Tractor Repair: Kabota L2900 Glow Plug, knurled knobs, glow plugs

Question
How do i troubleshoot the glow plug? How do i idenify the plug. Thanks

Answer
Hello,

  Testing glow plugs is fairly easy.  First, use a test light or voltmeter to make sure there is power actually getting to the plugs when the switch is in the preheat position.  If not, it could be a fuse, the switch, and also some machines have a glow plug relay.  If there is power, test the continuity between the center wire connection on the plug and ground. (the cylinder head)   If there's no continuity, you already know the plug is burned out.  If there is continuity, the plug is probably good, but I have had 1 situation where the results of this test were good, but the plug still did not get hot.  For this reason, I no longer rely only on this test.  I also remove each plug, ground the body of the plug and apply 12 volts to the wire connection.  The tip of the plug should get too hot to touch instantly.  If it only gets warm, replace it.  Test all the plugs this way.  Even if only 1 of them is bad, the engine will be harder to start.

  I'm not quite sure what you mean by how to identify the glow plugs, so forgive me if I get too basic.  I'm not trying to insult your intelligence, I simply don't know your level of mechanical knowledge or ability.  It's also hard to explain without being able to show you.  On top of the engine there will some small round knurled knobs with a screwdriver slot offset from the center of each knob.  There will be a wire leading up to the rear plug, but from there Kubota uses solid metal rods instead of wires to connect between each plug.  Remove the knobs, remove the rods between the glow plugs, and unscrew the glow plugs from the engine.

            Hope this helps.   Good luck.

                     Arnie