Ok. I had my truck checked out at my local shop. They did buzz test, but never pulled injectors. I had them change oil, fuel filter and still has a knock. I am trying to figure out how to post the video I took today so some can listen. Will hopefully be up this evening. So it doesn't knock right at startup. But once it warms and I get going on the throttle it knocks over the idle. Then at high speeds it lets up when I get off the fuel. I can manipulate it with the pedal. This truck I just purchased about a month ago. Have put 2000 miles on it. Has 202,000 on her. She accelerates well and shifts fine. Can't figure why this mech. Didn't get any deeper into it but didn't offer much. I hope to take it to another mech this week to really diagnose. Any input would be great. I am new to the forum but have spent countless hours learning about the 7.3. Have seen some scary stuff and some stuff I can deal with regarding knocks on these diesels. I will try to get the vid up soon. Might help point me in the right direction.

 

I could not get the forum site to upload the video, but have put it on you tube. If anybody is willing to search the video My you tube is Michael Clark and if you search. Title is 2001 7.3 engine knock. Is this rod or injector sound? Please tell me it is not rods or lifters.

 

Where are you located? Someone might be close and willing to listen.

 

Ok here we go 02 7.3 330000. Miles has noise sound like ex leak,rock tap,or knock all depends on where u r in the throttle
Did compression test 400 psi across the board now here's the kicker if u mat it to the floor
The fuel pump don't keep up when it hit about 10 psi sound go away just driving has 80 psi
N u can see the fuel pressure gauge jump with the sound

 

Is this it?

 

I am in eastern nc. Outer banks. Basically live on a little spit of sand we call an island. My work carries me to parts of tidewater Virginia. Anybody near here willing to take a gander?

 

Maybe start your own thread, two problems will get confusing.

 

Yes that is it. The muffled sound in the beginning is just windy conditions. Tried to move about the truck to get best sound. What do you think?

 

I have the same sound on my 03 7.3 i just purchased with 114k miles.

I've been lead to believe that is the #8 crackle, air getting into the fuel system and being pushed out the injector.

I just bought clay's FRX and going to do the hutch/harpoon mod. I REALLY hope it is not a problem with the engine itself. Mine only does it when warm after driving a while.

 

It gets the knock when it warms up, and gets down the road. It can be manipulated as I ease off the pedal. And when it coasts. But then kicks back in at the lights and acceleration. And is constant on highways. Otherwise the truck operates and handles great. Just hope it isn't something in the lower end. I want to get a good diesel guy to get in the valves covers and diagnose it. Anybody out there with some input???? Maybe somebody can ease my mind... Might actually get some sleep if this thing unites down. It's is a bucket truck that I truly cannot afford to $?#@ the bed.

 

Certainly sounds like an injector issue to me. Get the truck up to speed at fifty five at operating temp, Let off and coast, if the noise goes away its injector related in my opinion. Injection stops under that type of condition. Lifters and pushrods are possible but highly unlikely in my opinion. With your mileage I'd say it's either number 8 injector cackle, or an injector beginning to fail. It doesn't take much to pull a valve cover yourself and by buying a mechanics stethoscope it'd be easy to identify the source of your noise.

Low fuel pressure destroys injectors and certainly makes them cackle much louder then usually. Low fuel pressure forces the intensifier piston father down in the injector causing issues so check your fuel pressure, there's a tet port on the back side of your fuel bowl. If its low then drop that fuel tank, eliminate that mesh filter in the tank and install an inline filter and be done with it.

 

I was hoping for the injector. I will look at the fuel bowl. And check fuel pressure. Thanks for input. Should injectors be replaced one at a time? Or all? Should I do glow plugs as well? I am ordering a new relay this week. Have had to plug in lately.

 

With your amount of miles you probably could have at least one injector giving you fits. usually the noise gets better with oil temperature raising, the fact that yours gets worse makes me think fuel pressure. A cheap test is to pull the cap off of your fuel bowl, pull the fuel filter and drain the fuel bowl. On the back of the fuel bowl, left hand side, if your facing the truck, on the very back is a yellow lever, that opens the drain. At the bottom of the fuel bowl in the back there is a 3/8 tube I believe, find a piece of 3/8 rubber tubing to hook to it to drain your diesel fuel into. Could take a peak at that and look at your fuel sample?

If it ends up being an injector, and you only want one, any parts store should be able to order just one, depending on your budget,and what you want do do with the truck, I'd recommend replacing all eight. You should buy your parts through this sites supporters as they keep this site going and not only have the best customer service you could ask for, but much better prices then the average parts store. In my opinion. Anyway, you should do the glow plugs while your under there and do the fifty cent mod and grind down a quarter and fix each valve cover harness. At the beginning of this forum is the tech folder and there is a tremendous amount of good information in there about your 7.3.

I hope I helped and I hope you get your truck sounding and running the way you want.

 

I have the same noise but only have 115k on my truck. Should I look at replacing an injector too? Seems early in their life for that....

 

No, start with checking your fuel pressure. Theirs links in the tech folder to assist you there. Theirs tons of things that make that noise in this engine. And then again maybe it's just the nature of the beast. Mine made that noise too and it ended up being low fuel pressure at idle. An injector is worst case scenario..