The 3.6L Pentastar in the Gladiator JT does not have a serviceable inline fuel filter — the filter is integrated into the in-tank fuel pump module and replaced only when the pump fails or at high mileage.
The JT's fuel system is more straightforward to maintain than it looks. Stellantis doesn't specify a standalone fuel filter service interval because the filter is part of the pump module — it only comes out with the pump. In practice, this means most JT owners don't touch the fuel filter until 100,000+ miles or when a fuel delivery symptom appears (hard starts, rough idle, hesitation at throttle).
What you can do proactively: throttle body cleaning and a fuel system additive. Both are worth doing at 30,000–50,000-mile intervals and take under an hour combined.
The Pentastar's throttle body accumulates carbon deposits from crankcase vapor recirculation (PCV). Enough buildup causes rough idle and sluggish tip-in.
1. Park with the engine cold. Locate the throttle body on the driver's side of the intake — it's the round aluminum housing where the large air intake hose connects.
2. Disconnect the intake air hose by loosening the clamp and pulling the hose free. Stuff a clean rag in the hose end to prevent debris ingestion.
3. With the throttle blade closed, spray a small amount of throttle body cleaner onto a clean shop rag and wipe the inner bore and blade edges. Do not spray cleaner directly into the throttle body on a drive-by-wire engine — the pressure can force debris past the blade into the intake.
4. If deposits are heavy: have an assistant hold the accelerator pedal to open the blade (ignition on, engine off), and carefully wipe the backside of the blade and bore with a solvent-soaked rag.
5. Reconnect the intake hose and clamp. Start the engine — expect a rough idle for 30–60 seconds as residual cleaner burns off.
Adding Sea Foam or a similar concentrated fuel system cleaner to a full tank of fuel once a year cleans injector deposits and keeps the fuel pump pickup screen clear of varnish buildup. Follow the label instructions — for Sea Foam, typically 1 oz per gallon of fuel capacity (the JT holds 22.5 gallons, so a full can of Sea Foam is appropriate).
You won't know the in-tank filter is clogged until the pump shows symptoms:
A rough check: at key-on (not cranked), listen for the fuel pump prime — a faint whirr from under the truck for 2–3 seconds. If you don't hear it, the pump is suspect. Verify with a fuel pressure gauge at the Schrader valve on the fuel rail — 3.6L Pentastar spec is 55–60 PSI at idle.
Throttle body cleaning: ~$8–12 for a can of CRC or similar. Your time: 30 minutes. Worth doing every 30,000 miles.
Sea Foam or fuel system additive: ~$10–15 per treatment. Once a year at fill-up.
In-tank fuel pump/filter module: ~$200–350 for OEM Mopar. Labor at a shop to drop the tank and replace the module is 2–3 hours, adding $150–300. A symptom-free pump doesn't need replacement.
| Part | Vendor | Est. price |
|---|---|---|
| Mopar Fuel Filter (in-tank, 2020-2024 JT) | Mopar | ~$45 |
| CRC Throttle Body Cleaner | CRC | ~$8 |
| Sea Foam Motor Treatment (fuel system cleaner) | Sea Foam | ~$14 |
Written and maintained by an AZ wheeler and driveway wrencher. Always cross-reference your factory service manual — modifications affect vehicle safety and warranty. Work at your own risk.