If your Full Size Jeep runs warm at idle or your heater underperforms in traffic, this FlowKooler pump fixes the low-RPM flow bottleneck. An 8-blade, CNC-machined impeller reduces plate-to-impeller clearance to build higher head pressure and move more coolant at idle—helping the radiator and heater core exchange heat faster. At cruising RPM the pump regulates flow so you don’t over-circulate. The anodized impeller resists corrosion/electrolysis, and the aluminum housing cuts weight versus typical OE replacements. Manufacturer-stated results show significantly increased (up to ~2×) idle flow compared with stock, improving heat soak recovery and cabin heat-up.

Typical symptoms this solves: temp creep at idle/stop-and-go, weak heater at low RPM, hot climbs/trail crawling, stagnant coolant before thermostat opens.

Features & Benefits:

• High idle flow: Reduced impeller clearance + 8-vane design increases coolant volume and head pressure at low RPM for more effective heat transfer.
• Stable at higher RPM: Flow behavior is tempered beyond ~3,500 RPM to avoid over-pumping.
• CNC-machined impeller: Precision 8-blade design for efficient, repeatable performance.
• Type II, Class II anodized impeller: Corrosion and electrolysis resistance for long service life.
• Lightweight aluminum construction: Durable, OE-location replacement.
• Gasket included for a straightforward install.
• 2-year limited warranty.

What’s Included:

• Water pump assembly
• Gasket

Install Notes:

• Direct-fit at the factory location; reuse your original pulley/hardware where applicable.
• Follow AMC torque specs and sealant procedures per the service manual.
• Verify belt alignment/tension after install.

Fits: AMC Inline-6 4.2L (258)

• 1980–1983 Wagoneer
• 1984–1986 Grand Wagoneer
• 1980–1983  Cherokee (SJ)
• 1980–1987  J-Series Trucks (J10/J20)