Interesting Glow Plug Article
Senior Member
Joined: Jan 2011
Posts: 422
Likes: 52
From: McDade, Texas
W211 e320 CDI
Just in case anyone is wondering which plugs to buy on Peach...the answer is most definitely the Beru plugs, not the Bosch plugs. I had a couple less than stellar stock plugs so replaced all six, though Bosch would be the way to go. They work, no harm no foul right, been running them for about 20k miles now but in testing there was no darn near instant glow action so I'm guessing I currently lack some of the features modern glow control is capable of. Car runs perfect but next time I'm under the hood I have a set of Beru plugs to replace. My mistake, Pelican listed two possibilities and I figured the more expensive option better.
This advise is only for 05-06 inline six CDI W211.
Some pics in case you have never seen your glow plugs, I'll save you some time and show you mine...lol...that sounded a little bad...
Old and new, with anti seize ready to go, contrary to what you may have heard this is actually an easy job.
Can you guess which ones were sucking and which were working right?
Old vs new and wrong but still functional.
I've had no issues with power supply/control unit and since I have a very healthy motor it's really pretty transparent, I still will make it right next time I have some serious under hood time planned.
This advise is only for 05-06 inline six CDI W211.
Some pics in case you have never seen your glow plugs, I'll save you some time and show you mine...lol...that sounded a little bad...
Old and new, with anti seize ready to go, contrary to what you may have heard this is actually an easy job.
Can you guess which ones were sucking and which were working right?
Old vs new and wrong but still functional.
I've had no issues with power supply/control unit and since I have a very healthy motor it's really pretty transparent, I still will make it right next time I have some serious under hood time planned.
Senior Member
Joined: Mar 2009
Posts: 430
Likes: 6
From: USA, EU
06 E320 CDI (GONE), 14 Jeep GC EcoDiesel, 01 Disco II (GONE), 09 BMW X3 3.0 Si Xdrive
Main problem with Bosch is the voltage - around 12V but glow plugs used on north american CDI is 5V glow plug, thus not enough heat when engine is cold starting. Bosch also make 5V plugs but they are not available in USA. If you put correct voltage plug it will work does'n matter who makes them. It may not have any difference for you because of the climate you live but it will make huge difference for some one living in place with temperature around freezing (he will see lots of smoke and unstable engine work until engine warms up).
Out Of Control!!
Joined: Aug 2010
Posts: 12,516
Likes: 628
From: Charlotte NC area
2019 WS222 S450 4-Matic / 2007 W211 E350 4Matic (Sold) / 2008 X164 GL320 CDI
Main problem with Bosch is the voltage - around 12V but glow plugs used on north american CDI is 5V glow plug, thus not enough heat when engine is cold starting. Bosch also make 5V plugs but they are not available in USA. If you put correct voltage plug it will work does'n matter who makes them. It may not have any difference for you because of the climate you live but it will make huge difference for some one living in place with temperature around freezing (he will see lots of smoke and unstable engine work until engine warms up).
I have seen this discussed, but hard to believe there would be such a significant error in the cross reference tables.
Senior Member
Joined: Jan 2011
Posts: 422
Likes: 52
From: McDade, Texas
W211 e320 CDI
There is however, there is indeed. Coldest weather I've been in this year for a cold start was about 18F, just cycled key/plugs three times and it lit right off like usual. A healthy diesel barely needs glow plugs to run if at all so it's not a huge deal, as compression goes down they are the difference between running and not. I don't idle any of my engines more than is required to get throttle response, less than thirty seconds on the cdi even with these glow plugs in cold weather, I take it real easy on the motor in any of my cars/bikes/plane until up to temp cause I'm OCD like that.
Trending Topics
Senior Member
Joined: Mar 2009
Posts: 430
Likes: 6
From: USA, EU
06 E320 CDI (GONE), 14 Jeep GC EcoDiesel, 01 Disco II (GONE), 09 BMW X3 3.0 Si Xdrive
MB World Stories
The Best of Mercedes & AMG
6 Mercedes Models That Did NOT Age Well (But Are Somehow Still Cool)
Verdad Gallardo
Manual Mercedes? 6 Times Sindelfingen Let Drivers Have All The Fun
Verdad Gallardo
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren
Verdad Gallardo
8 Classic Boxy Mercedes Designs That Have Aged Like Fine Wine
Verdad Gallardo
Flawlessly Restored Mercedes 190E Evo II Heads to Auction
Verdad Gallardo
Electric Mercedes C-Class Unveiled: 11 Things You Need to Know
Verdad Gallardo
Mercedes EQS Gets A Major Update: Everything You Need to Know
Verdad Gallardo
5 Underrated Mercedes-Benz Models That Don't Get the Love They Deserve
Verdad Gallardo
Mercedes 300D Has Pushed Well Past 1 Million Miles and It Ain't Stopping
Verdad Gallardo
Out Of Control!!
