Powerstroke sound

[RobertN]

I have noticed that many Powerstrokes, when outfitted with a big exhaust, seem to make a sputtering sound. I notice it when my neighbors friend comes by; we have a small hill leading up to our street. Friend from the fire station, his truck does it too. I have noticed it from most Powerstrokes.

They seem to sound smooth at idle, but when accelerating or under load, it sounds like a gas V8 that is missing on a couple cylinders; I could just imagine a 460 with two bad plugs.

I have driven various trucks with the Powerstroke. They make plenty of power, and seem to run smooth. The two trucks I mention in particular run great; my fire buddy tows a 32' 5th wheel no problem.

I have not heard a Duramax with an opened up exhaust to notice. My Cummins has a 4" exhaust; it sounds smooth, as do others I hear.

Is it just the firing order that makes for that sound? I mean, they feel smoother than they sound when I have driven them.

 

[Raspy]

I've noticed that too. They just sound sick (not in a good way). Not that I really care, as I'd never have one anyway.

 

[Dmace]

The problem is that older Powerstroke only has 2 valves per cylinder vs the Cummins and Duramax that have 4 valves per cylinder. It makes that sputtering sound because of the blow-by and valve overlap that occurs with 2 valves vs. 4. You only hear it more pronounced with an open exhaust.
The newer 6.0l, 6,4l, and 6.7l Powerstroke's are 4 valves per cylinder.

Are you hearing this on newer Powerstroke's too?

 

[moship]

robertN,

Starting in 1999 with the new 7.3 Powerstroke they have suffered from what most will term "Cackle". At certain RPM's it is more pronounced, but it does sound horrible and can not be good. Back during the introduction of the engine there were a few people who were really trying to come up with a remedy. There was a guy who spent a considerable amount of his own money purchasing the high speed pressure transducers to document what was going on in cylinders 7 & 8. Unfortunately just as he was making significant progress and in discussion with Ford, he succumbed to cancer. Basically it is a function of the pressure spikes occurring in the fuel system and when the next injector fires. At certain times they become starved for fuel. It is not uncommon for the 7 & 8 cylinders to show a higher incidence of issues or failures compared to the others.

Of course Ford denied there was a problem and then started to prescreen the injectors they put into cylinder 8 calling them Long Lead injectors and reprogrammed the computer. There was a recall on this in the early years. It was nothing more than a band-aid to compensate for poor function.

To remedy the problem a number of people including myself altered the fuel system by redirecting the fuel flow direction and turning it into a returned system. Turning up the fuel pressure also helps.

Of course the dealer will tell you this is 渡ormal? but being normal does not make it right.

 

[JESSE1]

Cackle and Idle Knock were big concerns back around '99. I remember the guy who was working on the injectors, never knew what happened to him, just suddenly disappeared.

 

[moship]

The guy I'm thinking about went by the forum name TexasTownCar. There was another guy who claimed to have a solution, but was super secretive about what he was doing. I can not remember his name right now, but in the end nothing ever materialized.

 

[RobertN]

Have not noted a year. Some seem more pronounced, so maybe it is the older ones.

Just never asked before.

Are you hearing this on newer Powerstroke's too?

 

[JESSE1]

I remember TTC, but the other guy was Kim Lux. The more people talked about the problem, the more they heard it. I never noticed either of the noises they were talking about.

 

[MtnViewRanch]

I have noticed this also, but not in mine and it is 10 years old. My one neighbors sounds fine and his is an 02, but another neighbors 02 started to sound like what your describing about 1 year after he put a chip and all the Banks stuff on it. Do you guys think that these chips may have something to do with this sound and what is going on in the engine? Neither my truck which is an 01 or the neighbors 02 that sounds fine have chips in them.

 

[Diamondpilot]

Both of my 6L's have big exhaust on them and did not make any weird noises till I put MAC air filter kits on them. The kit has a K&N style air filter and a chrome intake tube. The factory intake setup had some kind of a muffler in it. This led to a restriction but did its job to quiet it up, especially under deceleration.

The noise I have noticed on my trucks is like a jake brake noise. I feel it comes from the variable vane turbo the 6L and later Fords used.

Chris