1998 Jeep Cherokee XJ 4.0L Engine | OEM Used Manual Transmission Donor Variant
$1,225.00
At a Glance
- Condition: OEM used, 1998 XJ manual donor sourced
- Availability: In stock, 1998 XJ manual donor sourced engine only
- Shipping: Free shipping to all 50 states via freight pallet, 5 to 10 business days
- Engine only (not the complete vehicle)
- 1998-specific donor (HO era, OBD-II compliant, AX-15 manual configuration)
- Cylinder head casting code 7120 (pre-0331 era, lower crack risk)
- Compatible with all 1996 to 2001 XJ, Wrangler TJ, Grand Cherokee ZJ
- 100% fitment verified before every order ships
- No core charge required
- Backed by a 15 day replacement warranty against manufacturing defects
Description
About the 1998 Jeep Cherokee XJ 4.0L Engine
This is the alternate listing for our 1998 Jeep Cherokee XJ 4.0L engine, sourced from a manual-transmission XJ donor configuration. Experience the proven power of the legendary HO 4.0 Inline-6 with this 1998-sourced engine assembly, positioned for buyers who originally had or want a manual-transmission XJ build.
Important Note: This listing is for the engine only, not the complete 1998 Jeep Cherokee vehicle. The page title references the “1998 XJ” because the engine is sourced specifically from a 1998 XJ donor.
Why a Manual-Donor Variant
For most XJ Cherokees, the AX-15 5-speed manual transmission was a less-common option compared to the AW4 4-speed automatic. Some buyers specifically want a 1998 4.0 sourced from a manual donor configuration because:
- Engine internals can show different wear patterns when paired with manual transmissions versus automatics, sometimes resulting in cleaner internals in lower-mileage manual configurations
- Manual donor enthusiasts prefer the lineage of an engine that came from a manual-transmission XJ
- AX-15 swap builders often want the engine that originally came with the AX-15 to ensure flywheel and clutch interface consistency
That said, the engine itself is mechanically identical to the automatic-donor variant. The primary differentiation is the donor configuration history.
1998 Jeep Cherokee XJ 4.0L Engine Specifics
The 1998 Jeep Cherokee Classic XJ 4×4 4.0L Engine is a high-performance Inline-6 cylinder engine. It boasts a displacement of 4.0 liters (242 cu in) and 190 horsepower at 4,600 RPM. The engine features a cast iron block and cast iron cylinder head, with sequential multi-port fuel injection (MPFI). This particular variant is sourced from a 1998 XJ Cherokee paired with the AX-15 5-speed manual transmission, providing the original manual-transmission donor configuration.
Compatible Vehicles
This engine is specifically suited for the 1998 Jeep Cherokee Classic XJ. However, it can also fit other Jeep models with similar specifications:
- Jeep Cherokee XJ: 1996 to 2001 (OBD-II era, direct cross-fit)
- Jeep Wrangler TJ: 1997 to 2006 (different intake manifold orientation)
- Jeep Grand Cherokee ZJ: 1996 to 1998 (OBD-II era ZJ)
- Jeep Comanche MJ: With appropriate harness (1998 era)
Please ensure to check the compatibility of your vehicle before purchasing. Cross-installation between Renix-era (1987-1990) and HO-era (1991-plus) requires harness and ECU changes; this 1998-sourced engine is HO-era and compatible with HO-era applications only.
Key Features
The 1998 Jeep Cherokee Classic XJ 4×4 4.0L Engine is renowned for its durability and reliability. Key features include:
1. High-Performance: With 190 horsepower and 225 lb-ft of torque, this engine delivers solid performance ensuring a smooth and comfortable ride for trail use, daily driving, and light hauling.
2. Fuel Efficiency: Despite its power, the engine is designed to be reasonably fuel-efficient. 1998 XJ Cherokee with 4.0 typically delivers 16 to 19 mpg city / 20 to 23 mpg highway.