Joined: Aug 2010
Posts: 12,516
Likes: 628
From: Charlotte NC area
2019 WS222 S450 4-Matic / 2007 W211 E350 4Matic (Sold) / 2008 X164 GL320 CDI
Senior Member
Joined: Jan 2011
Posts: 422
Likes: 52
From: McDade, Texas
W211 e320 CDI
Yes, that appears to be the case based on my reading and it has been more extensive than this one thread. I forgot to add a set yesterday to a parts order so obviously the 12V plugs are not an issue for me here in tropical Texas.
Senior Member
Joined: Mar 2009
Posts: 430
Likes: 6
From: USA, EU
06 E320 CDI (GONE), 14 Jeep GC EcoDiesel, 01 Disco II (GONE), 09 BMW X3 3.0 Si Xdrive
Senior Member
Joined: Mar 2009
Posts: 430
Likes: 6
From: USA, EU
06 E320 CDI (GONE), 14 Jeep GC EcoDiesel, 01 Disco II (GONE), 09 BMW X3 3.0 Si Xdrive
Out Of Control!!
Joined: Aug 2010
Posts: 12,516
Likes: 628
From: Charlotte NC area
2019 WS222 S450 4-Matic / 2007 W211 E350 4Matic (Sold) / 2008 X164 GL320 CDI
Senior Member
Joined: Jan 2011
Posts: 422
Likes: 52
From: McDade, Texas
W211 e320 CDI
5V heats MUCH faster, more capable of trimmed warm up operation. The PDF article in the OP is actually fascinating and seems very pertinent to Beru glow plugs of this type specifically. Not a terribly long or mundane read either.
Out Of Control!!
Joined: Aug 2010
Posts: 12,516
Likes: 628
From: Charlotte NC area
2019 WS222 S450 4-Matic / 2007 W211 E350 4Matic (Sold) / 2008 X164 GL320 CDI
I can see the advantages, I just wonder the tradeoffs, that keep two types required?
Senior Member
Joined: Jan 2011
Posts: 422
Likes: 52
From: McDade, Texas
W211 e320 CDI
Having owned at least 4 other turbo diesels and one plain naturally aspirated diesel, plug life is the biggest issue I've personally seen, and my W211 is working near perfect on the 12V plugs. I will swap back to the 5V higher amperage units soon enough just to be certain but I'm guessing cold start/running emissions are the driver, more frequent changes are end users problem. Since I'm the end user, my problem.
Senior Member
Joined: Mar 2009
Posts: 430
Likes: 6
From: USA, EU
06 E320 CDI (GONE), 14 Jeep GC EcoDiesel, 01 Disco II (GONE), 09 BMW X3 3.0 Si Xdrive
Second set for last 5 years (I prefer to change them in set when one fail). In general after second year one will fail. I am not sure that this is not result of GPC module problem or ECU software version but I am going to find out since I upgraded ECU software last year.
Thread Starter
Super Member
Joined: Jan 2010
Posts: 563
Likes: 31
From: The Villages, Florida
2006 E320 CDI
Out Of Control!!
Joined: Aug 2010
Posts: 12,516
Likes: 628
From: Charlotte NC area
2019 WS222 S450 4-Matic / 2007 W211 E350 4Matic (Sold) / 2008 X164 GL320 CDI
I have a Keyless Go, so have no control over the start cycle.
(We I could play games by hitting the button with my foot off the brake, but not really sure if that activates the glow plugs or not)
GL has 113K but lived its first 96K in warm weather. So far no plug replacements (Did replace the controller module)
(We I could play games by hitting the button with my foot off the brake, but not really sure if that activates the glow plugs or not)
GL has 113K but lived its first 96K in warm weather. So far no plug replacements (Did replace the controller module)
Senior Member
Joined: Mar 2009
Posts: 430
Likes: 6
From: USA, EU
06 E320 CDI (GONE), 14 Jeep GC EcoDiesel, 01 Disco II (GONE), 09 BMW X3 3.0 Si Xdrive
Back then when MB brought 320 CDI to the states diesel fuel had high sulfur content, now all this is not necessary since levels are very low. You may have 11 V glow plugs in your GL since is newer.
Senior Member
Joined: Jan 2011
Posts: 422
Likes: 52
From: McDade, Texas
W211 e320 CDI
I don't know much about the V motors other than we have a dead stock Sprinter with one here at the shop but, on the inline six motor replacing them was a very simple job, no harder than spark plugs in most inline six gas motors. I definitely agree that it borders on a non issue, I've noticed no difference at all in how my car runs other than on the very coldest start I've had in four years, it took two attempts...that's been my worst case scenario even with the 11-12V plugs in place.
