Hemi, Pentastar & EcoDiesel Problems: Pros and Cons

Stellantis (formerly FCA, and Chrysler before that) built five engines that turn up in almost every used Jeep, Dodge, Ram and Chrysler from the last fifteen years: the 3.0 V6 diesel, the 3.6 Pentastar V6, and three Hemi V8s, the 5.7, the 6.4 (392) and the supercharged 6.2 Hellcat. The Jeep Grand Cherokee WK2 (2011–2021) is the only car that was offered with all five, so it's the easiest way to compare them.

They are very different engines with very different weak points. Choosing the right one matters more than the badge, the trim or the model year.

At a glance

3.0 V6 diesel (EcoDiesel / CRD)

Designed by the Italian VM Motori, this engine is sold as the 3.0 CRD or MultiJet in Europe (Grand Cherokee, Lancia Thema, Chrysler 300C) and as the EcoDiesel in North America (Grand Cherokee, Ram 1500, and later the Wrangler and Gladiator).

Pros

• Around 550–570 Nm of torque, with economy a petrol V8 can't match: roughly 8–10 L/100 km (24–29 mpg US) in a Grand Cherokee.
• The best engine in the range for towing and for long motorway mileage.

Cons

• EGR cooler cracking. The best-known fault, serious enough to trigger recalls on North American EcoDiesels. Coolant loss with no visible leak and white exhaust smoke are the warning signs.
• Emissions hardware. The DPF, the EGR valve and (on later cars) the AdBlue/DEF system all suffer from short trips. In the US, 2014–2016 EcoDiesels were part of an emissions settlement that required a software update, so check that it was done.
• Bottom-end failures. Crankshaft and main-bearing failures have been reported on earlier engines. They're uncommon but expensive, often $8,000+ / €8,000+ for a replacement engine.
• Oil cooler and oil-filter-housing leaks.

Buy it if you do real mileage or tow, and the car has a complete service history with recall and emissions work documented. Avoid it if you mostly drive around town.

3.6 Pentastar V6

Stellantis's highest-volume engine, fitted to the Grand Cherokee, Wrangler, Durango, Charger, Challenger, 300, Pacifica, Voyager and more. It's what most Grand Cherokees on the used market have.

Pros

• Parts are cheap and everywhere, and any mechanic knows it.
• Timing chains rather than a belt, no turbo, and nothing exotic.
• Adequate performance: about 7–8 seconds to 100 km/h in a Grand Cherokee.

Cons

• Oil cooler / filter housing leaks. The plastic housing in the valley of the engine cracks or its gaskets fail, leaking oil (and sometimes coolant). It's very common, and a repair typically costs $500–$1,000 / €500–€1,000, mostly labour.
• Left cylinder head (2011–2013). Early engines suffered valve-seat problems on the left-hand head, usually showing as a misfire on cylinder 2 with a tick. FCA extended the warranty at the time, so check whether a replacement head was fitted.
• Rocker arm and lifter tick. Some engines develop a ticking valvetrain, and replacement is labour-heavy.
• Water pump. It's driven by the timing chain, so replacing it is a bigger job than on most engines.
• Thirsty for its power: about 11–13 L/100 km (18–21 mpg US) in a Grand Cherokee.

Buy it if you want the lowest-risk, cheapest-to-fix option. Prefer 2014 on, after the early head problems were sorted. Budget for the oil cooler housing if it hasn't been done.

5.7 Hemi V8

The classic Hemi, in the Grand Cherokee, Durango, Ram 1500, Charger, Challenger and 300C.

Pros

• A proven, understressed pushrod V8 with a satisfying soundtrack.
• Strong towing (up to about 3,300–3,500 kg in a Grand Cherokee) and a simple layout.
• Parts are cheap and plentiful.

