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Top issues
17 known problems · 3 high
high
Oil-cooler seal leak ('black death')
3.0L CRD turbo-diesel V6 (OM642)
high
Swirl-flap carbon binding / flap ingestion
3.0L CRD turbo-diesel V6 (OM642)
high
MDS lifter / camshaft tick
5.7L HEMI V8 petrol (EZB)
At this odometer
See which of this car's known problems are due at that mileage, which should already have been dealt with, and what's coming up.
Generations
Best and worst years for the Jeep Grand Cherokee →
Before: Grand Cherokee WJ (1999-2004)
Price (AUD)
$5k-$18k
Body styles
5-door wagon
Drivetrain
Quadra-Trac II full-time 4WD (single-speed/dual-range transfer case), Quadra-Drive II full-time 4WD with electronic limited-slip diffs (dual-range), Quadra-Trac I full-time 4WD (3.7 V6, single-speed, no low range)
Origin
USA
Built in
USA (Jefferson North Assembly, Detroit)
Overview
Known as the WH in Australia (WK in North America), this third-generation Grand Cherokee was sold here as Laredo, Limited and the V8 Overland, plus the off-road-focused 5.7 SRT-adjacent grades. It moved to a fully independent front and rear suspension (a first for the Grand Cherokee) which sharpened the on-road manners at the cost of some extreme-articulation ability versus a live-axle rival. Four engines reached Australia: the 3.7L PowerTech V6 petrol (base), the 4.7L PowerTech V8 petrol, the 5.7L HEMI V8 petrol and the much-loved-but-fragile 3.0L CRD turbo-diesel V6 (the Mercedes OM642). The diesel and the petrol V8s drive through Mercedes' five-speed W5A580/NAG1 auto; the 4.7 used Chrysler's 545RFE. The big draw is enormous value and a genuine dual-range, full-time 4WD system (Quadra-Trac II / Quadra-Drive II) for very little money. The catch is patchy reliability and a thin, expensive dealer/parts network in Australia - the OM642 diesel in particular suffers oil-cooler 'black death' leaks, swirl-flap and EGR problems, while the HEMI/4.7 are thirsty and have their own exhaust-manifold and lifter foibles. Buy on documented service history, not on price alone. Classed here as a warn-tier 4WD: capable and cheap, but the running costs and out-of-warranty repair bills catch out unprepared buyers.
Engines & variants
3.0L CRD turbo-diesel V6 (OM642)
Engine
3.0L Mercedes-Benz common-rail turbo-diesel V6, DOHC, VGT, EGR
Engine code
Config
V6 turbo-diesel
Displacement
2987cc
Power
160kW @ 3800rpm
Torque
510Nm @ 1600-2800rpm
Drivetrain
Quadra-Trac II / Quadra-Drive II full-time 4WD (dual-range)
Economy
9-11 L/100km combined (real-world 11-13)
Tow (braked)
3500kg
Tow (unbraked)
750kg
Transmission
5AT (Mercedes W5A580 / NAG1)
Timing chain / belt / gear
Chain-driven (no scheduled belt)
Pros
- Strong 510Nm makes it the best tourer/tow engine of the range
- Smooth, refined Mercedes-sourced V6 with good economy for the size
- Far better real-world range than the thirsty petrol V8s
- Genuine dual-range full-time 4WD for very little money
- Mercedes W5A580 auto is robust when fluid is serviced
Cons
- OM642 oil-cooler 'black death' seal leaks are near-universal at age/km
- Swirl-flap and EGR carbon problems can destroy the engine if a flap ingests
- Expensive, labour-intensive repairs and a thin AU diesel-specialist network
- Turbo VGT vanes stick from soot; throttle/limp-mode faults common
- Diesel deleted mid-2008, so good examples are scarce and aging
Known problems
high
Oil-cooler seal leak ('black death')
The OM642's oil cooler sits in the engine valley and its seals harden from heat, leaking oil down the back of the block and into the valley - the infamous 'black death'. Pre-2010 (orange) seals are worst; it presents as low-oil warnings, oil stains and a persistent leak that's hard to trace.
Fix: Replace the oil-cooler seals with the updated Viton (purple) seals; an 8-10 hour job as the turbo and intake must come off. Do swirl-flaps/EGR at the same time to save labour.
high
Swirl-flap carbon binding / flap ingestion
EGR soot and oil vapour build thick tar on the intake swirl-flap shafts. The plastic linkage binds and snaps; in rare cases a flap breaks free, enters a cylinder and bends valves or scores a piston, ending the engine.
Fix: Clean or delete the swirl flaps (swirl-flap delete kit), clean the intake and EGR. Inspect early - this is the failure that turns a cheap Jeep into a write-off.
medium
Turbo VGT actuator sticking / limp mode
Carbon causes the variable-geometry turbo vanes/actuator to stick, giving over- or under-boost, lost power and an electronic-throttle/limp warning that owners often mistake for transmission faults.
Fix: Clean or replace the VGT/turbo, service the EGR and intake; verify boost control with a scan tool before buying.
medium
EGR cooler and intake soot
Heavy EGR soot clogs the intake and cooler, contributing to swirl-flap binding and rough running.
Fix: Intake and EGR clean; some owners fit EGR management where legal.
