The Four Most Common 6.4 HEMI Engine Issues. In 2005, the Chrysler 6.4 Hemi debuted with 525 horsepower and 510 torque. This is the crate engine known as the 392 HEMI. Chrysler didn’t start selling cars with the 6.4L V8 Hemi engine until 2011. Power output for factory cars is slightly lower than for crate engines. It is, nevertheless, still a potent performance engine. The 6.4L Hemi engine is also quite powerful and dependable. However, no engine is perfect, and this is no exception. In this tutorial, we’ll go over some of the most prevalent 6.4 Hemi engine issues, as well as some general comments on reliability.
*The 6.4 HEMI may also be referred to as the 6.4L HEMI, 392 Apache, 392 HEMI, FCA 6.4 HEMI, Dodge, Jeep, Chrysler, or Ram 6.4 HEMI. Everything is referring to the same engine.
392 HEMI Background Information
The 6.4 HEMI is also known as the 392 HEMI and the 392 Apache. The 392 refers to the engine’s cubic inch capacity, while Apache is the codename for the 6.4L Hemi engine. One thing to keep in mind is that the 392 HEMI crate engine shares very few parts with the 6.4 Hemi found in factory vehicles. It’s strange because they have the same names and displacement. The crate engine, on the other hand, is a little stronger and more performance-oriented.
That’s not to say the factory 6.4 isn’t capable. In 2011, SRT8 vehicles received the first 6.4L HEMI engine with 470 horsepower and 470 torque. The output was boosted to 485 horsepower and 475 torque in 2015. The engine in the Ram 2500 and 3500 is a lesser power variation. This was due to the necessity for improved fuel economy and a more powerful powerband for towing.
What Vehicles Make Use of the 6.4L HEMI?
The 392 HEMI is found in the following Dodge, Jeep, Chrysler, and Ram vehicles:
- SRT 8 Dodge Charger, SRT 392, R/T Scat Pack
- Dodge Challenger SRT8, Dodge Challenger SRT392, R/T Scat Pack
- SRT Chrysler 300
- SRT Jeep Grand Cherokee
- SRT Dodge Durango
- Ram 2500
- Ram 3500
Certain vehicles, such as the Ram 2500 and 3500, come with various engine options. The 6.4 HEMI V8 is still available for all of the following models. Ram pickups, once again, get a slightly lower output model that’s better suited to efficiency and hauling.
Some of the difficulties discussed in this essay may have a greater impact on particular automobiles than others. Much is likely to depend on how each Dodge, Jeep, Chrysler, or Ram uses the 6.4L HEMI.
The 4 Most Common 6.4 HEMI Issues
Among the most prevalent issues with the Chrysler, Dodge, and Ram 392 Apache engine are:
- MDS (Multi-Displacement System)
- Tick of the Engine
- Failure of Transmission
We’ll return to this topic at the end of the post, but we’d like to explain it now. The 392 HEMI engine is a dependable powerplant. We’re categorizing the issues as a handful of the most frequent. That is not to imply that any of these issues affect a high proportion of 6.4 HEMI engines. Other failures can and do occur on occasion, so this is by no means an exhaustive list.
So, let’s get started and go over each of the issues listed above one by one. We’ll bring everything full circle at the end of the post with some opinions on Chrysler 6.4L reliability.
If you’d rather watch a video, check out our 6.4 HEMI (392 HEMI) Common Problems video below:
1) 392 Faults in the HEMI Multi-Displacement System
The multi-displacement system (MDS) is an exciting new technology. The 6.4 HEMI can shut down four of the eight cylinders when cruising. It’s an excellent approach to utilize a larger engine to provide greater power while being efficient in low-power circumstances. It is, however, a relatively new technology. Solenoid failures appear to be the biggest concern with the 392 HEMI MDS. Some people say the 6.4 V8 MDS is a tad clumsy at times. Fortunately, the mechanism can be turned off manually, ensuring that all eight cylinders are constantly firing.
In general, there are a few long-term problems concerning multi-displacement systems. For one thing, the 392 Apache MDS always turns off the same four cylinders. Why may this be a problem? The combustion process, on the other hand, generates a lot of heat. Some of the heat is beneficial. If the 6.4 HEMI turns off four cylinders for a lengthy period of time, those cylinders may run cooler. When the cylinders are turned off, all reciprocating parts continue to move. Allowing them to run cooler may result in long-term lubrication concerns.
