2018 Jeep Grand Cherokee engine problems

Blown or cracked head gaskets causing coolant leakage into combustion chambers, often diagnosed alongside cracked cylinder heads. Owners report compression loss, misfire codes, and catastrophic engine failure requiring full engine replacement at costs of $8,000–$14,000. The issue occurs at relatively low mileage (40,000–95,000 miles) with no prior warning.

When: 40,000–95,000 miles; some reported under 50,000 miles; one case at 85,599 miles

Symptoms owners cite: Check engine light with misfire codes (P0303, P0304, P0305, P0300); White smoke from exhaust; Rough idle; Loss of power/deceleration; Coolant in oil or oil in coolant; Vehicle stalling; Engine overheating

Codes mentioned: P0303, P0304, P0305, P0300

Repairs/costs cited: Cylinder head replacement, head gasket replacement, engine replacement (full block); costs cited: $8,000–$14,000; parts commonly replaced include timing cover gasket, valve cover gasket, cam sensor gasket, intake gaskets, exhaust gasket, spark plugs, coolant refill

Water pumps fail and leak coolant under normal driving conditions, often described as made of plastic housing that does not hold up to vibration and use. Multiple owners report backorders affecting hundreds of vehicles waiting for replacement parts.

When: 67,670–82,000 miles reported; one case at 67,300 miles with overheating in short distances

Symptoms owners cite: Visible coolant puddles under vehicle; Check engine light; ESC (electronic stability control) warning light; Engine overheating; Inability to drive vehicle

Repairs/costs cited: Water pump replacement; parts on national backorder with hundreds of vehicles in line (one report: #300 in backorder queue); repair shop stated inability to procure parts

Oil housing units made of plastic (rather than aluminum) crack and dump oil from the engine under normal operation. One owner reported engine seizing after oil lamp illuminated due to inability to get service appointment in time; owner lost reliable transportation.

When: 2.5 weeks after purchase; ~1,200 miles on odometer

Symptoms owners cite: Significant oil leakage from engine; Oil warning lamp illumination; Engine seizing

Repairs/costs cited: Oil housing unit replacement (plastic component); owner reported recall exists for this issue; one case involved engine seizure requiring towing and potential engine replacement

Recalls/TSBs owners mention: Recall exists (owner identified after failure)

EGR coolers crack, creating internal coolant and exhaust leakage that escalates to engine compartment fires. One vehicle caught fire at a parking structure with only 300 miles; another ignited with yellow-grayish smoke, flames, and sparks after display of rough running and loss of function. One owner reported same issue recurring after recall repair using replacement part from same batch.

When: 10,000 miles (first failure with stall); 74,000 miles (engine fire); 104,000 miles (fire hazard); repeat failure at 35,000 miles after recall repair

Symptoms owners cite: Yellow-grayish or white smoke from engine compartment; Extreme rough running; Loss of engine power; Flames visible under hood; Liquid and debris underneath vehicle with sparks; Check engine light

Codes mentioned: P0304

Repairs/costs cited: EGR cooler replacement (under NHTSA 20V699000 recall); one owner reported replacement part failed with identical issue 3 years and 35,000 miles after initial repair; parts for recall unavailable as of multiple complaint dates

Recalls/TSBs owners mention: NHTSA Recall 20V699000 (Engine and Engine Cooling); recall repair parts unavailable for extended periods (1+ year reported); second recall 23V411000 for same component

Diesel Grand Cherokee engines experience sudden violent rough running, full engine shutdown, and complete loss of function at highway speeds despite fuel gauge showing adequate fuel. Multiple episodes traced to fuel pressure regulation failure or fuel level indication design fault. Filling with diesel restores function temporarily. One owner noted forums document this issue dating back pre-2008 in diesel Jeep engines.

