The 6.4 HD Hemi Thread

[birchit]

The only other thing I've heard fail is the OD clutch itself, from being beat on. If you don't beat on it - i.e., use the tow shift program and lock out of double O.D. (6th 'gear') when towing, it should be fine.

Then get the oil temp down by getting rid of the oil thermostat.

Keep in mind the replacement valve body requires a PCM re-learn, it must be re-set either by dealer or your choice of tuner. Guys have had good luck with HP Tuner.

I have a tuned ECU from Diablosport which I use since I bought this truck with 0 miles on it. So the gear timing is faster and better for our mountains here. I guess they also changed the oil pressure in the transmission...but I do not know it. It is always a secret what Diablosport really did. But it works till now the 120.000 miles perfect for us here in Germany.

By the way: The oil temperature is measured was the engine oil (226,4°F), not the transmission oil. That is maximum at 162°F...in 4th gear with low speed (50mph).

I will get rid of the thermostat for sure.

Thanks for your help.

 

[cmosesak15]

I just got my 2014 6.4L CC. I bought it for better towing and to go back and forth to work, I have another car for just regular driving around and errands. I am looking at some cold air intakes and a throttle body spacer. Also possibly a tuner This is a big heavy truck. I would hope to have it feel more responsive on the pedal at go. But, It does exactly what I want it to do, so the tuner, im on the fence about. It would be nice, but I would only want a modest gain in power and as much gas mileage as possible, although I knew what I was getting into so no big deal. I think I am currently at about 12.5mpg - but I have only put 200 miles on it so far.

 

[Wild one]

I just got my 2014 6.4L CC. I bought it for better towing and to go back and forth to work, I have another car for just regular driving around and errands. I am looking at some cold air intakes and a throttle body spacer. Also possibly a tuner This is a big heavy truck. I would hope to have it feel more responsive on the pedal at go. But, It does exactly what I want it to do, so the tuner, im on the fence about. It would be nice, but I would only want a modest gain in power and as much gas mileage as possible, although I knew what I was getting into so no big deal. I think I am currently at about 12.5mpg - but I have only put 200 miles on it so far.

Save your money on the cold air and throttle body spacer,neither do much except create noise,and put that money towards a set of long tube headers,that'll actually give you an off idle to redline power increase with a good custom tune

 

[cmosesak15]

Save your money on the cold air and throttle body spacer,neither do much except create noise,and put that money towards a set of long tube headers,that'll actually give you an off idle to redline power increase with a good custom tune

I just came to the same conclusion after reading through these forums yesterday. Not on the headers, but just not wasting money on the other items. Any suggestions on which headers? I will take a look too.

 

[buckeyexx]

I just came to the same conclusion after reading through these forums yesterday. Not on the headers, but just not wasting money on the other items. Any suggestions on which headers? I will take a look too.

If you want more response at the pedal then try a pedal Commander or something like it. There lots of different brands out there but that one is the most popular. Just don’t be fooled by it. It just adjusts your throttle response sensitivity and doesn’t add power but it will feel like it.

 

[SniperDroid]

New to the thread... I've had my 6.4L for almost three years now. Only 10k of the 19K on the odometer are mine, but I love the engine and it's performance while towing the 30 ft Travel Trailer (about 7500 lbs). It certainly pulls it easier than the Ford F150 gas I first started with, and the used F250 Diesel I poured money into like a boat! The only thing I found I don't like is the Fuel Economy while towing... average 9 to 9.5 (measured) on the highway. Ill try to take some time and read the older posts on the thread for solutions. Looking forward to reading everyone's thoughts...

 

[pbzzz]

exhaust note is sweet and just right but last 2-3 ft of exhaust system is bfOOk OOOgly

 

[pbzzz]

changed oil/filter at 500, 1500 then every 2000-4000 miles .Rid of any machining debris early on . Also - anything that Mobil1 wont do . . . I don't need done .

