6.4 Hemi Problems: 7 Possible Solutions of Problems fixed

Ram 6.4 Hemi Problems & How to Fix Them

Nothing is perfect in this world. Especially man-made things. Our beloved RAM 6.4 Hemi is no exception to this obvious rule. 6.4L Hemi is one of the most dependable engines out there if you consider longevity. This engine offers some amazing numbers to impress you at the first glance. 

ram 2500 6.4 hemi problems

But we all know if we can’t take good care of the product, it is really hard to get to those numbers. In this way or due to some other factors you may run into various engine problems. In this article, we are going to offer you the solutions along with showing the symptoms. 

And not only that. This article is a unique piece around the web as it includes almost every topic regarding 6.4 Hemi. Starting from the problems, you will get an overall idea about this engine’s features, you will get the answers to the most frequently asked questions in this regard on the web, and what not! Stay touched!

7 Most Common 6.4 Hemi Problems: Symptoms of misfires on the Dodge, Ram, Chrysler, Jeep 6.4 HEMI include-

1. 392 Hemi Multi-Displacement System Faults

  • The gas engine struggles with towing up steep hills
  • Poor gas mileage while towing
  • High transmission temps climbing steep hills/towing

2. FCA 392 Hemi transmission failure (FCA 392 is just another name of the 6.4 Hemi)

3. 6.4 HEMI Engine Tick Problems

4. Exhaust Leak 

5. PCM Problem 

6. Truck stalls 

7. Problem picking a gear

As we have mentioned earlier, to get the maximum out of something, you have to take utmost care of the product. Sometimes, even with that much care, your product may run into problems. Well, in that case, you had done your part right. But you can’t control some other factors. 

Even with the numbers and great reviews of 6.4 Hemi, sometimes you may get frustrated with the Dodge Ram 6.4 hemi problems. However, the bright side is, if you can find out what is really going on with the engine by taking these problems or symptoms into account, you can save the engine from some possible threats.

6.4 HEMI Common Problems Summary 

Starting with the Multi-displacement system faults (which you never want that to happen), exhaust leaks, and error codes are some of the annoying problems of 6.4 Hemi. For instance, if the MDS starts to throw codes frequently, it indicates that the engine is not in a good shape. 

A transmission failure and the ticking problem may irritate you even more. We know how it feels to listen to a constant annoying-ticking sound. And if the engine starts to make the truck stall, you will get another reason to be worried. 

And facing problems while picking a gear along with the bogging down problem of the engine. If you have a good understanding of these symptoms of the engines, it may give you an edge. Because if you manage to take these problems into account, chances are you are going to be in a very economic position. 

6.4 HEMI Engine Failures Common Problems 

We already know how a problematic 6.4 Hemi would react. It is time to break down the symptoms to give you a better and transparent visual regarding the problems. Thus you will be able to counter some possible big threats. 

1. Ram 6.4 hemi transmission problems

The transmission problem is one of the most common problems a 6.4 Hemi faces. And you will be surprised to hear how dangerous a problematic transmission is for your vehicle. Even though the replacement cost of transmission may be more than the engine, you should not waste a moment to do so. Otherwise, you will face some serious issues with your vehicle. 

Generally, a good transmission runs smoothly without any hassle. Shifting gears will give you a smooth feeling and you won’t hear any noise while driving down the road. 

If you face any issues with these two, you have to confirm that it is a transmission-related issue. Because if you can find out the problem at an early age, you may not need to replace the transmission altogether. In that case, replacing the fluid will be enough the resolve the issue. 

Anyway, to confirm any transmission-related issue, you have to check the fluid level. If you find out a low fluid level, it means there is a leak. Along with this, check the fluid color at the same time to determine any problem in the fluid. If the color looks red or pink, it indicates that the transmission fluid is okay. 

If the fluid is okay, there is something wrong with the transmission and vice versa. 

2. Tick-sound problem

Hemi 6.4 is not alone in this particular issue. Many of the previous generation engines had also faced a similar issue and experts say that it passed to Hemi 6.4 from them. It is a confusing matter as this ticking sound may be caused due to many reasons. That is why it is really hard to find out the exact reason behind the sound. 

You have to do some troubleshooting to discover the culprit behind the sound. Sometimes the sound may start during the starting of the vehicle and goes away after a little while. This won’t be a serious issue for you. 

The sound may also emerge if you have a lifter failure. In that case, you have to take immediate action to address this issue as it not only replicates the sound but also harms the camshaft. It will be really bad, won’t it? 

