Glow plug fault
Thread Starter
Member
Joined: Aug 2017
Posts: 96
Likes: 13
From: Waterloo, Ontario
2005 E320 CDI,
Glow plug fault
Hi All, I have an 2005 E320 CDI,
Just checked a CEL with Icarsoft MB11 reader and it shows a P0675 fault, Cylinder 5 glow plug circuit open.
When I start the car the glow plug light lights up, turns off in a few seconds, then when the engine is running the glow plug light in dash comes back on and stays on for 60 seconds, then turns off.
This happens always when I start up the car for the first time on any given day. After the car is warm and subsequent starts throughout the day, the glow plug light doesn't come on for the extra 60 seconds.
In the meantime does anyone know what the issue could be? Replace glow plug on cylinder 5? Or something else connected to glow plug, a relay perhaps?
Do cylinder numbers go from front of vehicle rearwards? If this is the case then 2nd glow plug nearest cabin is the one in question. Or is it the 2nd one from front of vehicle?
Not very well versed in electrical fixes, but with some guidance from all you experts, I can work it out.
Thanks in advance for any help.
Just checked a CEL with Icarsoft MB11 reader and it shows a P0675 fault, Cylinder 5 glow plug circuit open.
When I start the car the glow plug light lights up, turns off in a few seconds, then when the engine is running the glow plug light in dash comes back on and stays on for 60 seconds, then turns off.
This happens always when I start up the car for the first time on any given day. After the car is warm and subsequent starts throughout the day, the glow plug light doesn't come on for the extra 60 seconds.
In the meantime does anyone know what the issue could be? Replace glow plug on cylinder 5? Or something else connected to glow plug, a relay perhaps?
Do cylinder numbers go from front of vehicle rearwards? If this is the case then 2nd glow plug nearest cabin is the one in question. Or is it the 2nd one from front of vehicle?
Not very well versed in electrical fixes, but with some guidance from all you experts, I can work it out.
Thanks in advance for any help.
MBWorld Fanatic!
Joined: Jan 2009
Posts: 9,225
Likes: 1,798
From: V E G A S
1922 Ford Model T / no OBD
So you don't trust computer when it is telling you bad #5 GP ?
You can confirm that by disconnecting the plug at the module and check each plug resistance.
When you get ready for replacement - find breaking torque and use it wisely as occasionally those plugs get glued with soot and break.
MB made nice video about recommendation for soaking the plug with motor oil and driving with it for a week.
You can confirm that by disconnecting the plug at the module and check each plug resistance.
When you get ready for replacement - find breaking torque and use it wisely as occasionally those plugs get glued with soot and break.
MB made nice video about recommendation for soaking the plug with motor oil and driving with it for a week.
Junior Member
Joined: Aug 2007
Posts: 36
Likes: 1
From: B. C. Canada
2005 E320 CDI
Failed Glow plug relay
I had much the same symptoms; Switched around the suspect glow plug to another hole and the trouble did not go with the switch. (maintained the trouble was in the same hole)
Conclusion; Bad Glow plug relay;replaced and restored to normal.
I have an 2005 E320 CDI with 220,000 kM
Cost $130 Cdn plus labour.
Also notable was that the relay attaching bracket had come loose and it was hanging by it's harness
David
Conclusion; Bad Glow plug relay;replaced and restored to normal.
I have an 2005 E320 CDI with 220,000 kM
Cost $130 Cdn plus labour.
Also notable was that the relay attaching bracket had come loose and it was hanging by it's harness
David
Last edited by doxland; Aug 17, 2019 at 05:47 AM. Reason: Additional info
Thread Starter
Member
Joined: Aug 2017
Posts: 96
Likes: 13
From: Waterloo, Ontario
2005 E320 CDI,
Thanks, appreciate the input, once it stops raining, I’ll get to it. I have seen the video where you soak the glow plug for a number of days for easier removal. Also good tip about using the 5V plug vs the 12V.
Super Member
Joined: Jan 2010
Posts: 563
Likes: 31
From: The Villages, Florida
2006 E320 CDI
Whenever I had a defective glow plug, I had a steady error light. It did not go out. With my Glow plug relay, I believe that the light may act like you described.
Mike T.
Mike T.
Thread Starter
Member
Joined: Aug 2017
Posts: 96
Likes: 13
From: Waterloo, Ontario
2005 E320 CDI,
Is the glow plug relay the same as the glow plug controller?
Of all the faults I have to get cylinder 5 fault.
How the heck do you get access to this plug? There is hardly any room.
I'd like to get the engine hoist bracket off to get more access, but the fuel rail is in the way.
I'm going to oil the glow plug holes for the next few days anyway.
Any suggestions?
Of all the faults I have to get cylinder 5 fault.
How the heck do you get access to this plug? There is hardly any room.
I'd like to get the engine hoist bracket off to get more access, but the fuel rail is in the way.
I'm going to oil the glow plug holes for the next few days anyway.
Any suggestions?
Super Member
Joined: Jan 2010
Posts: 563
Likes: 31
From: The Villages, Florida
2006 E320 CDI
Yes the relay is the same as the controller. As per the attached document, if you had a bad glow plug, the dash light would not go out after the motor is started.
Mike T.
Mike T.
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MBWorld Fanatic!
Joined: Jan 2016
Posts: 2,758
Likes: 889
From: In the Shadow of the Tetons
2013 ML350 Bluetec
I've had the symptoms the OP describes in the first post and the cause was (2) plugs that weren't totally bad just GOING bad. The resistance was high enough to trip the light but not high enough to be completely dead. Cold starts were normal, just-off-cold starts left a glow plug light on for a minute or two after starting, hot starts had no issue. Changed the questionable plugs and all is well.
