warp2diesel
Full Access Member
No code on bad glow plug strange & weird
I had the symptoms of a bad glow plug, rough start, with no codes being generated.
I checked the glow plugs with a VOM and one of them #3 acted like a capacitor when tested for the resistance.
Like a capacitor the resistance reading would show on the display for an instant and then indicate an open circuit.
I replaced all 4 glow plugs with new Bosch spares and treated them, very very carefully. Two spun out with my fingers and the other two I screwed them in and out with WD-40 on the threads until I could spin them out by hand. Since I heard that one of the causes of breakage is caused by doing the job with a cold engine. I plugged in my block heater for 4 hours, drove a little until the engine was half warmed up, plugged the block heater back in to keep the head warm. Made it better for my hands working outside in the mid 20s (F).
When I got the new ones in, I checked the resistance and all four checked out, then I reassembled.
After I was done, I retested the bad #3 glow plug and it still acted like a capacitor.
I would bet that some (not all) of the broken glow plugs are due to some Techs using air ratchets or other impact tools to get them out when stuck. Some Techs use air ratchets to remove Spark Plugs , why not on glow plugs.
Not on my engine.
This morning,a normal start, no more shake for the first few seconds.
I had the symptoms of a bad glow plug, rough start, with no codes being generated.
I checked the glow plugs with a VOM and one of them #3 acted like a capacitor when tested for the resistance.
Like a capacitor the resistance reading would show on the display for an instant and then indicate an open circuit.
I replaced all 4 glow plugs with new Bosch spares and treated them, very very carefully. Two spun out with my fingers and the other two I screwed them in and out with WD-40 on the threads until I could spin them out by hand. Since I heard that one of the causes of breakage is caused by doing the job with a cold engine. I plugged in my block heater for 4 hours, drove a little until the engine was half warmed up, plugged the block heater back in to keep the head warm. Made it better for my hands working outside in the mid 20s (F).
When I got the new ones in, I checked the resistance and all four checked out, then I reassembled.
After I was done, I retested the bad #3 glow plug and it still acted like a capacitor.
I would bet that some (not all) of the broken glow plugs are due to some Techs using air ratchets or other impact tools to get them out when stuck. Some Techs use air ratchets to remove Spark Plugs , why not on glow plugs.
Not on my engine.
This morning,a normal start, no more shake for the first few seconds.
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