5.7L HEMI V8 petrol (EZB)
Engine
5.7L OHV HEMI V8 with MDS cylinder deactivation (VCT added 2009)
Engine code
EZB
Config
V8 NA (OHV, MDS)
Displacement
5654cc
Power
240kW (250kW from 2009 with VCT)
Torque
500Nm (520Nm from 2009)
Drivetrain
Quadra-Drive II full-time 4WD (dual-range)
Economy
15-20 L/100km real world
Tow (braked)
3500kg
Tow (unbraked)
750kg
Transmission
5AT (Mercedes W5A580 / NAG1)
Timing chain / belt / gear
Chain-driven
Pros
- Effortless V8 performance and a great tow engine
- Strong, characterful HEMI soundtrack
- Quadra-Drive II with e-diffs is genuinely capable off-road
- Chain-driven - no belt service
- Cheap to buy because petrol thirst scares buyers off
Cons
- Very thirsty, especially around town and towing
- MDS cylinder deactivation linked to lifter/cam tick at higher km
- Exhaust-manifold bolts shear and manifolds tick on a cold start
- Mercedes NAG1 auto needs fluid services or it gets harsh
- Expensive AU running costs offset the cheap purchase price
Known problems
high
MDS lifter / camshaft tick
The Multi-Displacement System lifters can collapse and a cam lobe can wipe, especially on engines that idle a lot or have skipped oil changes, giving a rhythmic tick and misfire under load.
Fix: Replace failed lifters and the camshaft; many owners delete MDS and fit standard lifters with the engine apart. Strict oil-change discipline reduces risk.
medium
Exhaust-manifold bolt failure / tick
Heat cycling shears the exhaust-manifold bolts, producing a cold-start 'HEMI tick' that quietens when warm, plus an exhaust leak.
Fix: Extract broken studs and refit the manifolds with upgraded bolts; weld or replace cracked manifolds.
medium
NAG1 auto harsh shift / valve-body wear
The Mercedes W5A580/NAG1 develops harsh or slipping shifts from worn solenoids/valve body and from leaks at the 13-pin electrical connector that can ruin the TCM.
Fix: Service the fluid on schedule, replace the connector seal, rebuild valve body/solenoids if shifting is poor.
4.7L PowerTech V8 petrol
Engine
4.7L SOHC V8 (high-output from 2008), chain-driven
Config
V8 NA
Displacement
4701cc
Power
170kW (an HO version ~227kW from 2008)
Torque
410Nm (453Nm HO)
Drivetrain
Quadra-Trac II full-time 4WD (dual-range)
Economy
14-18 L/100km real world
Tow (braked)
3500kg
Tow (unbraked)
750kg
Transmission
5AT (Chrysler 545RFE)
Timing chain / belt / gear
Chain-driven
Pros
- Smooth, no MDS deactivation complexity of the HEMI
- Cheaper to buy than the HEMI or diesel
- Chain-driven, no belt service
- Chrysler 545RFE auto is reasonably tough when serviced
Cons
- Underwhelming torque versus the HEMI and diesel for towing
- Still thirsty for the modest performance
- Exhaust-manifold gasket leaks common
- Less desirable, so weaker resale than HEMI or CRD
Known problems
medium
Exhaust-manifold gasket leak / tick
The 4.7's exhaust-manifold gaskets and bolts fail with heat cycling, giving an exhaust leak and a ticking noise.
Fix: Replace manifold gaskets and any sheared bolts; check manifolds for warping.
medium
Cooling system / valve-seat issues at high km
The PowerTech 4.7 can suffer overheating-related head/valve-seat problems if the cooling system is neglected or the engine is run hot.
Fix: Keep the cooling system fresh; investigate any overheating immediately to avoid head damage.
low
545RFE transmission wear
The Chrysler 545RFE can develop harsh shifts or solenoid faults at high km if fluid is never changed.
Fix: Regular fluid and filter service; valve-body or solenoid pack repair as needed.
3.7L PowerTech V6 petrol
Engine
3.7L SOHC V6 (essentially the 4.7 V8 minus two cylinders)
Engine code
PowerTech 3.7
Config
V6 NA
Displacement
3701cc
Power
157kW @ 5200rpm
Torque
315Nm @ 4000rpm
Drivetrain
Quadra-Trac I / Quadra-Trac II full-time 4WD
Economy
13-16 L/100km real world
Tow (braked)
2950kg
Tow (unbraked)
750kg
Transmission
5AT (Mercedes W5A580 / NAG1)
Timing chain / belt / gear
Chain-driven
Pros
- Cheapest way into a Grand Cherokee
- Simpler than the V8s, no MDS
- Chain-driven, no belt service
Cons
- Underpowered for a heavy 4WD - sluggish loaded or towing
- Still drinks fuel for the modest output
- Base Quadra-Trac I lacks a true low range on some cars
- Least desirable engine - lowest resale
Known problems
low
Underpowered / strained drivetrain
Not a fault, but the 3.7 is working hard in a ~2.1t SUV; expect heavy fuel use and poor towing performance, which stresses the auto.
Fix: Buy the V8 or diesel if you tow; otherwise keep loads light and service the transmission.
medium
Exhaust-manifold leak
Like the related 4.7, the 3.7 develops exhaust-manifold gasket/bolt leaks with heat cycling.
Fix: Replace gaskets and sheared bolts.