When: First episode a few months after purchase; second episode one week later; both at highway speeds

Symptoms owners cite: Sudden violent engine running; Engine idling extremely rough; Complete engine shutdown within seconds; Loss of all vehicle function; Fuel gauge reading over 1/4 tank but insufficient fuel condition; Unsafe loss of acceleration

Codes mentioned: Insufficient fuel to engine codes, Fuel rail codes, Fuel pressure codes

Repairs/costs cited: Fuel system top-off with diesel; no permanent repair identified by dealer; OBD codes cleared by dealer

Recalls/TSBs owners mention: Dealer claims no knowledge of similar issues despite owner forum research showing widespread diesel engine problems

Engine lifters or rocker arms fail, causing intake camshaft failure. Results in severe misfires, loss of power, and vehicle becoming completely inoperable. One owner reported Stellantis no longer produces replacement intake camshafts for the engine, parts listed indefinitely back-ordered and unavailable, leaving vehicle permanently disabled.

When: No specific mileage stated; symptom preceded failure (faint ticking noise)

Symptoms owners cite: Faint ticking noise from engine before failure; Sudden severe misfires; Loss of power; Vehicle completely inoperable; No warning lights or dashboard messages before failure

Repairs/costs cited: Rocker arm/lifter and intake camshaft replacement required; intake camshaft no longer manufactured by Stellantis, indefinitely back-ordered, no factory fix available

Recalls/TSBs owners mention: No factory fix; parts unavailable

Cylinder 3 misfire diagnosed with white smoke from exhaust. Dealership replaced coil and all spark plugs, but check engine light remained and white smoke persisted. Further diagnosis indicated entire engine replacement needed due to severe coolant leakage. One case involved an owner waiting 3+ months for engine on national backorder; dealership refused responsibility post-sale.

When: Mileage not specified in narrative; vehicle later required engine replacement

Symptoms owners cite: Check engine light illumination; White smoke from exhaust; Start/stop warning light; Cylinder 3 misfire; Hesitation and stalling (potential); Engine performance degradation (potential)

Codes mentioned: Cylinder 3 misfire code

Repairs/costs cited: Coil 3 and spark plugs replaced initially (ineffective); later diagnosis: severe coolant leakage, full engine replacement required; engine on national backorder (3+ months waiting); dealership and manufacturer declined goodwill assistance

Recalls/TSBs owners mention: None; dealership stated post-sale responsibility declined

Starter fails, often diagnosed alongside water pump leaks and blown head gaskets. One owner reported failed AC compressor causing internal starter failure plus leaking water pump; another noted whitish smoke from exhaust after starter replacement, later requiring head gasket replacement.

When: 10,000–40,000 miles reported for starter failure

Symptoms owners cite: Vehicle fails to start; No warning lights before failure; Whitish smoke from exhaust (when related to head gasket); Multiple system failures occurring concurrently

Repairs/costs cited: Starter replacement; head gasket and water pump replacement may follow; one case: engine replacement required at 40,000 miles with $14,000 labor cost quoted

Metal shavings detected inside engine during diagnostic examination, indicating internal engine wear or damage. Vehicle unable to operate normally and not repaired; manufacturer offered no assistance.

When: 109,000 miles

Symptoms owners cite: Check engine light flashing on and off; Vehicle deceleration

Repairs/costs cited: Vehicle not repaired; dealer found metal shavings during inspection but no repair action documented

Recalls/TSBs owners mention: Manufacturer notified but offered no assistance

High-pressure fuel pump failure in diesel EcoDiesel models. NHTSA Recall Z46 issued June 2022 for this defect, but replacement parts unavailable over one year later, preventing recall completion and making vehicles unsellable with open recall.

When: Not specified; recall issued June 2022

Symptoms owners cite: Fuel pump failure (specific symptoms not detailed in narrative)

Repairs/costs cited: High-pressure fuel pump replacement required per Z46 recall; Bosch-redesigned parts unavailable; dealership advised 'no parts available' repeatedly over 1+ year; one owner unable to sell vehicle due to open recall, suffering economic injury

Recalls/TSBs owners mention: NHTSA Recall Z46 (High-Pressure Fuel Pump, Diesel); parts unavailable; Stellantis customer assistance failed to respond or escalate complaint

Stop/Start system fails to function correctly, causing unexpected engine shutoff during driving and vehicle stalling. One incident occurred at 65 mph on turnpike. Another involved repeated unexpected restarts and RPM anomalies. System logic also fails to prevent leaving engine running when exiting vehicle with key fob separated.