3. Durability: The engine cast iron block and head contribute to its durability, ensuring it can withstand harsh conditions and last for years. The 7120 head casting used on 1998 production is considered more reliable than the later 0331 casting.
4. Manual Transmission Donor: Originally paired with the AX-15 5-speed manual in a 1998 XJ Cherokee. Ideal for buyers continuing manual-transmission builds or restoring an AX-15-equipped XJ.
5. Off-Road Capabilities: The 4×4 drivetrain origin and torque-rich Inline-6 character make this engine ideal for off-road adventures, providing the low-end power needed for crawling and trail work.
6. Easy Installation: The engine is designed to drop into compatible XJ / TJ / ZJ chassis with appropriate ECU and harness. Simple OHV pushrod design makes installation more straightforward than modern overhead-cam alternatives.
Use Cases
This 1998 XJ 4.0 manual-donor variant is ideal for:
- AX-15 manual transmission XJ owners wanting a matching donor engine
- Manual transmission swap builders continuing manual lineage
- Restorers of manual-transmission 1998 XJ Cherokees
- Budget-conscious enthusiasts wanting the same fundamental 1998-vintage engine at the lower price point
Comparison Across Our Three Jeep 4.0 Listings
| Listing | Price | Differentiation |
|---|---|---|
| Primary 1998 XJ | $800 | 1998 XJ donor, automatic transmission origin (AW4 era) |
| This Listing | $800 | 1998 XJ donor, manual transmission origin (AX-15 era) |
| Main Multi-Year | $1,999 | Multi-year (1991 to 2006), full inspection paperwork, premium documentation |
Drive 1998 XJ vintage energy with this engine. Its power, performance, and durability make it a valuable addition to your XJ project, ensuring an unforgettable driving experience characteristic of Jeep legendary “Immortal Six.”
What Ships and What Does Not
| Item | Details |
|---|---|
| INCLUDED | Engine assembly: cast iron block, crank, rods, pistons, camshaft and lifters, cast iron cylinder head with 7120 casting, valve train, oil pan, valve cover, intake manifold (typical), exhaust manifold (typical). |
| NOT INCLUDED | ECU and harness (sold separately, must be 1996-2001 OBD-II compatible), throttle body, alternator, starter, A/C compressor, power steering pump, water pump, thermostat, flywheel and clutch (manual transmission interface), motor mounts, distributor, complete vehicle (this is engine only). |
| Fluids | Drained before shipping. Refill with 10W-30 motor oil. Regular unleaded 87 octane fuel acceptable. |
| Core Note | No core charge. You are not required to return your old engine. |
Vehicle Compatibility
This 1998-sourced 4.0L engine fits the following vehicles:
| Vehicle | Compatibility |
|---|---|
| Jeep Cherokee XJ (1996 to 2001) | Direct OBD-II fit, exact-year match for 1998 XJ |
| Jeep Wrangler TJ (1997 to 2006) | Cross-fit with appropriate intake manifold orientation |
| Jeep Grand Cherokee ZJ (1996 to 1998) | OBD-II era cross-fit |
| Jeep Grand Cherokee WJ (1999 to 2004) | Cross-fit with appropriate ECU calibration |
Manual-transmission applications particularly benefit from this engine AX-15 donor lineage.
Inspection Workflow
This 1998 XJ 4.0 engine is sourced from a manual-transmission 1998 Cherokee donor and inspected before shipping:
- Visual inspection of block, head, and oil galleries
- Cylinder head casting code documented (7120 era, pre-0331 problematic casting)
- Manual transmission interface (rear of block) inspected for any damage from clutch failure events
- 1998 manual donor authentication via casting numbers and head stamp
- Donor application photographed (1998 XJ manual transmission origin)
This is positioned as a vintage donor variant rather than a fully-documented and compression-tested premium core. For complete inspection paperwork with compression test results across all 6 cylinders, see our Jeep Cherokee 4.0 Engine for Sale at $1,999.