There’s more to it, but we’ll avoid writing hundreds of words and being too technical. The point is that MDS is a promising technology, but it has a few minor flaws, such as solenoid failures. It’s also too early to tell how the 6.4 HEMI MDS will affect engine reliability and longevity.
6.4L HEMI MDS Problems Are Unknown
On the 392 HEMI engine, MDS solenoid problems can and do occur. The long-term impacts of multi-displacement systems, however, remain unknown. Shutting down the same four cylinders for an extended amount of time can be detrimental. When spark plugs run too cold and are unexpectedly called back into service, they might foul quickly. On colder cylinders, oiling may be an issue. The 6.4 HEMI’s cylinders may wear unevenly over time. The list is endless. It’s all conjecture, but basic engineering principles suggest that MDS could have a negative impact on lifetime.
If you’re looking for more information and problems with the multi-displacement system, don’t miss our 5.7 & 6.4 HEMI MDS tutorial.
2) 6.4 HEMI Engine Ticking Issues
Engine ticking on the 392 HEMI could be related to a few of the other typical issues discussed in this article. In particular, the preceding MDS discussion. The FCA 6.4 HEMI engine ticking is an intriguing topic. Some believe that ticking is normal and has no effect on longevity, dependability, or performance. However, several engine ticks have resulted in the 6.4L HEMI engine being completely replaced. Among the most common reasons of 6.4 HEMI engine tick are:
- Lifters who make mistakes
- Lifter rollers that have seized
A few more small issues could cause the Dodge 392 HEMI V8 to tick. However, our primary attention is on the two points listed above. This is also a regular problem with the 5.7 HEMI. Lifter or lifter roller issues may be caused in part by the multi-displacement system. It may not be the only reason, but it makes sense. Lifter difficulties on the 6.4 HEMI are most commonly caused by insufficient oil flow across the lifter rollers, causing them to seize. When this happens, the lifter makes contact with the cam lobes, resulting in an audible engine ticking noise.
Metal-on-metal contact, of course, results in metal shavings entering the engine oil. If the 392 HEMI lifter problems are detected quickly, the oil filter will usually catch the most of this metal. If left for too long, more engine damage may occur.
Symptoms of 392 HEMI Lifter Roller
Look for the following indicators of a problem with the 6.4 HEMI lifter rollers:
- Engine light on
Problems with the 6.4 HEMI lifters can be difficult to identify. It is frequently just the ticking sound with no other symptoms. This makes it even more difficult because some appear to detect 392 Apache ticking without any apparent problems. Misfires or a check engine light may appear in some circumstances, usually as the condition worsens.
The unlucky few who experience lifter roller failures often do so between 80,000 and 120,000 miles. The video below is largely about the 5.7 HEMI, but it’s also a fantastic resource for further information on FCA 6.4 ticking and lifter rollers.
Lifter Roller Replacement for HEMI 6.4L
If found soon, additional engine damage is unlikely. However, the engine will need to be opened up at the very least to replace the camshaft. Parts and labor for 6.4 HEMI cam replacement can easily exceed $2,000.00. Add some extra in case metal shavings destroy other parts, such as the oil pump. Parts and labor costs may exceed the cost of a new remanufactured engine. As a result, some people replace the complete 392 HEMI engine.
Failures in FCA 392 HEMI Transmission
We’ll move through transmission and misfire issues on the 6.4 HEMI at a faster pace. Some of the 392 HEMI engines are coupled to various gearboxes. This, of course, varies depending on whether you’re talking about Dodge Chargers or Ram 3500s. The majority of the issues appear to be with Ram 2500 or Ram 3500 pickups. It may also be unfair to classify these transmission failures as among the most common problems.
It’s safe to suppose that many Ram 2500 and 3500 trucks are subjected to difficult conditions when pulling hefty cargo. This can put a lot of strain on a transmission, causing it to wear out and fail prematurely. Transmission issues can and can occur on Dodge, Chrysler, and Jeep models on occasion.
Again, the failure rate is extremely low. It is, nonetheless, worth mentioning because it might be a costly problem.
