Hemi 6.4 Gas Engine Knock

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Bill Hartman

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2016 Ram 2500 with 23500 miles. The truck is still under warranty. So last week before my wife and I left on vacation I took it to my local dealer for an inspection, oil change, and tire rotation. The next morning we headed down the road. Stopped at about 100 miles and had lunch, no issues. Went another 100 miles to our destination and when my wife got out of the truck, while it was running, we hear this terrible knocking noise. Remember, this is gas not diesel: HERE IS THE VIDEO. Sounds like lifters/oil issue to me. It was louder on the right side and from underneath. If you turned the radio and air off you could hear it in the cab with the doors closed and windows up.

I checked the oil and all other fluids. All was normal, all gauges normal, no warning lights of any kind. I called my dealer from 200 miles away and they suggested I get it to another dealer close to my location, which was 25 miles away. I called them and they were kind enough to squeeze me in. I got to the dealer and it was making the same noise, but while they had it, it would stop doing it after 3-5 minutes. He put me in a loaner jeep compass (geez what crap) so I could continue on vacation. He called a few hours later and said it was definitely an internal engine issue and offered to tear it down under warranty and figure it out, but I was 200 miles from home and he wanted it a week. He also told me that his technician thought it was safe to drive and noted that in his report. I went back to pick it up. When i got it back, it was not making any sort of noise, and it has not done it since. I drove it 200 miles back home in near 100 degree heat no issues whatsoever. I even got 19.2 MPG on premium fuel.

So I called my dealer when I got home. They told me that if the truck was running normally, gauges normal, and no warning lights, there was nothing they could do. I questioned whether the right kind of oil was put in the vehicle and they said if not, the problem would have gotten worse instead of going away - which I'm not entirely buying.

But bottom line, something really bad sounding is documented and a dealer heard it. But now I'm stuck hoping it doesn't happen again after I exceed my 5 yr/60k powertrain warranty - which is in another 2 years or so. Has anybody else had a similar issue or advice on how I should be pushing this with the dealer? Thanks.
 

Elcy

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Kinda sounds like an exhaust leak
 

turkeybird56

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That's a gas engine making that sound??? Did they forget to put oil in it???? Sounds like either lifter/cam slap/piston slap. BUT I am no mechanic. But if my motor was making sounds like that I would be beside myself, just saying... Does not sound like exhaust leak, but maybe a remote possibility...all IMHO.......
 

mtofell

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Wow... yeah, that's pretty bad. I'd be very suspect of incorrect oil but good luck proving that. The good news is you have it documented and still quite a bit of power train warranty left. So, in the short term I guess just wait and see.
 

Iron Outlaw

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I had a 2013 5.0 f150. One time my wife cranked it up when we were leaving her parents and it sounded like a bad rod knocking. She let it run for about 30 seconds before I got her to turn it off. Cranked it again and it was fine. Dealer acted like I was crazy when I told them about it. Mine was worse and sounded like bottom end noise. It did it again one morning on my way to work, but once again it stopped. I ended up with weird electrical issues also so I ended up trading it in with 36000 miles on it and got my ram I have now. These kind of issues make you lose confidence and suck when you run out of warranty but the problem is obviously there before.
 

chrisbh17

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Maybe loose/backed out torque converter bolts?

Sent from my Nexus 6P using Tapatalk
 

tjfdesmo

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Most likely lifter. I had a Tahoe that did that. It was so loud I had it towed to the dealer. Per GM, they let it idle for almost an hour and it quieted down.

My 6.4 was never that loud, but maybe 50%. Redline 5W40 was the answer for me.
 

MADDOG

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Last time I heard a clatter like that out of a 6.4L was a few years ago. It was my 2014 2500 6.4L powered CC and it was built with undersized wrist pins and the pistons were slapping away at the inside of the cylinders. The clatter was accompanied by a serious rod knock which I don't hear in your video.

They replaced the engine. They had a time & VIN limited service bulletin out on some of the 2014 trucks.

Your's sounds like a lifter or maybe an exhaust leak at the head.
 

Rambojoe

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That sounds like a collapsed lifter to me. Maybe it had a piece of dirt in but cleared it self and pumped up. If it’s running alright, drive it, if it happens again, drive it to the dealership after videoing again and ask to talk the FCA Customer Care.
 

hotkarl

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I would never trust that vehicle again.
That's me though.
Something like that would have me second guessing and finger crossing every time I start the truck and I just can't have that.

You need to escalate this.
That motor lets loose and Ram will try 8 ways to Sunday to **** you out of a repair or replacement. And that is a very, very, expensive motor to replace.
You need to cover your ass.
 

