On most Jeep 3.6L Pentastar engines, the oil cooler is part of the oil filter housing assembly in the V of the engine, below the upper and lower intake manifolds. Replacement is not technically exotic, but it rewards patience: plastic connectors get brittle, intake ports must stay clean, and the new housing must be torqued evenly.
Before You Start
This guide is for planning and owner education. Exact fasteners, hose routing, sensors, and torque specs vary by model year and Jeep platform. Verify the procedure with factory service information for your exact VIN, work on a cold engine, support the vehicle safely, disconnect the negative battery cable, and do not open the cooling system while hot.
What You Are Replacing
The assembly sits between the cylinder heads, under the intake. It carries the oil filter, oil cooler passages, oil pressure and temperature sensing points on many versions, and coolant connections for the heat exchanger. A leak often leaves oil pooled in the engine valley and can run down the rear of the engine, making it look like a rear main seal leak.
Oil Filter Adapter / Oil Cooler Replacement Diagram
Parts and Tools
Parts
- Replacement oil filter housing / oil cooler assembly
- Fresh intake manifold gaskets or seals
- New oil filter and engine oil
- Correct coolant for your Jeep
- Replacement sensors or pigtails if damaged
- Shop towels, brake cleaner, and port covers
Tools
- Metric socket set, extensions, and wobble joints
- Torque wrench that reads inch-pounds
- Pick tools for seals and electrical locks
- Hose clamp pliers or angled pliers
- Coolant drain pan and oil drain pan
- Labeling tape for hoses and connectors
Typical Torque Reference
Use these as common reference values only. Always confirm against service data for your exact model year, because Jeep applications and replacement assemblies can differ.
| Fastener | Typical value | Caution |
|---|---|---|
| Oil cooler / filter housing to engine block M6 bolts | 12 Nm / 9 ft-lb / 106 in-lb | Use an inch-pound wrench and tighten evenly. Do not crush the seals. |
| Upper intake plenum bolts | About 89 in-lb | Follow the intake tightening sequence for your year. |
| Lower intake manifold bolts | About 106 in-lb | Install with clean, dry seals unless the service manual says otherwise. |
| Oil filter cap | 25 Nm / 18 ft-lb on many caps | Overtightening the cap is a common housing killer. |
Replacement Steps
Confirm the leak source
Remove the engine cover and inspect the valley below the oil filter housing with a light. Oil in the valley, oil smell after driving, or oil running down the rear of the block often points to the housing. Clean the area first if the leak path is unclear.
Prepare the Jeep
Let the engine cool completely. Disconnect the negative battery cable. Drain enough coolant to lower the level below the cooler connections, and drain the engine oil if the replacement assembly or your work plan requires it. Keep pets away from coolant.
Remove the air intake parts
Remove the engine cover, air inlet tube, air box connections as needed, and any brackets or hoses that block the upper intake. Label vacuum lines and electrical connectors before unplugging them.
Remove the upper intake plenum
Disconnect the throttle body connector and related vacuum or EVAP lines. Remove the upper plenum bolts in a sensible reverse sequence, lift the plenum free, and set it somewhere clean. Cover open intake passages immediately.
Remove the lower intake manifold
Unplug remaining sensors or harness retainers that cross the lower intake. Remove the lower intake bolts, lift the lower manifold straight up, and cover every intake port with clean lint-free towels or port covers. Nothing should fall into the engine.
Disconnect the cooler assembly
Unplug the oil pressure and oil temperature sensors if equipped. Release coolant hoses carefully; old quick-connects and plastic fittings can break. Remove the cooler mounting bolts and lift the assembly out of the valley.
Clean the valley and sealing surfaces
Remove pooled oil and coolant from the valley. Clean the block sealing surface without gouging it. Do not scrape debris into oil or coolant passages. Compare the new assembly to the old one before installation.
Install the new housing
Make sure the seals are correctly seated and dry unless the part maker says otherwise. Lower the new housing squarely into place, start all bolts by hand, then snug them gradually in a crisscross pattern before final torque.
Reinstall the intake assemblies
Remove the port covers only when you are ready to install the lower intake. Use fresh intake seals, seat the manifolds evenly, and torque the fasteners in the specified sequence. Reconnect every hose, sensor, bracket, and harness retainer.
Refill, bleed, and test
Install a new oil filter, refill oil and coolant, reconnect the battery, and start the engine. Watch for oil and coolant leaks while it warms up. Bleed the cooling system according to Jeep service instructions, road test, cool down, and recheck both fluid levels.
Common Mistakes to Avoid
- Leaving intake ports uncovered while cleaning the valley.
- Reusing flattened or swollen intake seals.
- Using a foot-pound torque wrench where an inch-pound wrench is needed.
- Pinching an O-ring during housing installation.
- Forgetting to top off or bleed the cooling system after the repair.
- Mistaking residual oil in the valley for a new leak after the first drive.
After the First Heat Cycle
Let the Jeep cool completely, then inspect the valley, bellhousing area, coolant hoses, and oil filter cap. Check oil and coolant levels again. A clean valley after a few drives is the best sign the repair is settled.
References Used
This page was written as a practical guide and cross-checked against factory-service-style oil filter housing installation notes and replacement-part installation guidance. Always use the official service manual for final specifications.