And here is a pro tip from us. Take your camera or turn on your phone’s camera. Create a video when the sound starts to replicate. It will help you when the mechanics will give your vehicle a hand. Because, not always the sound will replicate the same way. 

3. Multi-Displacement System Faults

Multi-Displacement System (MDS) is a great technology to have in an engine. First things first, what’s the job of this technology? This technology will shut down 4 cylinders among the 8 of the engine when heavy power is not necessary. Sounds great, right?

As this technology is comparatively new, it is not fully functional. You may get into trouble if it does not work properly. For instance, what if you are going for heavy towing and the MDS is still functioning? That will be a pretty big reason of concern.

The key reason behind this issue is solenoid failures. The technology may sound great to have an economical time with the engine as it saves energy while the engine is functioning. But there is more to this. This technology will shut down the exact same four cylinders every time.

Thus it creates another problem. Well, it won’t seem that much in a short time. But in the long run, you will feel the difference. As four of the cylinders remain inactive for a long period of time, when necessary they may not function well enough. And in that time you will feel the problem truly as the engine won’t be at its peak in terms of performance. 

4. Damaged PCM

Another common problem of the Hemi 6.4 is the rough idling. In some cases, the car even dies in the process. It is really concerning as this problem will make you suffer very much. For this reason, you have to take care of it as soon as you find out the symptoms.

Rough idling and problem related to this often indicate a damaged PCM. But there are hundreds of other possible reasons for this. We will also suggest you the same. Check the PCM of your vehicle if you see the following symptoms in your vehicle-

  • Vehicle stalls
  • You will face the check engine light issue
  • You won’t be able to start the vehicle
  • You will see poor performance of the engine

5. Exhaust leak

Exhaust leak is one of the serious problems you will see in the 6.4 Hemi. However, you must not confuse this issue with the tick problem. Due to exhaust leak you will not only feel rough idling but also see a bad fuel economy. Because the leak won’t make it possible to deliver the usual fuel to the engine. Let’s have a look at the symptoms that often indicates an exhaust leak-

  • Follow the check engine light. The check engine light is a great indicator of this problem.
  • You will notice a very bad fuel mileage as your vehicle will start to use more fuel than the average.
  • While you are driving, sometimes you may notice that the gas pedal is vibrating. Yes, that is only because of an exhaust leak.

6. Gear picking problem

Another common problem of the 6.4 Hemi is that the truck will start shifting and downshifting. It is a very concerning issue as you will find it very hard to discover the core reason for this problem. Experts often suggest that there is a problem with the transmission. That is why the truck is reacting like this.

Well, there is nothing wrong with that assumption. But before jumping into spending tons of money, you should do another minor check. This downshifting problem emerges from the throttle bell crank most of the time. If you find out that is the reason behind this case, you are going to save a lot of money.

You can check the throttle bell crank by going under the hood. First, watch out for the throttle body. After finding the body, look out for a cable that ends behind a tiny plastic piece. And after the plastic piece, you will be able to see the throttle bell crank.

7. Truck stalls

The last but not the least of the common problems of 6.4 Hemi is the stalling problem. There is a possibility that you may face this problem at any time while driving down the road. You will see the vehicle going back and forth more than once.

And if stalling is the issue, you may even find out that the vehicle is not starting on the first try. In that case, you have to turn on the ignition a couple more times to get the job done.

6.4 HEMI Engine Failures Common Problems

What is 6.4 Hemi with MDS

6.4 Hemi is a very renowned and reliable engine for various reasons. You will find out that the MDS (Multi-Displacement System) is one of the key reasons among them. Although it is a completely new technology in the market and had some troubles synchronizing with the engine, it is still a huge advantage over the other competitors.

6.4 Hemi is a V8 engine. That means it has eight cylinders. Will you need all the power from this big engine to run lighter tasks like regular driving with your vehicle? The answer is pretty simple. No. You don’t need all the power from this engine. A regular v4 engine would pretty much do the job.

The MDS technology does this job particularly. It makes sure that four of the cylinders remain shut down while performing lighter tasks with the engine. In that way, you will be able to save half of the power from the engine and thus half of the fuel’s money. Isn’t it amazing? We think so. With some tweaks in the technology, it can be a blessing for RAM truck users.

FCA 392 HEMI Transmission Failure

What is FCA 392 Hemi? Does this indicate another thing that is not related to this article? Well, the name seems like it. But it is not. FCA 392 is just another name of the 6.4 Hemi like FCA 6.4 Hemi, Hemi 392, 392 Apache, etc. All these names simply refer to 6.4L v8. 

