Hellcat 6.2L Cylinder Head Guide: 2015-2025 Charger, Challenger, RAM 1500 & More
This guide covers failure symptoms, inspection tips for used parts, and key differences for the cylinder heads used in the Dodge Challenger, Charger, Durango, Jeep Grand Cherokee Trackhawk, and Ram 1500 TRX.
- The most common cause and symptom of cylinder head failure is engine overheating. Any sign of overheating should be investigated immediately to prevent head damage.
- When buying a used head, you MUST inspect it for cracks (especially between valve seats) and warpage (with a straightedge and feeler gauge) before installation.
- This standard Hellcat head (part # 68225718AF) is NOT the same as Redeye/Demon heads, which have superior internal components for heat and RPM tolerance. They are physically interchangeable but not functionally identical.
- Cylinder head bolts are torque-to-yield (TTY) and MUST be replaced with new ones. Reusing them will lead to improper sealing and guaranteed failure.
Symptoms of a Failing Cylinder Head
Cylinder head failure on a high-performance engine like the 6.2L Hellcat is a serious issue. The most common cause is extreme heat, which can cause the aluminum head to warp or crack. This compromises the seal between the head and the engine block, leading to a variety of symptoms. Often, the first part to fail is the head gasket, but the underlying cause can be a warped head. Here are the key signs to watch for:
- Engine Overheating: This is the most common symptom and also a primary cause of failure. A crack or warp in the head can allow combustion gases to enter the cooling system (creating air pockets) or coolant to leak, causing the engine to run hot.
- White Smoke from Exhaust: 🎬 Watch: How to identify head gasket leaks and white smoke Thick white smoke with a sweet smell (like maple syrup) from the tailpipe is a classic sign of coolant being burned in the combustion chamber. This happens when a crack or bad head gasket allows coolant to leak into a cylinder.
- Milky, Foamy Engine Oil: If you check your oil dipstick or look under the oil filler cap and see a milky, light-brown substance that looks like a milkshake, it means coolant is mixing with your engine oil. This is a critical symptom, as contaminated oil cannot lubricate the engine properly and can lead to catastrophic failure.
- Unexplained Coolant Loss: If you are constantly adding coolant but see no visible leaks or puddles under the vehicle, it may be leaking internally through a crack in the cylinder head.
- Bubbling in Coolant Reservoir: With the engine running, look for bubbles in the coolant overflow tank. This indicates that high-pressure combustion gases are being forced into the cooling system, which points to a breach between the combustion chamber and a coolant passage.
- Engine Misfires and Rough Idle: Coolant leaking into a cylinder can foul the spark plug, preventing proper ignition. This will cause a noticeable engine misfire, which you might feel as a rough idle, stumbling, or hesitation during acceleration. This may also trigger the Check Engine Light with codes like P0300 (Random/Multiple Cylinder Misfire) or a cylinder-specific code like P0301-P0308.
- Loss of Power: A crack in the head or a failed head gasket can cause a loss of compression in one or more cylinders, resulting in a significant drop in engine power.
Warning: Do not continue to drive a vehicle with a suspected cracked cylinder head. Driving with coolant in the oil or with a severe overheating condition can quickly lead to complete engine seizure and catastrophic, irreparable damage.
Known Issues, Recalls, and Technical Service Bulletins (TSBs)
While the 6.2L Hellcat engine is generally robust, no specific recalls or widespread TSBs directly address a high rate of cylinder head failure on the listed vehicles. Most issues are isolated incidents, often stemming from overheating or extreme use. Some early owner reports on forums for the RAM 1500 TRX mentioned misfires that were sometimes traced back to head gasket issues, which are directly related to the cylinder head's sealing ability. However, these do not appear to represent a systemic defect.
Standard Hellcat vs. Redeye/Demon Heads
🎬 See a detailed comparison of Hellcat and Redeye engine componentsA critical point for buyers is the difference between standard Hellcat heads and those found on higher-output models like the Redeye, Demon, and Super Stock.
- Standard Hellcat Head (Part # 68225718AF and its predecessors): This is the head specified for the vehicles in this guide.
- Redeye/Demon Head (Part # starts with 53010852 or 77072534AB): These heads are physically interchangeable but contain significant internal upgrades. They feature sodium-filled exhaust valves and stronger valve springs and retainers to better withstand the higher RPM limits and increased heat of those models.
Compatibility Warning: You can install a standard Hellcat head on a Redeye engine, but it will de-rate the engine's capabilities. It will not have the same thermal resistance or be able to handle the higher RPMs, compromising performance and long-term reliability under stress. Conversely, upgrading a standard Hellcat with Redeye heads is a common performance modification.