Why Buy From Part Nests
- 1998 XJ manual-donor sourced for original manual-configuration match
- 7120 head casting documented (pre-0331 era, lower crack risk)
- Manual transmission interface specifically inspected
- Visual inspection completed before shipping
- Cross-link to multiple Jeep 4.0 listings for buyers with different needs
- Free freight pallet to all 50 states, no hidden fees
- No core charge, keep your old engine
- 15 day replacement warranty on manufacturing defects
- Call (240) 306-7051 to confirm 1998-vintage donor sourcing, 7120 head casting, AX-15 manual transmission interface, and HO-era ECU compatibility before ordering
15 Day Replacement Warranty
Every 1998 XJ 4.0 manual-donor engine purchased through Part Nests carries a 15 day replacement warranty starting on the delivery date.
What Is Covered
- Manufacturing defects already present when the engine arrives
- Visible damage beyond what was disclosed at shipping
- Cylinder head crack failures not disclosed at shipping (the 7120 casting is significantly less crack-prone than 0331, but inspected and disclosed openly)
- Manual transmission interface (rear of block) damage not disclosed at shipping
- Incorrect donor variant shipped (non-1998-vintage or non-manual-donor engine sent) due to an error on our end
What Is Not Covered
- Damage caused during installation
- Damage from operating with neglected cooling system (the 4.0 is sensitive to cooling system condition; replace thermostat and water pump at install if condition unknown)
- Damage from running with incorrect ECU calibration (this engine is HO-era OBD-II; pre-1996 Renix electrical systems are not compatible)
- Damage from incorrect flywheel or clutch installation (manual donor interface; pilot bearing and clutch alignment critical)
- Damage from extended oil change intervals or incorrect oil viscosity (Jeep-spec 10W-30 recommended)
- Compression performance beyond what is typical for a budget-tier vintage donor unit (for comprehensive compression-tested coverage, see main listing)
- External components (ECU, harness, throttle body, alternator, starter, A/C, P/S, water pump, thermostat, flywheel, clutch, pilot bearing, motor mounts, distributor) unless itemized
- Labor expenses of any kind
To start a warranty claim, reach us within 15 days of delivery at (855) 634-4447.
- 1998 XJ Manual Donor Sourced: AX-15 manual transmission origin match
- 7120 Head Casting: Pre-0331 era, lower long-term crack risk
- HO-Era OBD-II Compliant: Compatible with 1996-2001 XJ, TJ, ZJ chassis
- Manual Transmission Interface Inspected: Rear of block checked for clutch-failure damage
- Cross-Link to Multiple Listings: ($1,999) premium, ($800) automatic donor available
- 15 Day Replacement Cover: Manufacturing defects protected from delivery onward
Additional information
| engine-type | Inline-6 (I6) |
|---|---|
| displacement | 4.0 liters (242 cu in) |
| horsepower | 190 hp at 4, 600 rpm |
| torque | 225 lb-ft at 3, 000 rpm |
| block-material | Cast iron |
| head-material | Cast iron |
| head-casting-code | 7120 era (pre-0331) |
| valve-train | OHV (Overhead Valve, pushrod) |
| fuel-system | Multi-Port Fuel Injection (MPFI) |
| era | HO (High Output), OBD-II compliant |
| donor-year | 1998 |
| donor-model | Jeep Cherokee XJ Classic (manual transmission configuration) |
| donor-transmission | AX-15 5-speed manual |
| drivetrain-donor | 4×4 |
| compatibility | 1996 to 2001 XJ, 1997 to 2006 TJ, 1996 to 1998 ZJ, 1999 to 2004 WJ |
| price | $800.00 |
| Brand | Jeep |
Donor transmission origin, mechanically identical engine. The listing (also $800) is sourced from a 1998 XJ with the AW4 4-speed automatic transmission. This listing is sourced from a 1998 XJ with the AX-15 5-speed manual transmission. The engine itself is the same HO 4.0 with the 7120 head casting, but some buyers specifically want a manual-donor unit because the engine internals may show different wear patterns when paired with manual transmissions, and because manual-transmission XJ enthusiasts prefer the lineage of an engine that came from an AX-15 configuration. Both listings are valid; choose based on your build.
The 5-speed manual transmission used in many Jeep XJ and TJ applications. The AX-15 (also called the Aisin AR5 in some markets) is a 5-speed manual transmission manufactured by Aisin for Jeep, used in 1989 to 1999 Cherokee XJ, 1987 to 1999 Wrangler YJ and TJ, and select Grand Cherokee ZJ applications. It is a robust manual transmission rated for the 4.0L AMC inline-6 torque output. AX-15 transmissions are popular with XJ and TJ enthusiasts because they pair the rugged 4.0 with manual gear selection, which is preferred for technical off-road work where engine braking control matters.
Wear patterns can differ between manual and automatic donors. An engine that spent its life paired with an AX-15 manual transmission saw different RPM and load patterns than the same engine paired with an AW4 automatic. Manual-transmission users typically shift at higher RPM points and apply more aggressive engine braking, which produces different bearing and cylinder wear patterns. In many cases, manual-donor 1998 XJ 4.0 engines come from lower-mileage XJ Cherokees (because the manual XJ Cherokees were typically less popular than the automatic AW4 Cherokees, so manual-donor cores often have fewer accumulated miles).
Yes, but you will need the AW4 flexplate and associated components. The engine itself is mechanically identical between manual and automatic donor configurations. The difference is in the rear of the engine: a manual donor uses a flywheel + clutch + pilot bearing setup, while an automatic donor uses a flexplate + torque converter setup. If you are installing this manual-donor engine in an AW4 automatic chassis, you will need to source the AW4 flexplate, torque converter, and associated transmission interface hardware to match your chassis. The block bolt pattern accommodates both transmission types.
Same fundamental engine, same budget tier. Both (automatic donor) and (manual donor) are positioned as budget-tier 1998 XJ donor cores at $800. The pricing parity reflects that the engines themselves are mechanically identical; only the donor configuration history differs. The premium tier (main multi-year listing at $1,999) has comprehensive compression test paperwork and is independent of donor transmission configuration.
The 1998 XJ uses the earlier 7120 casting. The 0331 cylinder head casting used on 2000 and 2001 model year Jeep 4.0 engines is documented as crack-prone between cylinders 3 and 4. The 1998 XJ donor uses the earlier 7120 casting, which is significantly more reliable. This is one of the meaningful selection criteria for buyers wanting a 1998-vintage donor specifically: the 7120 head casting predates the 0331 problematic casting era. We confirm the 7120 casting on every 1998-donor-sourced engine before shipping.
No. This listing is for the engine only. The page title references "1998 Jeep Cherokee XJ 4.0L Engine" because the engine is sourced from a 1998 XJ manual-transmission donor vehicle. The complete vehicle is not part of this listing. You are buying the 4.0L inline-6 engine assembly (long block plus typical intake and exhaust manifolds) sourced from a 1998 XJ Cherokee that originally had the AX-15 manual transmission.
No. There is no core return required.
2 reviews for 1998 Jeep Cherokee XJ 4.0L Engine | OEM Used Manual Transmission Donor Variant
Related products
Devon C. –
Got the 1998 XJ manual-donor 4.0 for an AX-15 5-speed XJ repower. Manual donor lineage confirmed (AX-15 origin), 7120 head casting documented, HO-era OBD-II compliance verified. Honest pre-purchase information about the difference between this manual-donor variant and the automatic-donor vaz70 listing. Foundation for keeping the manual XJ alive.
Sammie R. –
Sourced this engine for a Wrangler TJ manual swap project. Manual transmission interface inspected clean (no clutch failure damage), 7120 casting confirmed. Cross-link to vaz69 premium listing and vaz70 automatic donor was clearly explained — picked this manual-donor variant because the TJ is also AX-15 equipped.