Mercedes-Benz Forum banner

1 - 20 of 39 Posts

·
Registered
2011 E350 Bluetec
Joined
·
4 Posts
Discussion Starter #1
Hello all,

I have a W211 2005 E320 CDI, US model with approximately 67,000 miles on it. About two months ago I had to replace a faulty glow plug. Last night, the glow plug light remained on, and the CEL illuminated as well, so I'm assuming I have to replace another plug.

My question - is replacing glow plugs at 60K miles normal and expected? Or, is there possibly something else going on like a faulty temperature sensor, or faulty glow plug relay?

Thanks in advance!

Tom
 

·
Registered
2006 E320 CDI, 2009 ML320 Bluetec, 2009 GL320 Bluetec
Joined
·
1,476 Posts
Take the car in and have the dealer scan it with STAR to determine what codes are stored.

Glow plugs can last hundreds of thousands of miles without failing, they are a simple device that either works or it doesn't. There is no specified life to them since all they do is heat up when current passes thru them (simplified version.

DB
 

·
Registered
2008 E320 Bluetec; 2012 C250 Sedan; 2012 ML350; 2013 S350 Bluetec; 2013 GLK 350
Joined
·
171 Posts
I too have a '05 W211 US Spec CDI (with 78K miles on it). Two weeks ago I noticed the glow plug light staying on for a minute or so after the engine started but it only happened a couple of times. The day before yesterday, the CEL came on so I dropped it at the dealer for diagnosis. Result: $600 for all new glow plugs. Dealer says despite being a CPO vehicle (and still within the CPO warranty) glow plugs are considered a "wear and tear" item and therefore not under any warranty. :>(

What a surprise! Even my '83 Olds Diesel had glow plugs last more than 100k miles. Very disappointed in that but very happy with the rest of the car. :>)
 

·
Registered
2006 E320 CDI, 2009 ML320 Bluetec, 2009 GL320 Bluetec
Joined
·
1,476 Posts
$600? Wow...You can swap them out in under 20 minutes with a 10mm deep 1/4" drive socket.

Price per plug is around $30.00 (Latests and greates ceramic).

By the way you don't replace them as a set, you only do that with spark plugs. With glow plugs you only replace the bad one and press on.

You can check them very easily by ohm'ing them typically .9-1.3 is the optimal range.
 

·
Registered
222.132 & 221.122 & 213.050 & 906.633
Joined
·
10,425 Posts
I guess it depends on the weather the car is driven. At colder climates the glow plugs work always a bit, they are just fast and one may not notice it (plus the post-glow time).

I've seen glow plug issues at less than "hundreds of miles", 67 000 sounds low though.

Also the plugs on a CDI are really long and thin. If they have got stuck, one would better leave the work for an expert. The plugs may snap and then it is really difficult to get the rest out (with special tools). If the plug turns smoothly, then there is nothing to worry about a DIY task. One should figure out how to handle the thread to make it come out next time.
 

·
Registered
2006 Merc E320 cdi
Joined
·
981 Posts
I had one plug go out at about 62000 miles. Took it to the dealer and all 6 were replaced under CPO warranty.
Not sure of the durability of Merc plugs, but this seems kinda low. I'm planning to make this a DIY project if it happens out of warranty, tho..
 

·
Registered
2008 E320 Bluetec; 2012 C250 Sedan; 2012 ML350; 2013 S350 Bluetec; 2013 GLK 350
Joined
·
171 Posts
$600? Wow...You can swap them out in under 20 minutes with a 10mm deep 1/4" drive socket.

Price per plug is around $30.00 (Latests and greates ceramic).

By the way you don't replace them as a set, you only do that with spark plugs. With glow plugs you only replace the bad one and press on.

You can check them very easily by ohm'ing them typically .9-1.3 is the optimal range.
DBW, Thanks for the info! Next time I'll try it myself and hope the dealer tech didn't put threadlock on 'em. :)
 

·
Registered
95SS(165k) 06CDI(SOLD) 2014 GLK250
Joined
·
396 Posts
WOW all this talk and this morning I get the glowplug light......

i think i may have done it though.... I dont think i waited for the GP light to go out before trying to crank it and now it gave me a check engine......

did i do a dumb thing and give myself a check engine?? or was it bound to happen?
 