Buying a Used Engine Cylinder Head
A recycled OEM cylinder head can be an excellent value, but careful inspection is absolutely essential. A used head with a hidden crack or severe warp is useless. Here’s what to check before you buy:
- Check for Cracks: This is the most important step. The most common place for cracks to form is in the thin areas of metal between the intake and exhaust valve seats. Also inspect carefully around the spark plug hole. A professional machine shop may use dye penetrant or pressure testing to find hairline cracks invisible to the naked eye.
- Inspect for Warping: 🎬 Watch: How to check cylinder head flatness with a straightedge An overheated head will warp, preventing it from sealing against the engine block. Place a certified straightedge across the flat mating surface of the head. Try to slide a feeler gauge underneath it. Check lengthwise, widthwise, and diagonally. Most manufacturers specify a maximum warp of around 0.003 to 0.004 inches. If a feeler gauge of that thickness can fit under the straightedge, the head is too warped and must be resurfaced by a machine shop before use.
- Examine the Mating Surface: Look for deep scratches, corrosion, or pitting on the flat surface. Run your fingernail across the surface; if it catches in a scratch, it may be too deep to seal properly without machining.
- Inspect Valves and Guides: Look at the valve seats (the rings the valves seal against) for pitting or damage. Wiggle the valves in their guides; excessive side-to-side play indicates wear.
- Verify Part Numbers: Double-check the casting number on the head to confirm you have the correct part for your engine (e.g., standard Hellcat vs. Redeye). The latest part number for the standard right-side head is 68225718AF.
Pro Tip: When purchasing a used cylinder head, ask the seller if it has been pressure tested and checked for flatness. A reputable recycler will often perform these checks. It's often worth paying a small premium for a head that has been verified by a machine shop.
Cost to Replace a Hellcat Cylinder Head
This is a labor-intensive job due to the need to remove the supercharger, fuel system, intake, and numerous other components. Labor costs will be a significant part of the total bill.
| Part Type | Estimated Cost | Notes |
|---|---|---|
| New OEM (Mopar 68225718AF) | $480 - $600 + Core | Price from online Mopar dealers. A core charge of around $150 is typical. |
| New Aftermarket | Not Widely Available | High-performance aftermarket heads exist, but standard-replacement aftermarket options are uncommon. |
| Used OEM (Recycled) | $600 - $1,200 (for a pair) | Price varies greatly based on condition, mileage, and whether sold as a single head or a pair. |
| Remanufactured | $800 - $1,600 (for a pair) | A used head that has been professionally cleaned, inspected, resurfaced, and potentially had valves serviced. |
| Shop Labor | $1300 - $2000 | Estimated 8-10 hours of labor. Varies by shop rate and specific vehicle (e.g., access in a Ram TRX vs. a Challenger). |
Frequently Asked Questions (FAQ)
Can I just replace the head gasket instead of the whole cylinder head?
You can, but if the underlying cause of the head gasket failure was an overheated and warped cylinder head, the new gasket will fail again very quickly. The head MUST be checked for flatness and resurfaced or replaced if it is out of spec.
Is this the left or right cylinder head?
This guide and the part numbers listed (e.g., 68225718AF) are for the RIGHT (passenger side) cylinder head. The left (driver side) head is a different part number.
Do I need to replace the head bolts?
Yes. The head bolts on the 6.2L Hellcat engine are torque-to-yield (TTY) bolts. This means they are designed to permanently stretch when tightened. They are single-use only and MUST be replaced. Reusing old bolts will result in an improper seal and likely lead to head gasket failure.
Is cylinder head replacement a DIY job?
For most people, no. This is a very advanced and complex repair (Difficulty 5/5). It requires a complete teardown of the top half of the engine, specialized tools like torque wrenches and an engine hoist, and a precise, multi-step procedure for torquing the new head bolts. Mistakes can easily lead to catastrophic engine damage. This job is best left to experienced technicians.
Helpful Videos
Technical Specifications
OEM Part Numbers: 68225718AB 68225718AC 68225718AD 68225718AE 68225718AF 53010852AE
Fits right (passenger) side of 6.2L Supercharged HEMI V8. Aluminum construction. Standard Hellcat version, not for Redeye/Demon models which use different internal components.
The information in this article is provided for general reference and educational purposes only. Vehicle specifications, procedures, and part compatibility can vary by production date, trim level, and region. Always consult your vehicle's factory service manual and verify part numbers before purchasing or performing repairs. Safety-critical components such as airbags, seat belts, and braking systems should be installed by a qualified professional.
- Dodge Durango:
- Jeep Grand Cherokee:
- RAM 1500:
- Dodge Challenger:
- Dodge Charger: