I have a noise that started aboud 1k miles ago. It sounds like a rod knock at times, then sometimes it sounds like fuel knock on a cylinder. Im pretty shure its at crank speed. It wont do it when cold-cold, but it will before temp gauge moves. It will never do it on decell(engine braking), at idle its noticable sometimes, at steddy crusing speeds some times I wonder if shes gona blow. If I snap the throttle w/no load thers no clatter like I would think a rod would do. Just as I start to think the worst, It goes away, but comes back at diffrent noise levels.
I have tried to issolate witch cylinder it is, and I cant tell. Not only does it come and go, but you cant here it when your ontop of the engine or below it. If i crack each line one at a time its still there each time. I pop tested all injectors, all but one is between 315-340 bar, one at 270. I know spec is 300 but will this cause the noise? Ill blame my not so smooth idle on this. Also with no load she smells like raw fuel at full throttle, w/some fuel smoke. Im gona blame injectors again.
I just dont want to throw injectors in it, and have to yank the engine with no $ left. my compression is between 330 and 360 across all six, and oil pressure is 30 psi at low idle warmed up. I changed fuel filters and added fuel lube, and same old-same old. Im looking at DDP stage two's for injectors, any suggestions?
For the future iI plan on gauges,4'' exhaust,air fliter, fuel plate, and maybe a hx40 that I already have. not shure on what fuel plate to choose for my daily driver(100 miles a day). Thanks for any info!

 

Next time you change the oil, unless you want to do it now as a preventative measure, look to see if there is a silverish-white substance floating on the surface. That would be bearing material and is a good indicator of a bearing going...or gone. With the sound being intermittent, it's tough for me to say that a rod or main bearing is going. They're pretty good at letting you know you got a problem in the worse way possible. There's a possibility it could be valve adjustment that's out of wack. I've seen that sound come and go on gas engines on rare occations, but, I've never personally heard it happening on a diesel. You are right, it's tough to listen for unusual sounds on these 12 valves...they're so freaking noisy to begin with. If you do get it to happen again while it's sitting there, get a long metal rod, or long screw driver, and touch one end to parts of the engine with your ear at the other end listening. Trust me, it works. Just be carefull what you put on...spinning things can cause pain, but, that's just common sence.

 

I did drain oil and cut open the filter, and nada. I also used a stethascope, cant pin point to cyl. but it does seem louder at the rear. pretty shure im gonna try new sticks. not shure if i should spend 5 bills on some ddp's or drop 3 on some 300"s. any info on that?

 

Unless you just want new sticks I cant balme you if you do. You may want to try some stanadyne fuel treatment you will have to go to a pump shop to get it I had a really bad injector knock on my 97 called cummins they suggested trying it. I bought some and within 30 miles the knock was gone never to return. Its alittle pricey but cheaper than new sticks.

 

Is there any blow by from the dipstick and vent hose?

 

It the input shaft brg for the tranny thats pressed into the end of the crank where your flywheel is located. Almost positive, happened to me about 17 years ago on a 2wd cheby with a manual tranny drove me nuts. I rebuilt the whole tranny for nothing, ended up being a simple $12 fix.

 

Just stabbing in the dark here, but have you taken the inspection cover off to see if there if there is something coming loose in the clutch/flywheel area?

 

on the injector topic i would do 300's with 191 DV's. Ive done alot of research on this topic and someone said they did 300's and didnt notice TOO much of a difference but went to laser cuts and it really gave the truck a goose. Even said the laser cuts were too much for a daily driver so i would do 191 and 300's (you can get both for about $525) and you can control the exact amount of fuel pretty well with the fuel plate. just my $.02

 

To answer some questions, i have -0- blowby. From my 350 psi comp test i think she's healthy up top. First thing i did went i got the truck was install a sb clutch, w/new piliot and throw out bearings. Funny Troy should mention stanadyne treatment, I had some left over from a job(5 oz.), i put in what i had, and it did make a idle improvment, but still the noise. I dont know, I'll runer till somethin shows up.

 

What kind of HP can you get out of 300's?

 

ah ha,
This may sound wierd, but it was the extremly low sulfer fuel. dont know why, or if any body else has experienced this. I just started putting two and two together and took notice where I got my fuel, and the tag on the pump. After a fill up with low sulfer it wasent so bad, then with diesel kleen it was gone. went back to extremly low sulfer and no diesel kleen for a test and wala knock, knock. needless to say no more extreme low sulfer and more diesel kleen. yea!

 

The fuel issue can be solved by adding some wally world 2 stroke mix. Make sure it's the blue bottle with the TCW-3. It has additives that prevent ash deposits. I run 1 quart to a full tank of fuel.