 

[pbzzz]

of my 6-7 oil and filter changes 3 have been Mob-1 0/40 . No codes and never a problem . The other changes were all Pennz PPP .

 

[pbzzz]

we pull a 5th wheel . . . rear bed camera view is not large enough / clear enough to really help -wouldn't order it again . Limited slip rear = DEFINITELY

 

[pbzzz]

2022 2500 Bighorny hemi - Cargo camera only displays in reverse with programable option to show for a few extra seconds after leaving reverse

 

[BlackGold6.4]

we pull a 5th wheel . . . rear bed camera view is not large enough / clear enough to really help -wouldn't order it again . Limited slip rear = DEFINITELY

Yes agree, Ordered mine with 4.10's and sure grip... a must for this set up.

 

[KLook]

Does anyone know what the cylinder compression should be when new? I am going to replace the spark plugs at 153,000 and will do a compression test. I feel the power is down when towing my camper. Just looking for a baseline. Even better if someone knows what they got at about those miles.

 

[Wild one]

Does anyone know what the cylinder compression should be when new? I am going to replace the spark plugs at 153,000 and will do a compression test. I feel the power is down when towing my camper. Just looking for a baseline. Even better if someone knows what they got at about those miles.

Post your numbers when you're done.As long as they're all with-in 15 /20 psi of each other that's all you need to worry about. You're not gonna change them to match another trucks numbers so why even worry about what another trucks psi numbers are.All you're gonna do is stress yourself out worrying

 

[Shark]

Sick to my stomach. My Engine just blew. 2016 with 96,000 miles. 6.4L, Laramie. Needs a new engine and entire cooling system. Estimate is $18,000+. I'm retired and can't afford that. Also can't afford to lose the truck.

 

[HEMIMANN]

Sick to my stomach. My Engine just blew. 2016 with 96,000 miles. 6.4L, Laramie. Needs a new engine and entire cooling system. Estimate is $18,000+. I'm retired and can't afford that. Also can't afford to lose the truck.

"Blew" how?

 

[Shark]

"Blew" how?

Coolant hose blew off the radiator, OAT and engine oil everywhere - like a slasher film. Engine block cracked or head gasket? They don't know yet due to all the fluids. No warnings, no overheat, gauges all looked good - oil temp, trans temp, oil pressure, coolant temp, everything.

 

[Hootbro]

Coolant hose blew off the radiator, OAT and engine oil everywhere - like a slasher film. Engine block cracked or head gasket? They don't know yet due to all the fluids. No warnings, no overheat, gauges all looked good - oil temp, trans temp, oil pressure, coolant temp, everything.


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Yeah, that is nasty. You could save a bit with a independent shop putting in a salvage pull.

 

[olyelr]

Coolant hose blew off the radiator, OAT and engine oil everywhere - like a slasher film. Engine block cracked or head gasket? They don't know yet due to all the fluids. No warnings, no overheat, gauges all looked good - oil temp, trans temp, oil pressure, coolant temp, everything.


View attachment 560094 View attachment 560095

That sucks for sure! Ive been feeling good about my ‘16 6.4 with 115k on and never had any issues at all with the motor (or anything else for that matter), but this certainly makes me cringe. I take it you didnt opt for the lifetime warranty?

 

[Shark]

That sucks for sure! Ive been feeling good about my ‘16 6.4 with 115k on and never had any issues at all with the motor (or anything else for that matter), but this certainly makes me cringe. I take it you didnt opt for the lifetime warranty?

I wasn't offered a lifetime, I grabbed the "Platinum Plus" for 84 months or 100,000 miles. I'm okay on the miles, but over the time limit. I hadn't had any problems at all either - until it went p.o.o.f !

I have a car on order to replace my - ahem - Prius with over 200,000 miles. I guess fixing the truck means I'm stuck with that beast. I just have a hard time spending 18k (that I really can't afford) and then I'll worry the tranny or something else will go next. But I can't just dump a $60,000 truck either. Decisions decisions...