The 6.4 HD Hemi Thread

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Fitz-0518

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They are loud but do they make electric fans that will cool a 6.4 under load and at high altitude?
Sanda, I have not finished my home work on what type of thermo electric fans choices we have. I do know they are available. Will share what I find when I get ready to order one. Need to also talk to my Tech to make sure that he is Ok with installing.
Focused now on getting the exhaust leak fixed on my 2018 2500 FCA replacement truck #2. Have all the OEM MOPAR parts needed including headers. Having my Tech do the work. After 1 year of letting dealers try to fix truck #1, can't trust the dealers. Fitz
 
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sandawilliams

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Sanda, I have not finished my home work on what type of thermo electric fans choices we have. I do know they are available. Will share what I find when I get ready to order one. Need to also talk to my Tech to make sure that he is Ok with installing.
Focused now on getting the exhaust leak fixed on my 2018 2500 FCA replacement truck #2. Have all the OEM MOPAR parts needed including headers. Having my Tech do the work. After 1 year of letting dealers try to fix truck #1, can't trust the dealers. Fitz

Thanks for doing the research for us.
 

ETX Ram

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Sanda, I have not finished my home work on what type of thermo electric fans choices we have. I do know they are available. Will share what I find when I get ready to order one. Need to also talk to my Tech to make sure that he is Ok with installing.
Focused now on getting the exhaust leak fixed on my 2018 2500 FCA replacement truck #2. Have all the OEM MOPAR parts needed including headers. Having my Tech do the work. After 1 year of letting dealers try to fix truck #1, can't trust the dealers. Fitz
Following this now Fitz. Interested to know how you come out with electric fan project.
Lee
 

Fitz-0518

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Sanda, Lee, I believe I have gotten to the bottom of what we need to know about our fan noise. This is what I learned.
1. Most of the high heat fan noise comes from our thermal fan clutch. When replacing this part, it should be ordered by VIN #. The aftermarket fan clutches are designed to be used on many different applications. They are often designed to activate/engage at a lower temp than what the OEM clutch would engage at. On my 03 5.7. The activate temp by Vin # is 150*. When I replaced my radiator, pump and fan clutch my tech was not able to locate a OEM clutch. He installed a Dorman that came on at 120*. I have since located an new old stock fan clutch from a dealer in Kentucky. The 120 temp clutch was coming on too often and staying on to long.
2. Now to the electric high heat fans. I replaced the one on my 03 a couple years ago with a application specific VDO fan. Perfect results, No issue.
On the 2018 6.4 I have learned that the electric fans were not spec'd for noise. As a result the parts vendor is producing a unusually noisy fan when it engages. Dealers are telling customers who notice this, normal and customary. My tech is looking for a direct replacement fan that would be as effective but quieter. Nothing yet. Fitz
 

NewBlackDak

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79126K miles, and I have an exhaust leak at the rear of the driver side manifold. Currently it goes away when everything heats up. Anyone else seen this on a 6.4L?


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Fitz-0518

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Common on "some" 2500 6.4 engines. Assembly defect per dealers and FCA. When the tightening sequence is not followed or the torque specs are not followed, we get an exhaust leak. My first 2018 6.4 was replaced by FCA for this problem. The replacement came in and it has the same exhaust leak. Only heard on cold start. Screech/hiss sound. The rear exhaust manifold bolts on the driver and passenger side are the bolts that most often snap from the expansion contraction.
My POV, FCA has now adopted a Fiat, Renault mentality. Design and make them cheap, throw them together and focus on the bank deposits.
 

NewBlackDak

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Common on "some" 2500 6.4 engines. Assembly defect per dealers and FCA. When the tightening sequence is not followed or the torque specs are not followed, we get an exhaust leak. My first 2018 6.4 was replaced by FCA for this problem. The replacement came in and it has the same exhaust leak. Only heard on cold start. Screech/hiss sound. The rear exhaust manifold bolts on the driver and passenger side are the bolts that most often snap from the expansion contraction.
My POV, FCA has now adopted a Fiat, Renault mentality. Design and make them cheap, throw them together and focus on the bank deposits.

Screech/hiss is a perfect explanation for it, and only on cold start. Maybe I can convince the wife now that I “need” headers.

On a side note. Might as well change plugs at the same time. Should be much easier with the manifolds out of the way.

