Here is the deal. Engine runs great, little loss of economy lately. Oil pressure has dropped slightly, but well above the half way mark on the gage. Think that is only normal wear of 100,000 miles. NO blowby problem, very light.

Most noticable on pull off, loaded or empty, a distinct knock or burned valve sound. Do not hear it at full throttle or idle. At cruise it is there with very slight throttle.

I thought it was injectors, changed them. Was quiet at first but with a load it is back the same.

At this point I honestly have no idea what it is.

 

Uggghh. You just can't seem to get a break can ya. I'm sorry to hear about this happening to your new engine. I hope you get it figured out.

 

Aw crap.

Bill did you break a mirror when you tripped over a salt bucket trying to avoid the black cat underfoot while walking under a ladder?

You said in your other thread that you reset the valves when you changed injectors, were any of them off by much?

 

Dang Bill, you are having a heck of a time here lately. Sorry, but I have no insight that would help.

 

Valves were all on as they were set. Spun all the pushrods all looked straight. Pulling the injectors, none seemed to very from normal on the engine side. Engine is spottlessly clean inside. Visually the valve springs all looked good.

 

just out of curiousity - how can you hear a knock over the noise of the motor itself?

 

I guess it must be loud enough, ya think?

 

Ok, took it to the friendly Cummins dealer today to get their opinion on it. He pretty much had the same impression as I did and another mechanic there also felt that it probably is a burned intake valve.

He said that I may still have the injector problem, they have had a bunch of them where they replaced the injectors and one was lazy causing this type of problem.

He agreed, no blowby, probably not a piston.

Noise does not sound like a rod and normal oil pressure.

So I am getting the original injectors flow tested. I will remove the intake and see if the noise sounds like an intake blowing back.

Till then I am chancing it and running it.

I expect to have to pull the head, I have two of them here to replace it. Now hope the valve if that is the problem, does not drop and I start all over.....

It feels like a slight miss along with the noise, so it will probably be a valve or injector.

I will be relying on my good luck..... thats a joke guys

 

do a leak down test before u pull the head may save some work

 

Bill do you believe in numerology or astrology? Maybe you need to change your name. It's all in the numbers. You got to shake that Murphy off some how.

I was skeptical but now I believe there must be something to that. The daughter got married 5yrs ago which changed her last name & has had nothing but bad luck since.

Good luck Bill hope you get it resolved. We'll say a little prayer for you to rid your life of those demons.