OP, make sure you use the proper (Bosch 5V) glow sticks or you're gonna have issues. 12V plugs won't work well at all.
OP, make sure you use the proper (Bosch 5V) glow sticks or you're gonna have issues. 12V plugs won't work well at all.
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Thread Starter
Member
Joined: Aug 2017
Posts: 96
Likes: 13
From: Waterloo, Ontario
2005 E320 CDI,
2005 Inline 6 3.2 L
So, I thought I would give an update.
Ordered 6 5V Beru glow plugs online, got them yesterday and saved around $70 Cdn buying online compared to dealer (Canada).
Only #5 showed the fault, but I thought I would do all 6 right away as I didn't know when they were last changed.
Just installed them today, I used a 1/4 drive with 10mm deep socket, as the 3/8" drive interferes too much especially on number 4 plug. The 3/8 drive does work on all other plugs
My #5 glow plug had the fault, when I checked the resistance it was around 150 ohms.
But I have to say this one was a bugger to get out. I used the 3/8 drive on this one and while I could turn it out with difficulty, I could not pull the plug out once the threads were released.
I even modified an old flathead screwdriver, by bending the tip 90 degrees.I ground out the tip center to create a fork, then got the fork around the plug end. I put on a puller before I bent it 90 degrees so I could use the upward force to hopefully get the plug out. Still couldn't get it out.
I was almost ready to give up, when I remembered a thread I'd read on the forum here that starting the engine might just release the stuck plug.
I covered the plug with a rag stuffed in there and gave the engine a quick start.
As soon as the engine fired up, I heard a big pop and then I knew the plug was out of the hole.
The new plug went in easy, as all the others did.
Lots of carbon on the shank, which is why it was in there so tight.
New one goes in real easy,
Used the MB11 to clear the fault code, and now no more CEL.
This is my first attempt at changing out glow plugs and glad I did.
So, I thought I would give an update.
Ordered 6 5V Beru glow plugs online, got them yesterday and saved around $70 Cdn buying online compared to dealer (Canada).
Only #5 showed the fault, but I thought I would do all 6 right away as I didn't know when they were last changed.
Just installed them today, I used a 1/4 drive with 10mm deep socket, as the 3/8" drive interferes too much especially on number 4 plug. The 3/8 drive does work on all other plugs
My #5 glow plug had the fault, when I checked the resistance it was around 150 ohms.
But I have to say this one was a bugger to get out. I used the 3/8 drive on this one and while I could turn it out with difficulty, I could not pull the plug out once the threads were released.
I even modified an old flathead screwdriver, by bending the tip 90 degrees.I ground out the tip center to create a fork, then got the fork around the plug end. I put on a puller before I bent it 90 degrees so I could use the upward force to hopefully get the plug out. Still couldn't get it out.
I was almost ready to give up, when I remembered a thread I'd read on the forum here that starting the engine might just release the stuck plug.
I covered the plug with a rag stuffed in there and gave the engine a quick start.
As soon as the engine fired up, I heard a big pop and then I knew the plug was out of the hole.
The new plug went in easy, as all the others did.
Lots of carbon on the shank, which is why it was in there so tight.
New one goes in real easy,
Used the MB11 to clear the fault code, and now no more CEL.
This is my first attempt at changing out glow plugs and glad I did.
MBWorld Fanatic!
Joined: Jan 2009
Posts: 9,225
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From: V E G A S
1922 Ford Model T / no OBD
That too, but MB has special grease to fill up long shafts on GP and injectors.
I think it is silicone grease, but finding substitute would take whole research.
I think it is silicone grease, but finding substitute would take whole research.
Junior Member
Joined: May 2013
Posts: 57
Likes: 10
From: Michigan
Two 2005 E320 CDI, 2004 E500 Wagon, 2007 ML63 4MATIC
I have the same issue my 05 CDI. Fault first tripped last weekend. Glow Pluge #5.
FCP euro sells this grease for glow plugs/injectors. Where exactly should the grease be applied? I can't imagine you want this on the tip.
https://www.fcpeuro.com/products/mer...i-000989425110
FCP euro sells this grease for glow plugs/injectors. Where exactly should the grease be applied? I can't imagine you want this on the tip.
https://www.fcpeuro.com/products/mer...i-000989425110
Thread Starter
Member
Joined: Aug 2017
Posts: 96
Likes: 13
From: Waterloo, Ontario
2005 E320 CDI,
Thanks for this, I just opened an account with FCP 2 weeks ago, when I was shopping for glow plugs, but didn’t purchase the plugs from them after all.
Can anyone tell me why fuel economy has improved since I have replaced my faulty glow plug. Just going by readout on the dash, not calculated, but it seems to be a pretty big difference. Don’t understand how this can affect fuel economy to this degree.
Can anyone tell me why fuel economy has improved since I have replaced my faulty glow plug. Just going by readout on the dash, not calculated, but it seems to be a pretty big difference. Don’t understand how this can affect fuel economy to this degree.
MBWorld Fanatic!
Joined: Jan 2009
Posts: 9,225
Likes: 1,798
From: V E G A S
1922 Ford Model T / no OBD
Consider Placebo effect? Are you driving more carefully after the repair? We often do - paying more attention to cluster lights than to traffic.
Than diesels fuels have wide spread in btu.
Old boaters myth is that experienced diesel boater could tell what refinery the fuel come from by listening how engine works.
Than diesels fuels have wide spread in btu.
Old boaters myth is that experienced diesel boater could tell what refinery the fuel come from by listening how engine works.
Thread Starter
Member
Joined: Aug 2017
Posts: 96
Likes: 13
From: Waterloo, Ontario
2005 E320 CDI,
Can’t say that I’m driving any different than before. I’m going to monitor a few tank fulls and calculate kms vs fuel used at fill up and then compare to previous mileage.
