under 100k high pitched knocking?

[stereojoey]

i have a 98 6.5 dually with only 95k miles on it. im crusin down the highway 3 weeks ago at about 60-65mph and out of no where is this loud high pitch knocking noise. i took it to the local dealership for a diag of the problem(this is my first diesel i ever owned) dealership said it was something deep inside the motor like a rod bearing or something. well a good friend of my dads listened to it and said it was most likly an injector issue. he reccommended that i have the injectors tested. so i got the first 4 out easy but the turbo side is not so easy. from what i can tell i have to remov the turbo. but the damn nuts are on the bottom of the turbo...why? how the crap do you get them off with out pullin the motor? remove the fender liner and try that route? does it even sound like an injector issue to yall or the injector pump? i read that that motor has injector pump issues or something to that effect. i can do most of the work to it myself but with this being my first diesel i got no clue where to even start. thanks for you guys help.

[hraney]

A rod or main should be a low, deep sounding knock. Sounds like it could be an injector to me. Lots easier to check out than the Mains, too. And yes, it is best to remove the fender liner to get to the injectors under the turbo. The injector pump "issues" mostly deal w/ the electronics failing due to heat on the drive-by-wire system GM setup on the pump. I am lucky enough to have a Stanadyne dealer/repair shop pretty local to me. I have yet to meet an actual diesel mechanic at any of the GM dealerships around here.

[3bals]

I had a simular noise in my engine a couple of years ago. It turned out to be the vaccum pump. The guy that found the problem, took a wooden dowel long enough to reach the pump. He placed it on the pump housing and put the other end up to his ear. (be careful of the belt and fan!) You could hear the clicking. I replaced the pump and all was fine.

Jody

[Gottado]

I am in no way an expert but mine was making a noise that sounded like I was about to lose a rod thru the oil pan. My neighbor who drives semi's heard it and told me it was water in the fuel. He recommended and I now use Lucus Upper Cylinder Lube and haven't heard it again (almost 2 years now).

[DragNasty]

My dad drives a semi too and we use lucus in all our trucks.