Engine/Transmission (1998.5 - 2002) long-standing engine knock when warm

[jzaremski]

I need to bounce this off of you guys. My truck is a 2000, 5-speed, standard cummins (235/460). I've had a minor knock ever since the truck hit 200 miles (no typo, two hundred). It now has 71000. It doesn't sound like a typical bottom-end problem, more like one cylinder is louder than the others, but here's what I know so far:



- Doesn't occur when cold, freshly started.

- Starts making itself heard after being driven a few miles.

- loudest when approaching operating temperature

- does not use any oil (and I mean near zero oil consumption between changes)

- does not smoke

- oil pressure is fine (if the dash gauge is to be believed)

- injectors are not the cause



So far, three trips to the dealer (two different dealers) got me "No Abnormal Noise found" diagnoses. I'm hoping to convince a Cummins Michigan to take a stab at a diagnosis, but they're usually unwilling to look at pickups, especially those still under engine warranty.



The last thing I need is to be told that there's no problem, then find out there actually is one at 101,000 miles

 

[FFutch]

What R.P.M....

... mine has a faint knocking noise at about 19-2100. People here say it's the V. P. -44. I've got 66k on mine and no oil usage,ect. either... . Doug

 

[jzaremski]

don't know if that's it, the pump was replaced at around 34,000 due to the failed lift pump, and it didn't sound any different afterwards.

 

[Motorhead]

Sometimes an injector can make more noise firing off than the others. My Wifes MBZ Turbo Wagon does this and It has 203,000mi on it. The VW diesels would sound like a bad rod knock when they had a bad injector

 

[johnrv4]

Check out this thread

I don't know if this will help you, but check this thread out:https://www.turbodieselregister.com/forums/showthread.php?s=&threadid=49988&highlight=engine+knock

 

[Old Man]

Knock

There is a TSB out now for the T-stat. Later.

 

[jzaremski]

mine knocks at idle, it's not apparent at speed. Guess I left that part out



Monday I'll schedule an appointment with the local dealer, maybe while I'm at work I'll make a recording and post it.



If you've ever heard a Powerstroke's idle "cackle" then you'll have an idea of what I mean. but mine's not quite that "sharp".

there's a recording of one on

Jason's site.

 

[illflem]

I'd have an oil analysis done and see if it's pointing towards abnormal bearing wear then take the results to the dealer

 

[Alan Reagan]

Sometimes you won't get the knock when a diesel is cold because of the retarded timing causing combustion well after TDC. As the engine warms, the combustion occurs at the designed time and you can/will get a diesel knock.