We have already mentioned this problem in the most common problems of 6.4 Hemi. This engine creates problems related to transmission especially when it is equipped with Ram 2500 or Ram 3500 series’ trucks. 

We know what the functions of these trucks are. They are the specialists when you consider heavy loads and heavy towing. But it comes with a cost. That is you are going to dive into transmission and misfire problems with the engine quite often. 

Nevertheless, Chrysler, Jeep, and the infamous Dodge can always have problems related to transmission. We can’t just remove it out of possibility. 

6.4 HEMI Transmission Failure Symptoms

Although the symptoms are quite confusing with that of the fluid problem symptoms, it is worth a shot to know about these symptoms. If you do know, you are in a very good position as you would have to check the fluid level anyway. The following are the indicators that the transmission of your vehicle’s engine is not up to the mark-

  • Rough shifting
  • Missing gears
  • Clunking sounds

Even though these are not the only ones, they are strong indicators of possible bad transmission. After checking the fluid level, if you get convinced, change the transmission altogether. 

Year-wise 6.4 Hemi problems

Do you want to know the problems in more detail? No worries. We are going to cover this section too. Let’s have a look at the problems of this mighty engine year-wise. 

2021 RAM 6.4 hemi problems

The main problems you will face in ram 6.4 Hemi in 2021 are-

  • Transmission failure
  • Tick sound
  • MDS failure
  • Misfire

2020 RAM 6.4 hemi problems

Although you will find almost every common problem in this year’s version, let’s have a look what are the tiniest differences-

  • Oil leaks
  • Loose gasket
  • Coolant leak 

2020 Ram 2500 6.4L V8 Hemi Review

2019 RAM 6.4 hemi problems

  • Transmission problem
  • Problem while heavy towing 
  • Poor gas mileage

2018 RAM 6.4 hemi problems

  • MDS failure
  • Check engine light
  • PCM problem

2017 RAM 6.4 hemi problems

  • Stalling problem
  • The most common tick sound
  • Transmission problem

392 HEMI Background Info 

As we mentioned before 392 Hemi is just another name of 6.4 Hemi. 392 Hemi and 392 Apache are the most common names of this engine. The reason behind the 392 is it actually tells us the size of the engine in cubic inches. And Apache is the codename of 6.4 Hemi. We think now the 392 Hemi name carries a meaning to you. 

392 hemi hp

There are slight differences between the 6.4 Hemi and 392 Hemi crate engine as the 392 crate engine is a little bit stronger. If you care for performance, the 392 Hemi crate engine is the obvious choice. 

6.4 Hemi got its introduction in 2011, in SRT8 models. Back in that time, this engine was able to provide 470 torque and 470 horsepower. In 2015, the output became even better, the horsepower was 485 and torque was 475 lb-ft. However, you will get the low-end variant of the engine in Ram 2500 and 3500 to ensure better-towing capacity and fuel economy. 

392 Hemi Hp

The 392 Hemi V8 is a 6.4L engine that can deliver 485 horsepower with 475 lb-ft of torque. It can easily achieve 0-60 mph in just over 4 seconds and is available only on the R/T Scat Pack model. 

What is 6.4 HEMI 

6.4 Hemi is actually a kind of successor of Hemi 5.7. The engineers took a lot of inspiration from 5.7 Hemi while building the 6.4 Hemi. Though 5.7 Hemi Problems with its parts. And 6.4 Hemi is the production version of its big brother 392 Hemi crate engine. Dodge SRT8 was the first user of this engine in its chassis. The 6.4Hemi is also a pretty strong, reliable engine.

6.4 hemi crate engine

However, in 2014, a better and refined version of 6.4 Hemi was out in the market. It was easily possible to equip this engine with the likes of Ram 2500 and Ram 3500 trucks. Along with the Ram trucks, it was also introduced in some other renowned brand vehicles. 

ram 6.4 hemi specs

RAM 6.4 HEMI Specs Chart

Material of cylinder blockCast iron
Fuel typeGasoline
Cylinder numbers8
Valves per cylinder2
Layout of valvetrainOHV
Internal combustion engineFour stroke type
6.4 liter Hemi HorsePower366-485 hp
Torque429-475 lb-ft (2019 Ram 2500.)
Bore103.9 mm
Stroke94.6 mm
Weight227 kg (500 lbs)
Firing order1-8-4-3-6-5-7-2
Oil change interval6,000 miles or 6 months
Engine oil capacity6.7 l with oil filter (7.0 qt)
Production years2011-presesnt
ManufacturerChrysler, Mexico

Features of 6.4 HEMI Engine

  • Uses cast iron as a cylinder block material
  • Uses gas as fuel
  • Has 8 cylinders
  • Can provide up to 485 horsepower
  • Has a torque of 475 lb-ft
  • Weighs 227 kg
  • Has 6000 miles of oil change interval 

Ram 6.4 Hemi longevity and 6.4 Hemi reliability

It is hundred percent right if you have concerns about the longevity of the engine you are going to choose. Leave all the features, leave all the numbers promised by the production companies. The one thing you really should care about is the durability of the product you are going to use. 

