2021-2024 Jeep Wrangler Suspected Engine Coolant Leak TSB

Owners of 2021-2024 Jeep Wrangler, Gladiator, Grand Wagoneer, Wagoneer, Grand Cherokee, and Dodge Durango vehicles may experience a Jeep Wrangler engine coolant leak, indicated by a coolant odor or visible fluid leakage under the vehicle. Manufacturer communication S2307000002 Rev. A provides technicians with a comprehensive inspection procedure to accurately diagnose and pinpoint the source of such leaks.

Symptoms of a Coolant Leak

The primary indicators of a Jeep Wrangler engine coolant leak include:

• A distinct coolant odor emanating from the engine compartment.
• Visible fluid leakage observed underneath the vehicle when parked.

These symptoms suggest a potential issue within the cooling system that requires prompt attention to prevent further damage.

Diagnosis and Inspection Procedure

To identify the source of a suspected engine coolant leak, technicians are instructed to perform a thorough inspection, beginning with the Pressurized Coolant System Inspection process detailed in the Service Library. This involves pressurizing the cooling system to simulate operating conditions and make leaks more apparent.

A critical step in the diagnostic process is a visual inspection of the entire cooling system under pressure, utilizing UV light. This method helps to highlight coolant leaks that might not be easily visible to the naked eye. If the vehicle uses MOPAR 10yr coolant (which is purple), it will glow orange under UV light. If there's uncertainty about the coolant type or if its fluorescence has diminished, a Leak Detection Additive should be introduced into the system as per the Cooling Diagnosis and Testing Procedures (Coolant Leaks) in the Service Library.

Key components to inspect for leaks include:

• Radiator
• Hot bottle/coolant reservoir/expansion tank
• Front cover
• Water pump
• Thermostat
• Front cover coolant crossover
• Cylinder head gasket
• Cylinder block
• Cylinder head
• EGR cooler (if equipped)
• Oil filter adapter (OFA)
• HVAC heaters
• Trans oil cooler (TOC) coolant lines (if equipped)
• All cooling system hoses, gaskets, and connections

If coolant residue is found in lower areas of the engine compartment, technicians should inspect the cooling system parts located directly above to determine the precise leak source.

Important Warnings and What Owners Should Know

Owners should be aware of specific conditions related to coolant leaks:

• Water Pump Weep Hole: Some coolant residue may be present at the water pump weep hole plug area, which can be normal. However, coolant should not be actively dripping from this location. The presence of coolant in the weep hole alone does not confirm a faulty pump; a system pressurization test is necessary for accurate diagnosis.
• Warranty Repairs: This manufacturer communication, S2307000002 Rev. A, does not authorize warranty repairs. It serves as a guide for diagnosis based on past experiences.
• Seeking Assistance: If a solution cannot be found after following the outlined procedures, technicians are advised to contact the STAR Center or their Technical Assistance Center via TechCONNECT or eCONTACT ticket.

Owner Action

If you suspect a Jeep Wrangler engine coolant leak due to a coolant odor or visible fluid under your 2021-2024 Jeep Wrangler, it is recommended to have your vehicle inspected by a qualified service technician. They will follow the diagnostic steps outlined in manufacturer communication S2307000002 Rev. A to accurately identify and address the issue.

Source: NHTSA ID: 11001198