6.4 Hemi Engine Problems And Specs

The legendary 6.4 Hemi V8 is an incredibly dependable engine, however, it's not perfect. Common problems that plague the 6.4 V8 can be small and easy to fix, but they can also sometimes be way more troublesome. In order to get a good understanding of what to look out for, be sure to go through this article.

6.4 Hemi engine problems

• Hemi Multi-displacement systems issues
• Hemi transmission issues
• Engine ticking problems
• PCM issues
• Exhaust leak
• Electrical issues
• Towing issues
• Misfiring
• Unable to pick a gear
• Engine stalling
• Towing over-revving system malfunction
• Wrist pin issue

Multi-displacement System Issues

The Multi-Displacement System is designed to shut off a bank of cylinders while cruising to save fuel. This system enables many manufacturers these days to reach their efficiency standards while still offering large and powerful engines. However, this technology can also cause lots of engine issues because it’s so new, and that’s especially the case with the 6.4.

Hemi Transmission Issues

Hemi transmissions have always been known as somewhat problematic, and many people believe that transmission issues are the most common engine-related issues the 6.4L V8 has. Be sure to check out the transmission fluid first as sometimes these transmissions do leak. Furthermore, if your car runs rough, be sure to take it in for an inspection.

Engine Ticking Problems

An engine ticking problem is also a constant worry with a 6.4L Hemi V8, but the difference here is that many things can cause this issue. If it is only ticking on start-up and it goes away, you ought not to worry. However, if ticking persists it is likely due to lifter issues and this should be looked over by a professional.

PCM Issues

The 6.4 Hemi V8 is often plagued by a damaged PCM. The easiest way to spot these engine problems is if your car is idling rough. Be that as it may, there are a dozen of different symptoms which could indicate a faulty PCM. Here are the most common ones:

• Unable to start the vehicle
• Check engine light
• Subpar performance

Exhaust Leak

Exhaust leakages are sadly also apparent with many 6.4L V8 Hemi engines. If you sense the engine performance is decreasing, or your exhaust sound is way louder and sharper, chances are that your exhaust system has a puncture. You should deal with this issue immediately because it can also cause bad fuel economy.

Electrical Issues

Electrical issues can be detrimental to your engine as they can sprout in many different directions. More often than not, if a small electric problem persists, it can cause other systems to malfunction, and this can lead to more serious issues. So if your systems start acting weirdly, be sure to inspect the car asap.

Towing Issues

Even though the 6.4L Hemi engine is good for towing, it can sometimes fail to deliver if it's under constant towing pressure. That being said, if you are often towing with your 6.4 V8, you ought to skip buying this engine, and opt for diesel instead. Diesel trucks have more torque which translates into more pulling power thus they are perfect for towing.

Engine Misfiring

Engine misfiring can be caused by many underlying problems. In this instance, engine misfiring can be linked with lifter rollers, an MDS solenoid issue, or with just the spark plugs. The 6.4L Hemi V8 uses 16 spark plugs, 8 per cylinder, and if these are not properly maintained they can cause misfires. To be fair, faulty sparkplugs are almost always the ones to blame.

Unable To Pick A Gear

The transmission offered with the 6.4L Hemi is known to cause a myriad of issues, but the one that seems to be the most concerning is the uncontrollable downshifting. This issue is mostly associated with the throttle bell crank, so be sure to check it before you jump to any conclusions. The throttle bell crank is located under the hood behind the throttle body.

Engine Stalling

It’s no secret that the 6.4L Hemi is not the most sophisticated engine on the market, but it's not normal for the engine to idle unevenly because this can often cause the engine to stall out completely. This issue is commonly associated with the aforementioned PCM module, but it must be addressed soon enough because it can cause many more issues even beyond the PCM.

Towing Over-revving System Malfunction

This engine comes with a system designed to protect the engine from over-revving itself while towing heavy loads. Even though the system does work adequately most of the time, it can sometimes misinterpret the situation it is in which causes the engine to limit the top speed up to 35mph. Moreover, this also causes the engine to use more fuel.

Wrist Pin Issue

A wrist pin is a mechanical component used to form a bearing for the crank, and the early 6.4L Hemi engines were sometimes known to have wrist pin issues. The only way how one can properly diagnose this issue is when the truck emits a loud noise after a cold start. This issue is commonly associated with the 2014 6.4L Hemi models, and the noise usually stops after the truck is warm enough.

Main Features Of The 6.4L Hemi V8

The 6.4L Hemi V8 is widely regarded as a dependable and efficient engine that was packed with lots of clever features such as two spark plugs per cylinder which greatly reduces both fuel consumption and harmful emissions. This engine also offers a dedicated oil/water cooler which was designed to offer additional cooling while under heavy stress such as towing.

The strong suit of the 6.4L Hemi is the ability to efficiently remove heat from the engine thanks to a clever piston cooling jet design. The cylinder heads are made out of aluminum which ensures that the performance of the 6.4L is continuously on point. This engine is also compatible with different sorts of fuel such as 87 octane fuel even though the recommended fuel type is 89 octane.

Here Are The Engine Specs Of The 6.4L Hemi V8

FAQ Section

Is The 6.4L HEMI a Good Engine?

For more than a decade, the 6.4L HEMI V8 serves as a reliable and powerful workhorse engine. As such, the 6.4 might not have impressive efficiency, but thanks to its above-average reliability and pulling power, the 6.4L Hemi V8 is definitely a good engine.

How Long Can The 6.4L HEMI V8 Last?

It's extremely difficult to suggest how much an engine can truly last, but on average, with perfect maintenance and service schedules, the 6.4L HEMI is good for 250k miles at the very least. Many things affect how long an engine can last, but if you do everything right, 250k miles is a given.

What’s The Most Reliable HEMI Engine?

According to a couple of online sources, the 5.7L HEMI is probably the most reliable HEMI engine out there. These can warry between different models, but the 5.7 is the shining star. It’s worth mentioning that the 6.4L Hemi is also at the very top when it comes to the most reliable Hemi engines out there.

Is The 6.4L HEMI V8 Strong Enough?

It's hard to suggest that 410hp and 430 lb-ft of torque are anything else but adequately powerful. However, it depends on what you use your car for. If you want a workhorse truck or a daily driver, the 6.4L HEMI is strong enough. It might not be up to par with other V8s with similar displacements, but it does make up for it in the reliability and efficiency department.

What’s The Fuel Efficiency Of a 6.4L HEMI V8?

Fuel efficiency is hard to pinpoint, but if you consider everything, around 15MPG is a reasonable estimate. These numbers vary significantly depending on which 6.4L truck you are driving and the way you drive in general.