The diesel engine on my CASE 4803 frontend loader runs incredible rough at idle (750 rpm). In fact the rough idle is so bad that the whole loader vibrates and consequently snapped an exhaust manifold bolt to the muffler. My quick fix is to raise the idle up to 900 rpm where the engine vibration smoothes out. By raising the idle speed, am I missing/ignoring a bigger problem with the diesel engine? Mike from Cleveland
you mean like a burnt valve or a bad injector?
Check your engine mounts as well
I would send the injectors out and have them tested/rebuilt.
Success! The diesel engine runs smooth at idle, 750 rpm. I removed the diesel injectors and had them cleaned and serviced at York Diesel of Medina, Ohio. Also, I used a gun cleaning kit to clean out the injector ports. The cleaning rods are made of brass and the bore brushes are made of copper wire so I really can't starch the inside of the injector port. I rotated the brush in a clockwise direction and used a .20 gauge shot gun wire brush for the injector port and a .30 cal wire brush for the cylinder hole. The next step I used gun cleaning cloth patches to remove carbon deposits and finished up with vacuuming the injector ports with a narrow and long tube. I made sure the cloth patches did not fall off and into the cylinder. Thanks for everyone's suggestions. Case closed.