Mystery noise.. a loud one..

[Brianedwardss]

Welcome fellow burners! I'm usually the helper but today i'm the 'helpee'

I've got a loud noise in my truck that I'd like a second opinion on. In 7+ years of diesel service I've never heard this noise.

Okay, the basics. Truck starts first crank everyday, runs fine around town, no issues. BUT.. get on the highway, get up to 60 mph and in about 5 miles a loud noise appears. Its two noises in one. The most obvious noise is identicle as if you were running around without the air box on, sort of a very low pitch humming/popping.. At the same time, there is a high-pitched 'tick' similar to shaking a copper bb for an air gun inside a steel pipe. tick tick tick, you get it.

Now get off the highway, and at the light the whole truck is shaking and the tick/low pop is LOUD, loud enough people look at me. But two minutes off the highway and the noise is gone again. It only does it when the temp gauge is up to the N (which is hot on this truck). Its defintely coming from the driver side bank. I've removed the air box several times, and looking in while its popping there is alot of combustion gas flying around the intake. The box is on TIGHT and it still does it so eliminate that.

Here's what I've done the last two weeks just to see:

-Installed rebuilt IP
-Verified the 'Y's were lined up on the cam/IP gears
-Installed 8 ZD-9 plugs
-Installed 8 reman injectors from 'Pensacola Diesel' (craigslist find ;p)
-Injector return kit, plus new return hose to the top-front of IP
-Advanced/retarded the timing both ways, noise is WAY worse when retarded
-Fuel Filter
-Oil change
-Air Filter

My personal guess is maybe an intake valve sticking/leaking since its the intake that has all the noise, but I'd LOVE to be proved wrong, maybe... I made a video that I'm uploading to youtube as well.

Thanks in advance

 

[plywood]

I bet if you just took the valve covers off you could see where the culprit is.

Maybe a bad rocker or something and the ticking is the lifter or pushrod floating.

Maybe some thicker oil would be diagnostic if a lifter is failing.

 

[Brianedwardss]

Ok, added a quart of the thick Lucas, drove it, same issue. Removed valve cover, ran the engine.. nothing obvious. I removed the rockers and pushrods, no flatspots. Probably a bad valve.

 

[plywood]

Yeah, I don't know if you know Russ, (type4), but he recently said a good portion of the bad IDIs in junkyards around have bad valves, or valve guides or seat, don't remember which, but in any case I agree with what your thinking.

I thought you might see where a valve seal was burnt, but if it hasn't been going on long then maybe not.