I have an 03 LB7 with 147k km. Yesterday morning in traffic I noticed a fairly loud knock. I shut it off and waited 5 minutes, restarted it and the knock is gone. 10-15 seconds later it comes back. I changed the fuel filter to no avail. This morning same thing normal when I first start it up and then it starts knocking. Any ideas?

how does the oil, and oil pressure look?

Oil looks good. Pressure is normal.

I was told my knock after the engine warms up is the "typewriter click."

I have an 03 LB7 with 147k km. Yesterday morning in traffic I noticed a fairly loud knock. I shut it off and waited 5 minutes, restarted it and the knock is gone. 10-15 seconds later it comes back. I changed the fuel filter to no avail. This morning same thing normal when I first start it up and then it starts knocking. Any ideas?

check your block, if not that, piston rings.

It's not the typewriter noise. I'm familiar with that.

What should I be checking for on the block?

Look in your rear view mirror and see if it's letting out white or black smoke when it knocks - if so it's likely injectors - mine did that when under a load.

Disconnect the jiuce/***. then give it a try.

Hooked up a scan tool and turned off injectors 1 by 1. Turns out injector number 8 is the problem. Just had them all replaced 5 months ago.

Thanks for the suggestions.

I was just thinking....how does shutting off an injector make the knock quit? Is it firing out of time or too much or ?

So.... Dealer diagnosed and says it's something internal. Broke ring or piston? I thought maybe an injector stuck open and caused damage but the Tech says balance rates are within spec. Any ideas if there is anything I can do to find out if this is injector related?

Thanks.

I was told my knock after the engine warms up is the "typewriter click."
what is "the typewriter click" noise???

So.... Dealer diagnosed and says it's something internal. Broke ring or piston? I thought maybe an injector stuck open and caused damage but the Tech says balance rates are within spec. Any ideas if there is anything I can do to find out if this is injector related?

Thanks.


If it was something internal...wouldn't it knock all the time? From what I understand, your problem is intermittent correct? I had a weird knocking noise on my LB7 that sounded like a hammer was hitting the engine block and it ended up being the belt tensioner causing the noise. If your oil looks good (no fuel, contamination, etc), balance rates check out, and your fuel mileage is still good, it could be something more simple....

If it was something internal...wouldn't it knock all the time? From what I understand, your problem is intermittent correct? I had a weird knocking noise on my LB7 that sounded like a hammer was hitting the engine block and it ended up being the belt tensioner causing the noise. If your oil looks good (no fuel, contamination, etc), balance rates check out, and your fuel mileage is still good, it could be something more simple....
I thought the same thing that it would knock all the time. I'm going to get it back from the dealer and look a little closer.