1989-1993 Dodge 5.9L Cummins Air Intake Accessories

Intake accessories on the 1989-1993 Ram 5.9L Cummins

On a first-gen truck, the intake accessories are the small parts that hold the air path together: grid heater gasket sets, clamps on the intercooler plumbing, and silicone boots with stainless clamps on built trucks. The grid heater is the center of it. It sits sandwiched between the cast air horn and the intake manifold on its own gasket set, and it handles cold starts on the 5.9L Cummins in place of glow plugs, cycling only when intake air drops below 59°F. One more intake-side part is easy to forget. The AFC boost reference line taps the intake manifold and runs to the injection pump on its own banjo bolt. That line ties boost to fueling, so treat its fitting with the same care as the gaskets when the manifold area is apart.

What wears out

Age does the damage here. Grid heater gaskets leak, and the heater element wears. A leaking stack shows up as a boost hiss at the horn and oily residue around the horn flange. A worn element shows up as slower cold starts, and since the grid only runs below 59°F, that symptom only appears in cold weather. On intercooled mid-1991 to 1993 trucks, the boots and clamps between the turbo, the cooler and the horn are the other joints holding boost.

Stock replacement vs. upgrade

Most of this page is stock replacement: a factory heater grid and the gaskets that seal the stack around it. The one place you pick a direction is couplers and clamps. Documented first-gen builds run silicone boots with stainless clamps on the intercooler plumbing, and the silicone coupler here fits that approach as long as its diameter matches your pipe.

What we carry

• Heater grid: the genuine Cummins 3929108 intake air heater grid, listed for 1989-1998 5.9L Cummins.
• Gaskets: the Alliant Power AP0058 intake grid heater gasket set, listed for 1989-2007, and the MAHLE MS12435 intake manifold gasket set, listed for 1989-2002.
• Coupler and clamp: an S&B 4-inch silicone coupler with clamps and the BD Diesel high-torque hose clamp.
• Filter care: the S&B 88-0008 Precision II air filter cleaning and oil kit.
• Sensor: the XDP XD1003 throttle position sensor, listed for 1990-1993.

For complete intake systems, start at our intakes page and check first-gen fitment on each listing.

Fitment notes

Read the year range on every listing. The heater grid covers 1989-1998, the gasket sets run as late as 2002 or 2007, and the throttle position sensor is listed for 1990-1993, which leaves 1989 trucks out. Couplers are sized by diameter, so measure the pipe you are joining before you order the 4-inch S&B coupler. Intake plumbing also differs between non-intercooled 1989-early 1991 trucks and intercooled mid-1991-1993 trucks, and a 1991 can be either, so look for the factory intercooler rather than trusting the title year. Verify by VIN when in doubt.

Frequently asked questions

Should I replace the grid heater gaskets when I install a new grid?

Yes. The grid sits between the air horn and intake manifold on its own gasket set, and aged gaskets at that joint are a known source of boost leaks and oily residue at the horn flange. Pulling the grid disturbs both sides of the stack, so seal it back up with fresh gaskets.

What is the S&B cleaning and oil kit for?

It is for washable, oiled air filters. The factory airbox uses a paper element, which you replace by part number: Fleetguard AF455M or WIX 46343 for 1989-1992 and Fleetguard AF25023 or WIX 46338 for 1993. Only use the kit if you run an oiled filter.

Does the XDP throttle position sensor fit a 1989 Ram?

Its listing covers 1990-1993 5.9L Cummins trucks, so a 1989 falls outside the listed range. Run your truck through the fitment checker on the product page, or call us with your VIN before ordering.

Not sure what fits? Call the shop at the number in the header, or use the fitment checker on any product page. We install everything we sell.