6.2 disel clatter / rattle.

[sermis]

1990 M998 6.2. Truck was running great and then from time to time while driving it would start a loud diesel clatter / rattle and then go back to normal. Now it has the clatter is all the time. It's not like a rod knock but a clatter. Almost like when using starting fluid to start one. Also notice the cooling fan is staying locked now even when cold. Any ideas?
Cant get the audio files to load.

 

[Katavic918]

The making noise and then going back to normal is the part that has me miffed. How's your oil pressure? Has it's running pressure changed from when it didn't make the noise? As for the fan, search for trouble shooting procedures. Its pretty straight forward to test them. It did it with mine. Good luck.

 

[sermis]

Oil pressure doesn't change and the running pressure is very good.
I think the fan is a sensor issue maybe.

 

[Videris]

1990 M998 6.2. Truck was running great and then from time to time while driving it would start a loud diesel clatter / rattle and then go back to normal. Now it has the clatter is all the time. It's not like a rod knock but a clatter. Almost like when using starting fluid to start one. Also notice the cooling fan is staying locked now even when cold. Any ideas?
Cant get the audio files to load.

http://www.dieselplace.com/forum/63...6038-super-loud-engine-rattling-knocking.html

could be worse.

 

[sermis]

Well that is a knock, mine is more of a clatter.

 

[Katavic918]

Could the fan be making the noise?

 

[Barrman]

Unplug the advance wire from the IP. Take it for a drive and see if that helps. If so, then the sensor on the passenger side rear head could be faulty. I get back to my class and your other truck Tuesday. I have one of those sensors there if that is the problem.

If that doesn't change anything then it will probably come down to the IP. You know where to go for that.

 

[springbok]

Injectors.
Had the same thing..
While running crack the line to each injector to find the one making the noise.
Also try running injector cleaner just to see if it helps.