When: 26,000 miles (first stall report); 37,007 miles (multiple stalls); incidents at highway speeds (45–65 mph)

Symptoms owners cite: Engine stalling while driving at highway speeds; Engine will not shut off when owner exits vehicle; Unexpected engine restarts; RPM gauge dropping to 0 then restarting; All dashboard lights coming on as if starting vehicle; 'Pull over, shift to park, and restart vehicle' message displayed; 'Automatic off' error light displayed; Service Start/Stop switch warning light illumination

Repairs/costs cited: Start/Stop switch service required; one case awaiting dealership appointment; another case unresolved as of report date

Coolant leaks into engine, contaminating oil and causing combustion gas presence in cooling system. Diagnosed via stored diagnostic trouble codes showing coolant in combustion chamber. One case involved suspected prior hurricane damage but history unclear due to multi-owner sales.

When: 67,300 miles (overheating at short distances; car purchased post-recall with 2,500 miles)

Symptoms owners cite: Engine overheating in short distances; Check engine light with cylinder misfire codes; Combustion gases in cooling system (diagnostic finding)

Codes mentioned: P0304

Repairs/costs cited: Cylinder head replacement and full engine replacement required; quoted repair cost $8,001.88 (owner unable to pay); dealer also identified as having performed recall work

Engine seizes from prolonged coolant loss due to cracked oil housing unit or similar cooling system failure. Occurs when owner unable to obtain timely service appointment and attempts to maintain oil levels while waiting.

When: ~1,200 miles after purchase; owner could not get service appointment until after New Year

Symptoms owners cite: Oil warning lamp illumination; Coolant loss causing low coolant condition; Engine seizing suddenly

Repairs/costs cited: Engine replacement required; issue traced to cracked coolant and oil housing unit (plastic material); recall identified post-failure

Recalls/TSBs owners mention: Recall exists for oil housing issue (identified by owner post-failure)

Engine shakes or idles roughly, accompanied by misfire codes and low coolant. Diagnosis indicates blown head gaskets from incorrectly machined engine block. Requires short block removal/replacement, cylinder head resurfacing, and head gasket replacement.

When: September 2025 reported; low mileage context suggests early failure

Symptoms owners cite: Vehicle shaking on idle; Losing coolant; Burning coolant in cylinder; Rough idle when starting

Repairs/costs cited: Short block removal and replacement, cylinder head resurfacing, head gasket replacement; owner attributed to manufacturing error in engine machining; total cost $8,000+

Camshaft failure or cam sensor failure diagnosed during vehicle assessment for other issues. One case involved loss of motive power intermittently with burning odor; another involved failed start attempt. Repairs include cam shaft replacement and related gasket work.

When: 100,000 miles (loss of power case); 101,000 miles (startup failure case)

Symptoms owners cite: Loss of motive power (intermittent); Burning odor inside cabin; Check engine light illumination; Vehicle fails to start

Repairs/costs cited: Cam shaft replacement required; one case also required oil valve and unknown parts replacement; repairs not completed as of report date

Vehicle catches fire in engine compartment with minimal warning. One fire occurred at parking structure with only 300 miles on vehicle; another at idle while parked with vehicle in park. Fire department called and vehicle destroyed in both cases.

When: 300 miles (first fire); 74,000 miles (second fire)

Symptoms owners cite: Grayish-white smoke from engine compartment without warning; Flames visible under hood and over windshield; Vehicle destroyed by fire

Repairs/costs cited: Vehicle not repaired (total loss); fire report filed; one case linked to NHTSA Campaign 20V699000 (EGR cooler related)

Recalls/TSBs owners mention: One case: NHTSA Campaign 20V699000 identified; dealer and manufacturer offered no assistance