·
Registered
2006 Merc E320 cdi
Joined
·
981 Posts
WOW all this talk and this morning I get the glowplug light......

i think i may have done it though.... I dont think i waited for the GP light to go out before trying to crank it and now it gave me a check engine......

did i do a dumb thing and give myself a check engine?? or was it bound to happen?
Don't know. My car has keyless-go. This is a concern for me since the keyless-go unit may say start when I should be waiting for the glows.. It even starts right up in really cold weather (20's).

Depending upon the mileage of your car this was probably bound to happen. I've heard some stories about getting the glow plugs out about the torque and you have to be careful not to break the plug trying to remove it.

OTOH, the check engine might be for something other than the glow plugs..
Good luck.
 

·
Registered
E320/E250 Bluetec Ford F350 6.7l
Joined
·
36,471 Posts
I never waited for GP while starting my cdi.
Actually took me couple of weeks to notice the light. Used to the light in the right corner on older models took me several tries to notice smaller light coming in the center for just seconds.
GP don't trigger CEL. Get the car scanned.
 

·
Registered
2006 E320 CDI
Joined
·
239 Posts
To further what Kajtek1 said, there is no requirement that you wait for the glow plugs. Valets certainly have no clue about them and just start the car up. Doesn't hurt. If they had to burn through their cycle before the car was started, MB would have inserted a lockout in the system to prevent starts before the glows were done doing their thing.
 

·
Registered
2006 E320 CDI
Joined
·
239 Posts
It even starts right up in really cold weather (20's).
I'd hope so! 20's isn't especially cold. At -5F it still starts fine. (I know you are in NC, just messing with you.)
 

·
Registered
95SS(165k) 06CDI(SOLD) 2014 GLK250
Joined
·
396 Posts
well my service advisor @ MB cleared it and let me go i think i did something to make it glitch when i was starting this morning

if it comes back on we know whats wrong and i will bring it back

thanks guys

oh and BTW car has only 33k miles on her....
 

·
Registered
Joined
·
1 Posts
I have an 05 E320 CDI with 18,500 miles. At around 13K I had the GP light stay on. The dealer replaced a bad GB. About 200 miles ago, the same thing happened. (both times the CEL also came on). This time the deal replaced all 6 glow plugs. I have keyless go so the computer is in control of the GP duration.
 

·
Registered
2006 E320 CDI
Joined
·
386 Posts
c

I am now on my third MB diesel that uses these new glow plugs (OM606 and My most recent OM648). All, I repeat All have needed new plugs around 70-75 thousand miles. I just finished the one on my 06 E320 CDI. I was simple but some words of caution -- be careful when removing them -- they break easily if you use too much torque -- The WIS procedure recommends if torque exceeds 24nm to warm up the engine before removal. Mine came out easily on the E320 CDI but that wasn't the case on my 99 E300TD. They were seized and I ended up breaking one -- it is a real pain beyond the point when you break one and a very expensive experience. There are machine shops that can remove them as well as the dealer with special tools.

On my E320 CDI I used a set of long brushes that I got at Harbor Freight for 3-4 dollars to clean the holes. These were just the right size to fit the hole and did a great job. I used some carb cleaner from Walmart to clean all the carbon out of the hole down to the combustion chamber. I also used anti seize on the treads of the new plugs to ensure they will come out easily the next time they go bad. The WIS procedure specifies tightening the plugs to 19nm torque which I did. I used Bosch Duraterm plugs which were $13.60 a piece online. You can get MB Behr plugs for about 24 dollars online from Mercedes Dealers. My local dealers in Wash, DC area wanted from $44 to $80 dollars a piece.

These plugs are different than the older OM617 engine's plugs. These plugs in the newer engines are not only pre glowing but they remain on depending on the temp to aid in combustion until the engine has warmed to some degree to reduce emissions. So I think that that is most of the reason for the shortened life compared to the older plugs.

I would certainly recommend replacing all the plugs at the same time because once one goes the rest are not far behind. If you have to take yours to a dealer or Indy, doing the job one plug at a time is going to get rather expensive. My OBDII code reader identified that cylinder number 5 was bad. I checked all of them after removal with an Ohm meter and of course the bad one read 0 ohms. The others read .4 on the meter set on the 200ohm scale. The new ones read .6 on the same scale.
 

·
Registered
2005 E320 CDI, 1992 300TE, 1999 Porsche 911 Cabriolet
Joined
·
368 Posts
I looked up in WIS about the replacement and edwinwalke is correct. There was one report on replacing glow plugs but three reports on the repair of a busted one in the hole.