HammerHead

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2016 Ram 2500 with 23500 miles. The truck is still under warranty. So last week before my wife and I left on vacation I took it to my local dealer for an inspection, oil change, and tire rotation. The next morning we headed down the road. Stopped at about 100 miles and had lunch, no issues. Went another 100 miles to our destination and when my wife got out of the truck, while it was running, we hear this terrible knocking noise. Remember, this is gas not diesel: HERE IS THE VIDEO. Sounds like lifters/oil issue to me. It was louder on the right side and from underneath. If you turned the radio and air off you could hear it in the cab with the doors closed and windows up.

I checked the oil and all other fluids. All was normal, all gauges normal, no warning lights of any kind. I called my dealer from 200 miles away and they suggested I get it to another dealer close to my location, which was 25 miles away. I called them and they were kind enough to squeeze me in. I got to the dealer and it was making the same noise, but while they had it, it would stop doing it after 3-5 minutes. He put me in a loaner jeep compass (geez what crap) so I could continue on vacation. He called a few hours later and said it was definitely an internal engine issue and offered to tear it down under warranty and figure it out, but I was 200 miles from home and he wanted it a week. He also told me that his technician thought it was safe to drive and noted that in his report. I went back to pick it up. When i got it back, it was not making any sort of noise, and it has not done it since. I drove it 200 miles back home in near 100 degree heat no issues whatsoever. I even got 19.2 MPG on premium fuel.

So I called my dealer when I got home. They told me that if the truck was running normally, gauges normal, and no warning lights, there was nothing they could do. I questioned whether the right kind of oil was put in the vehicle and they said if not, the problem would have gotten worse instead of going away - which I'm not entirely buying.

But bottom line, something really bad sounding is documented and a dealer heard it. But now I'm stuck hoping it doesn't happen again after I exceed my 5 yr/60k powertrain warranty - which is in another 2 years or so. Has anybody else had a similar issue or advice on how I should be pushing this with the dealer? Thanks.
That’s is Exactly what a stuck lifter sounds like; the reason it went away is because it’s not stuck anymore. It freed up somehow; but the needle bearings in the roller are already damaged. Once that lifter seize it will eat your cam, then your looking at a rebuild. Document Document Document, videos like you posted will be good to have.
 

JohnnyMac

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Drain out all the oil. Floor it for a minute till it really makes a noise. Put old oil back in and take to dealer...lol..jk

Hah! That's what I was gonna say!
 

GsRAM

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Yep, valve train noise. I'd have probably let the dealer where it was at tear it down right then and there. This is one of many reasons I do my own oil changes. I know exactly whats in it. It may be good for 100k plus miles now? Hard to say.....good luck man...
 
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Bill Hartman

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Thanks to everyone for your replies and thoughts on this. I went to bed early last night for a long day ahead so I'm just now reading. Yep, the truck hasn't had the problem since last weekend and I've been listening for it every time. I ordered a test kit from Blackstone and I think I'm gonna spring for the $28 to have the oil tested. All the maintenance, while under warranty, has been done at the same dealer so if it's the wrong oil I have them on two fronts - one, the engine knock, and two, they charged me $14.50 x 7 for the full synthetic oil. I know they will argue that I could have sent anything to be tested - but at least I'll know that much for myself and I'll at least have some backup documentation.

I did strongly consider having the dealer 200 miles away tear the engine down - but it was a hindsight 20/20 issue. At the time it was happening, it happened every time I started the vehicle without fail. I had no reason to believe it was going to stop before I got it home and actually I didn't even think it would get me home. But then when it stopped happening, I was trying to blow it up running 75 for 3 hours on a 100 degree day. That didn't work, so lesson learned there :) I am still running the crap out of it. I have two years left on the PT warranty so we'll see - I'm hoping it does it just once more. This is only my third truck since 1990, and the two prior (Chevys) are still running strong with a combined 350K miles. I take care of my vehicles. I would have never thought I'd be hoping that a vehicle engine would blow up before the warranty was out. This sucks.
 
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Bill Hartman

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Has anyone thought of possibly water in the gas? Could possibly be why you no longer here it.

I did fill up at a local Exxon station the day we left and it was raining. But I've never had an issue with that station's gas before, doesn't mean it couldn't have been a bad batch. However, it stopped making the noise before I filled up with new gas, so it was running what was already in the tank when the knock disappeared.

I will say I got a lot better mileage coming back on a fresh fill up then I did going down, by like +2 MPG average.
 
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Bill Hartman

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Kinda sounds like an exhaust leak

The dealer I took it to checked that, they said no. He told me that they have had issues with the exhaust manifold bolts - but according to them that wasn't the issue. They categorized the issue as internal engine.
 
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Bill Hartman

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That's a gas engine making that sound??? Did they forget to put oil in it???? Sounds like either lifter/cam slap/piston slap. BUT I am no mechanic. But if my motor was making sounds like that I would be beside myself, just saying... Does not sound like exhaust leak, but maybe a remote possibility...all IMHO.......

Indeed a gas engine and yes, it was completely full of oil - no low fluids, no warnings, no nothing other than noise.
 
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