Hi, , I have a new code: glow plug cyl 6. Is changing the glow plug as straightforward as it appears to be?
Car has 150000 happy miles: performs well, uses no oil in 12000 miles. A keeper.

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Providing a home for these cars:
1951 Buick Special De Luxe
1977 Rolls-Royce Silver Wraith II
1970 Rolls-Royce Silver Shadow
1986 Mercedes-Benz 420 SEL
2005 Mercedes-Benz E 320 CDI
2012 GMC Sierra 1500 4X4
1927 Pierce-Arrow Series 80
1931 Pierce-Arrow Series 43
1926 Ford Model T coupe

Have you checked the resistance of the glow plugs with an Ohm Meter (on your Multimeter) yet?

I am not sure on your particular year but on the Engines that have Aluminum Cylinder Heads and long Glow Plugs it is common to have the hex end of the Glow Plug Break off. Most often due to corrosion between the steel threads and the aluminum treads of the Glow Plug but some have also had carbon leak into that area had the carbon stick the Glow Plugs in place.

There should be some threads on the 606 engines that have some ways to decrease the chances of them breaking. The 2 that I remember are take a couple of weeks sraying the Glow Plug with something like Kroil or PB Blaster and remove the Glow Plugs after a drive when the Engine is nice and hot.

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84 300D, 82 Volvo 244Gl Diesel

Have you checked the resistance of the glow plugs with an Ohm Meter (on your Multimeter) yet?

I have not noticed any Threads where someone removed the Glow Plugs on an Engine as new as yours.

I am not sure on your particular year but on the Engines that have Aluminum Cylinder Heads and long Glow Plugs it is common to have the hex end of the Glow Plug Break off. Most often due to corrosion between the steel threads and the aluminum treads of the Glow Plug but some have also had carbon leak into that area had the carbon stick the Glow Plugs in place.

When the Glow Plugs go back in coat the body and threads but not the element with Beru Glow Plug Grease or some other never-Seize type compound.

There should be some threads on the 606 engines that have some ways to decrease the chances of them breaking. The 2 that I remember are take a couple of weeks sraying the Glow Plug with something like Kroil or PB Blaster and remove the Glow Plugs after a drive when the Engine is nice and hot.

If I was going to remove the long Glow Plugs out of an Aluminun Head I would be sure I had another ride to work incase one or more broke off so I would have time to attempt removal.

Mechanics prefer to pull the cylinder head off and let a machine shop do the removal. That way they get more money for removing and re-installing the head and suffer none of the risk that they would have tring to remove the Glow Plugs with the Cylinder Head still on the Engine.

Do your Glow Plugs have 10mm or 12mm hex heads on them.

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84 300D, 82 Volvo 244Gl Diesel

I am looking at a parts site and they show a Glow Plug Controller "Glow Plug Controller; Glow Time Output Stage; For E320 CDI models only. Unit is located below the intake manifold" and a "Glow Plug Relay/Controller; Pre-Glow Time Relay;
This unit is the Pre-Glow Time Relay located in fenderwell area, this is NOT the glow plug controller."

So if the Glow Plugs themselves Ohm out OK check to see if all Glow Plugs are getting the proper voltage as there is 2 other components that can cause issues.

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84 300D, 82 Volvo 244Gl Diesel

Apparently it's as straightforward as it appears. The PO was showing me around when I bought the car...demonstrating how accessible everything is. He changed his "just for the heck of it" at 113k miles.

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14 E250 Bluetec 4Matic "Sinclair", Palladium Silver on Black, 157k miles
06 E320 CDI "Rutherford", Black on Tan, 175k mi, Stage 1 tune, tuned TCU
91 300D "Otis", Smoke Silver on Tan, 144k mi, wastegate conversion, ALDA delete

19 Honda CR-V EX 70k mi
Fourteen other MB's owned and sold
1961 Very Tolerant Wife

Diesel911, this is an OM648....not the same as OM606 in terms of glow plug difficulty.

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14 E250 Bluetec 4Matic "Sinclair", Palladium Silver on Black, 157k miles
06 E320 CDI "Rutherford", Black on Tan, 175k mi, Stage 1 tune, tuned TCU
91 300D "Otis", Smoke Silver on Tan, 144k mi, wastegate conversion, ALDA delete

19 Honda CR-V EX 70k mi
Fourteen other MB's owned and sold
1961 Very Tolerant Wife

This forum has more information on your E320 CDI. Do a search on changing glow plugs. W211 E-Class - Mercedes-Benz Forum

John

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Certified Registered Nurse Anesthetist (CRNA)
2002 F250 powerstroke with Plantdrive WVO conversion
1983 300SD 190K miles ,sold
2006 E320 CDI

Thanks everyone. I will check the resistance, etc. but I want to be prepared.
Assuming it needs to be changed: soak for 2 weeks, attempt removal with engine hot. Is this correct?