My 2005 CDI had only 18,000 miles when my first glow plug went out. But it was four years old at the time so maybe it is an age thing. Anyway, I ordered 6 at $33 but my wife convinced me to only put in #2 (per the OBDII reader). Her logic was this, since they are as easy to replace as a spark plug and they do wear out, why not just save the other five until they are needed. If only one goes bad, it rarely effects starting anyway.

What the hey, I got five new ones sitting in a bag in my garage.

Good luck,
Peter
 

·
Registered
Joined
·
219 Posts
Excellent thead

This is an excellent thread for MB diesel owners. Thanks, guys!

I looked up in WIS about the replacement and edwinwalke is correct. There was one report on replacing glow plugs but three reports on the repair of a busted one in the hole.

My 2005 CDI had only 18,000 miles when my first glow plug went out. But it was four years old at the time so maybe it is an age thing. Anyway, I ordered 6 at $33 but my wife convinced me to only put in #2 (per the OBDII reader). Her logic was this, since they are as easy to replace as a spark plug and they do wear out, why not just save the other five until they are needed. If only one goes bad, it rarely effects starting anyway.

What the hey, I got five new ones sitting in a bag in my garage.

Good luck,
Peter
 

·
Registered
2006 E320 CDI
Joined
·
386 Posts
GF15.20 - P -4020IC Component description for glow plugs 7.12.04
ENGINE 648.961
Location
R9 Glow plugs
The glow plugs are inserted under the
rail in the inlet duct of the cylinder head.
Task
The glow plugs warms the air fed to the
engine in order to prewarm the
combustion chamber in a cold engine.

P15.20-2100 - 06
Design
The glow plug consists of a metal housing with a screw-in thread and an interference -fit glow rod.
The heating element is integrated in the glow rod. It consists of a heating coil and a control coil which are switched in series.
Function (for model 211 )
The glow plugs have voltage applied to them in parallel of 6 to 11 V from the glow output stage (N14/3) and pulsed at the ground
end for preheating.The battery voltage is applied for a short time for a cold start. This makes it possible to reduce the glow time to a
maximum of 3 seconds and to achieve a glow rod temperature of a maximum of 1000°C.
5 V glow plugs are used! THIS IS THE RED FLAG
Page 1 of 1 GF15.20 -P -4020IC
© 2007 Mercedes -Benz USA, LLC

Had an interesting and somewhat expensive find this past weekend and I confirmed my suspicions today after reading the above excerpt from the Star Service Manual library. The Glow plugs that are in our OM648.961 CDI engines are 5 volt glow plugs. The ones I just installed two weeks ago were Bosch and supposedly for my car -- 06 E320 CDI but they are 11.5 volt plugs. I noticed while on a trip after my car set out in the cold all night (high 20s) that when it started it ran rough for a few minutes. What I suspect is the voltage being sent to these plugs was not enough to get them hot enough and I suspect that from the way the car ran the after glow was less than optimal. I just ordered 6 more Mercedes Benz OEM plugs from an online dealer in Shawnee Mission, KS. Their plugs are 23.10 each which is not bad considering the MSRP is 30-32 dollars and some of the local dealers in the Wash, DC area what up to $80 each for the same thing. These guys are on the internet as Mercedes Parts Center and they are a MB dealer. I will also be having a conversation with the online store I bought the Bosch plugs from as they were suppose to be for my car.

Just wanted to share this info so someone else that wants the change their plugs don't get the wrong ones. I would stick with the OEM part -- Part number is 001 159 5101.

So Saturday morning will be another glow plug change. I'll be able to do this blind folded next time around with all this practice.
 

·
Registered
2006 E320 CDI, 2009 ML320 Bluetec, 2009 GL320 Bluetec
Joined
·
1,476 Posts
Well I just had a glow plug go out on me (#2). Ordered a new one but I had to leave early to go on a trip so I had the car dropped off at the dealer for the repair. Anyway, dealer called this afternoon to say the car was done and that they performed an update that replaced all 6 plugs (I suspect an update to the ECU in respect to the control circuit was also performed).

They also replaced the sensor seal on the transmission due to a slight leak (known issue on these).

Anyway, I'll check the paperwork when I get back next week and see what was installed plug wise.
 
1 - 20 of 39 Posts
Top