Cons

• Lifter and camshaft failure, the "Hemi tick". The best-known Hemi problem. A lifter roller seizes or wears and then damages the camshaft lobe. It's widely linked to the cylinder-deactivation (MDS) lifters, long idling and stretched oil changes. A camshaft-and-lifters job typically runs $3,000–$6,000 / €3,000–€6,000.
• Broken exhaust manifold bolts. They cause a ticking noise on cold starts that is often confused with the lifter tick. It's cheaper to fix, but still a common find.
• Fuel: about 14–17 L/100 km (14–17 mpg US) in a Grand Cherokee.

Buy it if you want a V8 you can live with. Listen carefully at cold start and ask for oil-change receipts.

6.4 Hemi V8 (392)

The big naturally aspirated Hemi, in the Grand Cherokee SRT (2012–2021), the Durango SRT, and the Charger and Challenger 392 / Scat Pack.

Pros

• About 470–485 hp with no supercharger to maintain, and linear, predictable power.
• In a Grand Cherokee SRT, it came with bigger Brembo brakes and adaptive dampers instead of the air suspension found on regular models.
• Many enthusiasts see it as the best mix of performance and reliability in the Hemi family.

Cons

• Lifter and camshaft wear has been reported on the 6.4 too. It's the same design family and the same concern.
• Running costs: SRT brakes and tyres are expensive, and fuel use is similar to or worse than the 5.7.
• Oil consumption has been reported by some owners. Check the level and ask how often it's topped up.

Buy it if you want serious performance without the Hellcat's costs and risks.

6.2 Supercharged Hellcat V8

The 707 hp engine in the Grand Cherokee Trackhawk, the Durango SRT Hellcat, the Charger and Challenger Hellcat, and the Ram TRX.

Pros

• Enormous, reliable power when stock. The engine itself is tough.
• It shares its basic architecture with the other Hemis, so many service parts are familiar.

Cons

• The driveline takes the punishment: front differentials, transfer cases and driveshafts on AWD cars.
• Supercharger snout bearing wear at higher mileage.
• Tuned cars are everywhere. A smaller pulley or an E85 tune puts every problem on a shorter clock.
• Running costs in tyres, brakes and fuel are in supercar territory.

We covered this one in depth in the Jeep Trackhawk problems guide, including the viewing checks that catch a thrashed car.

The free checks to do at the viewing

These work for all five engines:

1. Insist on a cold start. Put your hand on the bonnet before the seller starts the car. A warm engine hides the lifter tick, manifold-bolt tick and diesel start-up problems.
2. Listen for ticking that doesn't settle. A tick that fades within a minute is often normal injector or valve noise. One that stays, or gets louder with revs, needs a specialist to diagnose before you buy.
3. Look for oil in the V of the engine. On the Pentastar, oil pooling around the oil cooler housing at the back of the V is the tell-tale sign.
4. Check the coolant level on the diesel. A level that keeps dropping with no visible leak points to the EGR cooler.
5. Count the oil changes. Short, regular intervals are the best predictor of a healthy Hemi or diesel. Stretched intervals are the most common reason these engines fail early.
6. Run the VIN. Open recalls, and on diesels the emissions update, should all show as completed.

Which one to buy

• Lowest risk: the 3.6 Pentastar, from 2014 on, with the oil cooler housing already replaced.
• Best V8 to live with: the 5.7 Hemi, with oil-change records and a quiet cold start.
• Best performance for the money: the 6.4 Hemi. It's the enthusiast's pick.
• High mileage and towing: the 3.0 diesel, but only with complete history and no town-only use.
• Only if you know what you're buying: the 6.2 Hellcat. Buy stock, never thrashed.

Run the exact car through the AutoFindr analyzer for its reliability score, the documented failure modes at that mileage and a fair-price band. Budget the years ahead with the maintenance cost estimator, and pull a VIN history check before you pay (AutoFindr readers get 20% off carVertical with code AUTOFINDR). Many V8 models outside North America are imports, so read what US and Canadian title brands mean too.