Yes, Ram 6.4 is pretty much durable. It got its introduction in the year 2011. From then, it continued to hold its reputation as a beast at its function. Despite the frequent problems you are most probably going to face, you can pretty much rely on this engine. What is 100% pure? Nothing. 

What Cars Use the 6.4L HEMI? 

This engine is really popular among enthusiasts. You will know that after discovering the list of vehicles that use this engine. Let’s head into the list-

  • Ram 2500
  • Ram 3500
  • Dodge Challenger SRT8, R/T Scat Pack, SRT 392
  • Dodge Charger SRT8, R/T Scat Pack, SRT 392
  • Dodge Durango SRT
  • Chrysler 300 SRT
  • Jeep (Grand Cherokee) SRT

In this list, Ram 2500 and Ram 3500 vehicles have multiple options in the engine. You can choose different variants in these mentioned models. Anyway, 6.4 Hemi is the option for every single vehicle mentioned above. 

6.4 hemi lifter failure

The lifter failure is another common problem of 6.4 hemi. This problem is a serious one. You need to take care of it as soon as possible. Okay, we get that. But what is the reason behind this lifter failure? 

We can say that almost every time the problem occurs due to improper cleaning. However, the lifters may wear out as they ages. But today we are not going that way. If you do the cleaning wrong, there will be debris in the passage. And a clogged passage is not the thing you want for sure. 

It will harm the oil to reach the lifters. Thus the lifters will stop pumping and you will hear some excessive noises. And this does not end up right there. If you don’t take care of this situation, the valve tip, pushrod, and rocker arm also will go bad. That is why it is an emergency as soon as you find out there is a problem in the lifters. 

Possible Solutions of Problems with 6.4 HEMI Engine

Have you had enough of the problems? We are on the same page with you in this regard. Let’s have a look at the possible solutions to the most common problems with the 6.4 Hemi engine-

1. To address the transmission issue, first, you have to have confirmation about the issue. Many of the drivers get the transmission replaced although the problem was in the fluid levels. By checking the fluid color, you can determine the transmission problem. 

If that is the case, replace the transmission. Though replacing the transmission is a costly process, you have to do that immediately. Otherwise, you will damage your vehicle severely. 

2. If the MDS becomes faulty, you can resolve the issue by taking the following steps. You can always turn off the MDS manually if the problem is serious. And if you do not want to turn off the MDS or remove it, you can use a Diablo tuner to get it disabled permanently. 

3. Ah! The infamous tick sound of 6.4 Hemi. You can get rid of this annoying sound by using the right oil or fixing the lifter. These steps should be enough to get the sound contained. 

4. Who wants an exhaust leak in their vehicle? It is not only bad because you have to spend money but also you may even have to stop right in the middle of a road due to fuel shortage. You can get out of this problem by sealing the holes in the exhaust with the help of exhaust putty. It will be just enough to keep you out of trouble. 

5. A damaged PCM is always a heavy pain to bear. You have to replace the damaged PCM with a good one as going for cheap won’t be good for the long run.  

6. To get rid of the stalling problem, first, check the connection of the battery. If the battery is not connected properly, you will face this problem. Another reason for this problem is the damaged wires in between the vacuum pump and the fender. Replacing those wires may get you out of trouble in this case. 

7. As a problematic throttle bell crank is no good for your vehicle as it won’t be able to pick the gears correctly, you might want to replace that. You will most probably make it out if you do this. 

Pros & Cons of 6.4L Hemi Engine

If you compare the 6.4L Hemi engine with other regular engines, it is an absolute beast. But with advantages, it also has some disadvantages. Let’s have a look at the pros and cons of 6.4L Hemi. 


  • The cylinder block’s material is cast iron
  • Has a massive horsepower 
  • Is really good for heavy towing
  • Has MDS technology
  • Can diminish the combustion heat with the help of effective oil spray
  • Has all the fame and reliability


  • Tick sound
  • Transmission problem
  • Exhaust leak 

Maintenance Tips

The proverb “prevention is better than cure” also applies to the 6.4 hemi engine very well. You will always want the best out of an engine like 6.4 hemi. And in addition, you will also want to save as much money as possible. You can do both if you maintain the engine with a little bit of extra care. Here, we are giving you some tips to keep the engine in a healthy state for a long time.