__________________
Providing a home for these cars:
1951 Buick Special De Luxe
1977 Rolls-Royce Silver Wraith II
1970 Rolls-Royce Silver Shadow
1986 Mercedes-Benz 420 SEL
2005 Mercedes-Benz E 320 CDI
2012 GMC Sierra 1500 4X4
1927 Pierce-Arrow Series 80
1931 Pierce-Arrow Series 43
1926 Ford Model T coupe

Mercedes procedure is listed here (page also refers to early service campaign):

I had 2 new glow plugs installed in my 05 E320 CDI 2 mos.

The mechanic I work with recommended to do work with engine warm instead of running temperature hot as this can possibly lead to thread damage.....head is aluminum.

Definitely use a torque wrench.

X2 on pb blaster or some other penetrating oil.

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-- Chris

'95 E300, 216k miles, Silver Surfer
'05 E320 CDI, 138k miles
'07 S550 4matic, 69k miles

Gone but not forgotten:

'76 300D, 350k miles?, SOLD in 1995
'75 240D, 300k miles, SOLD in 1991

Can any generic OBD2 reader delete the codes?

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14 E250 Bluetec 4Matic "Sinclair", Palladium Silver on Black, 157k miles
06 E320 CDI "Rutherford", Black on Tan, 175k mi, Stage 1 tune, tuned TCU
91 300D "Otis", Smoke Silver on Tan, 144k mi, wastegate conversion, ALDA delete

19 Honda CR-V EX 70k mi
Fourteen other MB's owned and sold
1961 Very Tolerant Wife

Apparently stuff happens even to E320 CDIs.
Stuck Glow Plug Removal - Mercedes-Benz Forum

Google search =Mercedes OM648 with broken glow plugs

http://www.dailymotion.com/video/x27y6wq_mercedes-cdi-e320-diesel-seized-or-stripped-glow-plug-problem_auto
"Cylinder 5 scared me....."
http://mbworld.org/forums/diesel-forum/466006-om648-glow-plugs.html

http://mbworld.org/forums/diesel-forum/466006-om648-glow-plugs.html

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84 300D, 82 Volvo 244Gl Diesel

That is why MB specs. torque to loosen plugs at. To minimize trouble, don't exceed the torque values, use pentrating oil, and work with warm engine.

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-- Chris

'95 E300, 216k miles, Silver Surfer
'05 E320 CDI, 138k miles
'07 S550 4matic, 69k miles

Gone but not forgotten:

'76 300D, 350k miles?, SOLD in 1995
'75 240D, 300k miles, SOLD in 1991

The 648 motor is much better than 606 for changing glow plugs. I've broken off a glow plug on my previous 606, then successfully changed others on the 606, as well as successfully changed GPs on my 648.

The key to success is three things...lots of PB Blaster, warm engine, torque wrench. You don't need to soak it weeks ahead, hours is OK. Engine doesn't need to be hot...warm is OK. Torque wrench is important...don't exceed about 40 Nm of off-torque. If it doesn't break free at 40, stop, spray more PB blaster, wait. repeat. It just takes the discipline to be patient.

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Mark in MA
05 MB E320CDI 402k Granite Grey Metallic
05 MB E320CDI 267k Black
05 MB E320CDI 232k White
05 MB E320CDI 209k Tectite Grey
99 Dodge 2500 Cummins 5sp 148k
62 Jeep CJ-6 120k

Yes, there is a group of methods that reduce the chance of breakage but there is no group of methods that guarantees 100% success.
However, the fact that the Prior Owner changed them in the past is likely to increase the odds of easy removal.

There has even been 2 instances I have read of where people have broke of the Glow Plugs in an OM617.952 and about as many have gotten the Glow Plug body our only to find the Tip/Heater Element was still stuck in the head.
The frequency of Glow Plug breakage during removal of the longer Glow Plugs in Aluminum Cylinder heads on Mercedes is rather common.

I think you have a choice to be pessimistic (I am nearly always pessimistic about things) and plan for the worst by having another ride available or being optimistic and suffering that extreme disappointment and having to scramble to get a ride to work or school during the time it takes to resolve the issue.

Anyway best wishes.

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84 300D, 82 Volvo 244Gl Diesel

What if all the above is done and you did not break the Glow Plug off but still cannot get it out?

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84 300D, 82 Volvo 244Gl Diesel