Replace the OEM plastic-tank single-row radiator with an all-aluminum 2 or 3-row. Best single cooling mod for any XJ that sees heat.
The factory XJ radiator is a single-row aluminum core with plastic end tanks. After 15-20 years the plastic tanks crack and the core scales. The standard upgrades:
CSF 3-row aluminum (PN 2707): all-aluminum, three rows, direct fit. Considered the best value at ~$280. Made specifically for the XJ application with correct trans cooler fitting.
Mishimoto X-line (PN MMRAD-XJ-97X): all-aluminum, dual row but with thicker tubes. Slightly better claimed cooling, more expensive at ~$430.
Griffin / Be Cool: custom-fit aluminum, top-tier, $500+. Overkill for most.
The AW4 trans cooler integration matters — make sure your replacement has the right size fittings (5/16" tube) and that you replace the rubber lines while you're in there. A radiator failure that drops coolant also drops trans fluid into the engine bay; not catastrophic if caught.
For a stroker or any XJ with V8 swap, a 3-row all-aluminum is mandatory. For a stock 4.0L daily driver, a fresh OEM-style replacement (Spectra Premium, Denso) is fine and cheaper.
| Part | Vendor | Est. price |
|---|---|---|
| CSF 3-row aluminum radiator | CSF | ~$280 |
| Mishimoto X-line radiator | Mishimoto | ~$430 |
| Mopar trans cooler lines | Mopar | ~$50 |
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.