6.4L HEMI Transmission Troubleshooting
Among the signs of transmission failure on the 392 HEMI are:
- Clunking noises
- Gears that have gone missing
- Uneven shifts
There are a few other symptoms that could occur. However, slippage, clunking, missing gears, or shifting too quickly may suggest an issue with the transmission. Depending on the severity of the problems, the FCA 6.4L Hemi V8 may require a new transmission.
392 HEMI Transmission Repair
A transmission overhaul or replacement may be necessary. In any case, replacing the 6.4 transmission can cost thousands of dollars. It’s not a problem we’d be too concerned about. Transmission breakdowns affect just a small percentage of automobiles.
4) Misfire Issues with the 6.4 HEMI Engine
Misfires could be caused by lifter roller or MDS solenoid faults. It’s also not quite fair to consider 392 HEMI misfires to be a genuine issue. Misfires are frequently caused by normal wear and tear materials such as spark plugs and ignition coils. That, or misfires are only an indication of a larger issue. Anyway, we’re primarily concerned with spark plugs here.
The 6.4 HEMI engine has 16 spark plugs. Yes, the 392 HEMI use two spark plugs per cylinder. There are also the normal eight ignition coils. There are numerous ignition components that might cause engine misfires. Spark plugs are a wear-and-tear component that should be replaced every 60,000 to 80,000 miles. Ignition coils usually last twice as long.
On the 6.4 HEMI, premature failures are uncommon. However, it is possible, particularly with 16 spark plugs. Nonetheless, these are usually minor repairs. Spark plugs and ignition coils should not be overlooked.
Symptoms of 392 HEMI Misfire
Misfire symptoms on the Dodge, Ram, Chrysler, and Jeep 6.4 HEMI include:
- Codes for faults
- Idle time
- Inadequate performance
A misfire will almost certainly result in a fault code. You may also notice that the 392 HEMI is stuttering, idling poorly, or lacking power. Most people will not notice the power loss because the engine will continue to run normally on the remaining 7 cylinders.
6.4 HEMI Coil and Plug Replacement
Spark plugs are another example of regular wear and tear on the 392 HEMI. Every 60,000 to 80,000 miles, a replacement is expected. Those that abuse their 6.4 HEMIs may require repairs sooner. A set of 16 spark plugs costs between $100 and $150. It’s also a really basic DIY that most people can complete in their driveway. Ignition coils are a little more expensive, but they normally last roughly twice as long as the 6.4 spark plugs.
Reliability of the Chrysler, Dodge, Jeep, and Ram 6.4 HEMI
How trustworthy is the 392 HEMI? Overall, the FCA 6.4 HEMI is a strong and dependable engine. It is not the most reliable engine in the world, but it is significantly superior to the worst. We’ll award the 392 HEMI above-average dependability ratings. For than a decade, it has powered several flagship Dodge, Jeep, Chrysler, and Ram cars. The Apache HEMI 392 engine is a fun, powerful workhorse that has stood the test of time. While some of the typical issues listed can be rather costly, they only affect a small percentage of engines.
However, a large part of 6.4 HEMI dependability and longevity is determined by maintenance. It’s one of the things we can influence. Make sure you’re using high-quality oils and replacing them on a regular basis. If and when difficulties arise, resolve them as soon as feasible. Most 392 HEMI engines will last well past 200,000 miles if properly maintained.
6.4 Summary of HEMI Common Issues
The 6.4 HEMI began life as a crate engine known as the 392 HEMI. FCA began employing the 392 Apache in production cars in 2011, starting with the Dodge Challenger SRT8. Since then, the engine has made its way into various high-performance vehicles and trucks. It’s a strong engine with reasonable performance and dependability. However, no engine is flawless.
MDS solenoids, lifter rollers, transmissions, and engine misfires are some of the most prevalent issues on the 6.4 HEMI. Some of the problems are possible side effects of the 392 HEMI MDS system. This can, however, be turned off manually. While some of the 392 HEMI issues can be costly, they only affect a small percentage of engines.
Overall, the FCA 6.4 HEMI is a fantastic engine. Maintain it well and address any concerns that arise in a timely manner. Otherwise, the 392 HEMI should last well over 200,000 miles in most circumstances.