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troubleshooting e320CDI glow plug system

Old Nov 21, 2022 | 10:53 AM
  #1  
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troubleshooting e320CDI glow plug system

260K trouble free miles on my e320.....last of the cast iron blocks. Got to love the simplicity vs DEF tanks and heaters. Glow plug light staying on after start up so I replaced all the glow plugs with Beru units (except #6 which I could not get out). Still hard starting on cold days....replaced the glow plug controller thinking that would be the likely culprit. That was fun replacing the controller but successfully made the switch. Still not functioning. Does this system have a fuse or circuit breaker? Assuming the single large wire in is the supply. Is that always on with the ignition switch?
Suggestions on next steps....30F this morning.
thanks for any troubleshooting tips.

Last edited by ekm; Nov 21, 2022 at 11:00 AM.
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Old Nov 21, 2022 | 06:02 PM
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Love my DPF and DEF equipped OM651, who starts in negative temperatures on 1st turn
Not familiar with your engine, but GP fuse usually is part of controller?
Do you have a scanner, who can test GP? If not, I would hook up small light controller to 1 of them, so you'd be able to check what is going on.
Also checking rail pressure would be advised.
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Old Nov 29, 2022 | 12:47 PM
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There is 12V going to the glow plug controller...its on all the time (not switched from ignition switch).

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Old Nov 29, 2022 | 02:08 PM
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yes, with scanner, it will tell you which glow plug is bad. Or you can check with multimeter without removing the glow plug. Good glow plug is about 1.5Ohm and bad glowplug is about >20kOhms.
Also make sure the replacement glow plug is a 5V unit. Beru p/n:0 100 266 042.
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Old Nov 30, 2022 | 10:17 AM
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Originally Posted by sand8
yes, with scanner, it will tell you which glow plug is bad. Or you can check with multimeter without removing the glow plug. Good glow plug is about 1.5Ohm and bad glowplug is about >20kOhms.
Also make sure the replacement glow plug is a 5V unit. Beru p/n:0 100 266 042.
what are you using for a scanner??
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Old Nov 30, 2022 | 10:25 AM
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Originally Posted by sand8
yes, with scanner, it will tell you which glow plug is bad. Or you can check with multimeter without removing the glow plug. Good glow plug is about 1.5Ohm and bad glowplug is about >20kOhms.
Also make sure the replacement glow plug is a 5V unit. Beru p/n:0 100 266 042.
I replaced all the glow plugs with the 5V Beru's prior to replacing the controller. I could not remove #6 and have penetrating oil in that hole.
Thoughts on next steps?
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Old Nov 30, 2022 | 10:51 AM
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Originally Posted by ekm
I replaced all the glow plugs with the 5V Beru's prior to replacing the controller. I could not remove #6 and have penetrating oil in that hole.
Thoughts on next steps?
I would use Valvoline #602333 carb and throttle body cleaner, available at Menards $3.29 a can. Amazon wants $17 a can. I haven’t pulled any glow plugs yet but 602333 works super well on black death, I had two injectors in a very bad state, including wiring and piping, dissolved the tar with ease.


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Old Nov 30, 2022 | 01:21 PM
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"what are you using for a scanner??"

Any scanner that support OBD2 will tell which glow plug is bad.
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Old Nov 30, 2022 | 01:24 PM
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Originally Posted by ekm
I replaced all the glow plugs with the 5V Beru's prior to replacing the controller. I could not remove #6 and have penetrating oil in that hole.
Thoughts on next steps?
I replaced when the engine it hot. Just make sure not to force it. I think the torque spec is 15Nm.
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Old Nov 30, 2022 | 04:41 PM
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1922 Ford Model T / no OBD
And again

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Old Feb 15, 2023 | 06:15 PM
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Winter is almost over....only drove it when it was above freezing. So if I connect the glow plug wiring to a multi meter, it should show voltage (5volts)?
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Old Feb 16, 2023 | 12:55 PM
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You check the glow plug individually with multimeter, not the wiring.
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