Heater Grid Delete

Heater Grid Delete for the 5.9L Cummins


heater gird delete The Cummins diesel does not use glow plugs during startup. Rather, the 5.9L Cummins is equipped with a heater grid, located directly between the air horn and intake manifold. The heater grid heats incoming air during startup to ensure quick starting, especially in cold weather. The heater grid is a mildly restrictive unit, and performance gains can be had by removing it (see the image located at the bottom of the page to understand the source of restriction.)


Otherwise Known As:

heater grid, heater grid mod, heater grid delete

How It Works:

A heater grid delete kit replaces the factory, restrictive heater grid with a free flowing riser. This makes the transition between the air horn and intake manifold smooth and unrestricted, resulting in increased air flow and performance gains. While gains are relatively small, this modification is very affordable, with most kits costing under $100.00 dollars, and some available for significantly less.


• Many kits are available for under $100.00, making this an affordable modification.
• Increased airflow and slight performance increase.


• May trigger trouble codes (check engine light).
• Difficult cold weather starting.

Possible Problems:

• Not recommended for cold climate operation, as without the heater grid the engine may experience starting problems if the climate is too cold. Don't forget to replace the gaskets during installation.
• May not be compatible with some EGR equipped trucks.

Est. Gains:

5 - 15 hp, marginal fuel economy gain.


1998.5 - 2007 5.9L Cummins

Additional Info:

If you live in a region where the temperature often drops below freezing, you may want to keep your heater grid in tact. If you really want to perform this modification but live in a cold climate area, consider removing/reinstalling the heater grid seasonally. A block heater may also help with starting in cold weather without a heater grid.


Factory Cummins heater grid

Factory Cummins heater grid. Deleting the grid makes the transition between the air horn and intake manifold smooth & unrestricted.








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Diesel Tuner

7.3L Powerstroke EBV Delete

Cummins J Hook