loud diesel knock under no load?

[noelb]

When I first picked up my truck I had to drive it 700 miles home. The first thing I did was to find some fuel additive and top up the tank. On the way however I noticed that the engine would knock loudly under no load going down hill but would quiten right down under load up hill. I have driven approx 15,000 miles using fuel conditioner and the noise is considerably better but still threatens intermittantly around the city and on the highway. It has been suggested recently that it could be the injectors are dribbling. I have been tossing up whether to change the injectors. Has anyone else had a similar problem? OR does anyone else wish to comment? I have no idea how old the injectors are. The odometer is at 216,000 kms (133,000 miles).

[ronniejoe]

Louder Diesel noise under no-load is normal for these engines.

[Robyn]

Depending on the amount of miles on the squirters they could be getting flakey.
As RJ mentioned these engine will rattle more under no load but if its excessive a check of the nozzles would be in order.
My 94 is very nice now after the rebuild and it has a whole different sound than before. The other Sub is high mile and it has a few cylinders that are very noisy under light load.
Spray pattern and pop pressure all contribute to the noise level.
if you have one that is squirting off over in the corner they can get loud.
During the rebuild on the 94 I had the squirts checked and they all had low pop pressure and very poor pattern. If your rig is high mile it would be worth while getting the squirters checked. Most pump shops dont cahrge much to check them. if you are unsure just pull two off the drivers side (easy to get to) and have them checked. If they are poor replace the set.
A fresh set of squirters will really improve starting and mileage too not to mention helping reduce EGT under load. Bad squirts that are dumping instead of spraying a fine mist also contaminate the oil quicker too as you get poor burning of the fuel.
Hope this helps
Robyn