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ETX Ram

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Sanda, Lee, I believe I have gotten to the bottom of what we need to know about our fan noise. This is what I learned.
1. Most of the high heat fan noise comes from our thermal fan clutch. When replacing this part, it should be ordered by VIN #. The aftermarket fan clutches are designed to be used on many different applications. They are often designed to activate/engage at a lower temp than what the OEM clutch would engage at. On my 03 5.7. The activate temp by Vin # is 150*. When I replaced my radiator, pump and fan clutch my tech was not able to locate a OEM clutch. He installed a Dorman that came on at 120*. I have since located an new old stock fan clutch from a dealer in Kentucky. The 120 temp clutch was coming on too often and staying on to long.
2. Now to the electric high heat fans. I replaced the one on my 03 a couple years ago with a application specific VDO fan. Perfect results, No issue.
On the 2018 6.4 I have learned that the electric fans were not spec'd for noise. As a result the parts vendor is producing a unusually noisy fan when it engages. Dealers are telling customers who notice this, normal and customary. My tech is looking for a direct replacement fan that would be as effective but quieter. Nothing yet. Fitz
Fitz - Appreciate the info and the associated followup. I'm going to continue following along. My fan doesn't appear to be noisy as of yet - 6.4L 2500, but always keeping a tuned ear out for this as well as any Hemi tick or exhaust noise.
Lee
 

Canadian Mopar

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Update on my search, found a good deal on a used 2017 2500 6.4L. Already has a K&N CAI. The PO also took out the resonator so it sounds pretty awesome!
Already noticed quite a bit of difference from the 2011 2500 5.7L in the drive home, see how it does with a load.

WP_20190722_21_10_59_Rich_LI.jpg
 

NewBlackDak

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I sold my travel trailer, and bought a fifth wheel. I’m committed to keeping the truck for at least another year.
The fiver weighs right at 2000 lbs more, is 15” taller, and is about 18” shorter.
The drive home was a much better tow, and while my lie-o-meter is almost always 1-2 mpg off I was getting the same 11-12mpg displayed as I did when I towed the travel trailer. It didn’t struggle for power once, and is rock solid on the road. We’re leaving for a shakedown trip this afternoon, which has us going over a 6300ft pass. I’ll update when we get back.


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NewBlackDak

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Made it with no issues. Started at home ~4500ft, up and over ~6300ft, and back down to ~4900ft. Set the cruise at 60(like I always do). It shifted into 3rd near the top of the hill, but had no problem holding speed on the way up. Manually selected 4th, and it controlled the speed on the way down.


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Highwayman1

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Love mine. 13-15mpg around town and 17-18 Highway. It will do everything that I need it to do. It's a '17 , bought it new.fbf38a3a766d20247c6f5022cbca6a5a.jpg

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NewBlackDak

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Are there any inside-the-coil bags for the rear of the 2500?


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Rwgarrison23

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Anyone here have the lugging issues going up the hill? I live on a hill which takes about a mile to get up to and between 15 to 25 mph limit going up. It lugs bad and sometimes wont down shift for the life of me. I bought the truck used, 2018 2500 6.4. It's going back to the dealer to have it checked over. But, after some reading here, pedal commander seem to solve that issue? Anyone have experience with them?
 

1stindoor

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I'm not really sure how I missed this sub-forum. I have a 2018 2500 Mega Cab, 6.4L. I traded in my 2500 HD Sierra for it. First time Ram owner after nearly 40 years with GMCs. I'm loving this truck. I've had 2500s for nearly the last 15 years, so I'm used to the stiffer ride and gas mileage. I average about 14.5 most of the time and about 11-12 while towing my boat.
 

Robert A Knight

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hey new here, but i traded my 2017 2500 with the cummins that was having DEF issues.
I now have a 2019 with the 6.4 hemi.
so far i like this truck if i could ever get it out of the service dept.
2 AC vents blow low 40's and 2 vents blow 60, service cant figure it out
But the truck rides good, and is very strong.
Gas milage is not as good as the cummins
 

NewBlackDak

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Has anyone who has done gears hit the first gear hold? I know it’s less likely with taller gears, but it already has you locked down to 31 mph(assuming stock tires with 4.10s). At 4.56 you’re chugging along just under 28, and 4.88 is a hair over 26 mph.


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