My Glow Plug Experience on L3650GST

[MichKubota]

Thought I would share my recent experience with glow plugs in L3650GST.

On Tuesday the temperature was about 12F and wanted to do a little work with tractor. Gave glow plugs about 30 seconds before starting tractor. Tractor started OK but was a little rough for about 10 to 15 seconds then it smoothed out. Did my work and brought tractor into garage and parked. Got off tractor and noticed some fluid had dripped on vertical exhaust. Removed engine side panel and also noted a some fluid had come from exhaust manifold bolt. I guessed that when I started tractor all cylinders were not firing and diesel fuel was thrown from exhaust and manifold.

Suspected glow plugs had not all fired at startup. Let engine sit for 6 hours to get cold. Turned on glow plugs for 30 seconds and felt each one to see if they were getting warm. Only 2 of the 4 plugs were warm.

Next day removed daisy chain of wires on glow plugs. Checked resistance of each plug and all were between of 0.7 to 1.0 ohms. At this low resistance level, ohm meter may not be real accurate. But I believed all plugs were good.

Next the wires used to daisy chain the plugs together were checked. To my amazement they were aluminum and showed oxidation where they connect to the plugs.

Replaced the 3 aluminum wires used to daisy chain the plugs with one continuous solid copper (10awg) wire. Changed glow plug lead wire from end plug to one of the two middle plugs (to better distribute the current load).

Turned on glow plugs for 30 seconds and they all seemed warm to the touch. Used a clamp on DC amp meter on lead wire and current was over 40amps when first turning on glow plugs. It settled down to about 40amps after 10 seconds. Wish I had measured current before starting this job.

All plugs seem to be firing correctly now and engine runs smoother from the beginning. Not seeing any fluid from exhaust pipe or manifold.

 

[Shimon]

Good troubleshooting and repair. Thanks for sharing.

 

[Baby Grand]

They really use aluminum wiring? I'm shocked. I'll have to check mine next time I do maintenance. BTW - great troubleshooting/thinking out loud write up. Very helpful for future reference.
-Jim

 

[MichKubota]

Not positive the original glow plug daisy chain wire was aluminum. Put here is what was found:

1. It is silver or aluminum color.
2. It is very soft material.
3. Magnet will not stick to it.
4. The original three daisy chain pieces were about half the weight of the copper wire even though the copper wire was 0.10 diameter and the (aluminum) was about 0.14 diameter.
5. It looked oxidized (white powder on terminals).

If someone knows a good way to verify if it is aluminum wire, I would appreciate the feedback. It's hard for me to believe it is aluminum.

Side thought-
Even though this is ugly tractor (it has been left outside most of its life) the new copper wire looks bad. Works much better but looks bad. When weather gets better the copper wire will get replaced with piece of copper buss bar. It bothers me to do a job that looks amateurish or held together with baling wire.