn or manifold?

A: Common reasons include reducing intake restriction, cleaning up carbon buildup, addressing grid heater concerns, improving airflow support, and upgrading the intake path for towing or performance use.

Q: Can I remove the 6.7 Cummins intake manifold myself?

A: Yes, if you have intermediate mechanical experience and the right tools. The job requires careful connector removal, clean work around the intake opening, proper gasket placement, and post-install leak checks. If fuel system components must be removed, professional help may be safer.

Q: Do I need to remove the fuel rail to install a 6.7 Cummins intake horn?

A: It depends on the kit and the access required. Some installations may need fuel line or bracket clearance, while others may not. Always follow the kit instructions for your exact part and model year.

Q: What torque should I use for a 6.7 Cummins intake horn?

A: Many 6.7 Cummins intake horn or grid heater plate installs use around 18 lb-ft, or about 24 Nm, for intake-related bolts. Some kits specify 18–20 lb-ft. Always follow the instructions for your exact kit and tighten evenly to avoid leaks or stripped threads.

Q: Can a 6.7 Cummins intake horn install cause P2609?

A: P2609 is related to intake air heater system performance. It may appear if the grid heater circuit, heater relay, wiring, or connector is not working as expected. If the code appears after installation, inspect the heater-related connections before assuming the intake horn is the problem.

Q: Should I replace the gasket when reinstalling the intake manifold?

A: Yes. Reusing a compressed, damaged, or dirty gasket can cause air leaks. Use the new gasket or O-ring supplied with the kit whenever possible.

Q: Will an upgraded intake manifold add horsepower?

A: It can support better airflow, but the manifold alone does not guarantee major horsepower gains. Results depend on turbo setup, tuning, fuel delivery, exhaust flow, and the condition of the original intake system.

Q: What is the biggest installation risk?

A: The biggest risk is dropping debris, bolts, gasket material, fibers, or tools into the open intake port. Cover the intake opening immediately and keep the work area clean.

Q: Do I need a grid heater delete with a 6.7 Cummins intake horn upgrade?

A: Not always. Some owners choose a grid heater delete or upgrade plate to reduce restriction or address bolt failure concerns. Cold-climate owners should consider cold-start needs before deleting heater function.

Q: What should I check after installation?

A: Check for intake leaks, loose clamps, fuel leaks if lines were disturbed, sensor connection problems, fault codes, P2609, abnormal idle, hard start, or poor throttle response.

Q: Will this guide apply to all 6.7 Cummins years?

A: The general process is similar, but model-year details, sensors, EGR routing, grid heater setup, and kit hardware can vary. This guide is written for a 2018 Ram 2500 6.7L Cummins, so always confirm fitment before ordering parts.

John Lee

Mechanical Engineer | 10+ Years Experience

John has spent the last decade engineering and testing high-performance automotive components. Specializing in drivetrain durability and thermal management across Powerstroke, Cummins, and Duramax applications, he bridges the gap between OEM limitations and aftermarket performance. His philosophy: "Factory parts are just a starting point."