Air Filter

The air filter is an important part to keep fresh air coming to help the combustion process. It is ideal to change the air filter after every 15,000 miles.

Spark plugs

Replace the spark plugs after every 100,000 miles. You won’t face most of the problems, especially the starting problem.

Oil change

Another important task is to change the engine oil before 6,000 miles. It will help you keep a distance from a lot of problems.

Rotation of tires

Rotating the tire after every oil change is also necessary as unbalanced tires can lead the tires to uneven wear.

Transmission service

Another thing you should not forget is to flush the transmission every 60,000 miles. You can save a lot by doing so as it will prevent a lot of problems from happening.

Coolant service

If you want that your vehicle runs pretty well even in extreme temperatures, make sure to have the coolant service every 150,000 miles.

Serpentine Belt

This naïve looking part is very important for the engine. Make sure to change the belt every 100,000 miles.

PCV Valve

Another task you should not forget is to keep the PCV valve maintained every 100,000 miles.

6.4 Hemi crate engine cost

Mopar Hellephant 426 Supercharged Hemi Crate Engine, it carries part number (P/N) P5160194 and wears a price tag of $29,995.


Is the 392 hemi a good engine?

Yes, it is. The 392 hemi is a great deal as you will get loads of features along with the great after-sale service from the manufacturers. It is a great engine to do day-to-day tasks. This engine can also perform in extreme conditions as it has 485 horsepower and 475 lb-ft of torque to support the vehicle.

How many miles will a 6.4 Hemi last?

One thing for sure. This engine won’t disappoint you if you maintain it well. If you ask us how long do 6.4 hemi engines last, we will say that you can expect a maximum mileage of anything beyond 250,000 miles. We have cross-checked the data with reviews from some of the forums too so that you don’t get only paper-based information. The users were also happy with this engine.

What is the gas mileage on a Ram 2500 6.4 Hemi?

We can’t tell you the exact number as the number may vary in different situations. But if you maintain things well, you can expect an average of 13 mpg on town and over 15 mpg on the highway from ram 2500 6.4 Hemi.

How much HP can a 6.4 Hemi handle?

After the refinement, the horsepower of the 6.4 liter Hemi got increased. Now it can handle up to 485 horsepower. However, if you do some modification, it is pretty easy to touch even more.

Is the 5.7 or 6.4 Hemi better?

Definitely 6.4. In technology, the next product of the series is better in almost every case. It is the same with 6.4 hemi. This engine followed the footsteps of 5.7L hemi. 6.4 hemi got some of the features of 5.7 and in extra, it has some more features to offer that are not present in 5.7 hemi. That means 6.4 is obviously a better choice.

Is the 6.4 Hemi reliable?

6.4 Hemi is a pretty good engine. It got its reputation with the features and longevity. You can get a lifetime of over 250,000 miles easily if you maintain the engine well. So, yes. 6.4 hemi is a reliable engine.

Is 6.4 Hemi a big block?

No, it is not. As all the modern hemi engines are small blocks, this engine also falls within this. That is why it is a small block.

Does 6.4 Hemi need premium gas?

No, it does not. You will be pretty much okay with either 87 or 89 rated octane. Even though most of the modern owners recommend 89 in the manual, 87 will be okay for the engine too.

How can I get better gas mileage in my 6.4 Hemi?

You can get better mileage with your 6.4 Hemi by following the steps mentioned below-

1. Maintain the PCV valve regularly

2. Get transmission service on a regular basis

3. Change the air filter when the time is right

4. Replace the spark plugs when it is necessary

5. Change the oil every 6,000 miles

What is faster scat pack or SRT?

Definitely the SRT. Even though both of them have the same power as they use the same engine, due to cost-cutting, the breaking and handling are not good in the scat pack. Thus it will be slow in the races.

Is the 6.4 Hemi good for towing?

Yes, it is. It has 475 lb-ft of torque to ensure your heavy towing. But you have to make sure the transmission system remains in a healthy state. Because most of the time, the towing problems occur due to faulty transmission.


So, you have chosen the end. We are joking, you know that. In this whole journey throughout the article, one thing seems to have the most important of them all. Good maintenance. Yes, if you can maintain the engine with the utmost care, you will easily hit the top numbers. Till then, stay safe. And hey, sharing your thoughts in the comment box is not a crime!

Leave a Comment

Your email address will not be published. Required fields are marked *