Stirring the pot -

Does anyone have stats on the average lifecycle of glowplugs in miles? I know start cycles and glow time are a better measure of life expectancy but it occurs to me that our Mopar minivan will get its third set of spark plugs at 200K miles, now at 193K miles. Based on the frequency of glow plug replacement topics and whining about 603 and 606 difficulties, it seems our cars can't stretch 100K miles from a set of glow plugs. Mind you, it's easier to replace 603 glow plugs (never done a 606) than the rear bank plugs of that darn Mopar 3.3.

Sixto
87 300D

I've had real good luck with the French Made Bosch Duraterm plugs....my current set are going on 3 years (with many many starts) and I have the afterglow system on top of it. If they average 25,000 miles I'm happy.

Don't get me started on the rear plugs on a caravan 3.0! I have permanent scars!!

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-diesel is not just a fuel, its a way of life-
'15 GLK250 Bluetec 118k - mine - (OC-123,800)
'17 Metris(VITO!) - 37k - wifes (OC-41k)
'09 Sprinter 3500 Winnebago View - 62k (OC - 67k)
'13 ML350 Bluetec - 95k - dad's (OC-98k)
'01 SL500 - 103k(km) - dad's (OC-110,000km)
'16 E400 4matic Sedan - 148k - Brothers (OC-155k)

The 603 Engine uses Glow Plugs that are the same physical size as the 617s and the shorter GPs just rarely get stuck and I have not read of one snapping off like the longer 606 GPs.
It is clear that the long GP + an Aluminum Cylinder Head is not a good combination without some Never-Seeze type compound on the threads of the GP; and even that does not stop the GP tips from getten trapped by Carbon.

I think you would have to spend the extra money to buy Beru Glow Plugs and at the same time make sure your Injectors and the IP timing were all performing well so as to reduce Carbon build up around the plug tip in order to get a long life out of the Glow Plugs.

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84 300D, 82 Volvo 244Gl Diesel

My 606 at 265K is on its 1st replacement set of GP's; that set currently has 155K on them. Never used never sieze; never had one stuck.

OEM for the 606 were Beru GP's.

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Terry Allison
N. Calif. & Boca Chica, Panama

09' E320 Bluetec 77k (USA)
09' Hyundai Santa Fe Diesel 48k (S.A.)

TMAllison - you're a very lucky 606 owner!

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95 E300 Diesel 265k and counting

I am at 106,000 on the set I installed back in DEC 05. The previous owner had replaced them after about 60,000. I did put Never Sieze on them when I replaced them and will keep my fingers crossed when I need to change them again. Most of my driving is highway, and get the chance to really blow it out, so hopefully the soot buildup wont be an issue.

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Dennis
2006 E320 CDI Black/Black Leather. Nav, HTD Seats HK stereo 32000 miles.
2000 VW Passat 1.8t 300,000 miles as of Dec 09, 2009 original owner
1997 E300d Silver 300,000 miles As of Jan 05, 2010
3rd owner SOLD

The last set of Beru plugs I bought were about $7 a piece.

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Michael LaFleur

'05 E320 CDI - 86,000 miles
'86 300SDL - 360,000 miles
'85 300SD - 150,000 miles (sold)
'89 190D - 120,000 miles (sold)
'85 300SD - 317,000 miles (sold)
'98 ML320 - 270,000 miles (sold)
'75 300D - 170,000 miles (sold)
'83 Harley Davidson FLTC (Broken again) :-(
'61 Plymouth Valiant - 60k mikes
2004 Papillon (Oliver)
2005 Tzitzu (Griffon)
2009 Welsh Corgi (Buba)

From memory, Beru's for the 606 are about $32 ea on this site; bosch about $25ish.

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Terry Allison
N. Calif. & Boca Chica, Panama

09' E320 Bluetec 77k (USA)
09' Hyundai Santa Fe Diesel 48k (S.A.)

Retail?
Pulled at the Junk Yard?
Women selling her Ex's stuff to get revenge?

I suppose it is possible to get lucky on Ebay or find some from a person who no longer has their Car and get a bargin price on them.

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84 300D, 82 Volvo 244Gl Diesel

Granted they were the series-wired loop style of GP's, but we drove the '68 220D for about 20 years and a couple hundred thousand miles and never changed the glow plugs. Near the end of driving that car I bought a set of four new ones to put in, thinking that it had maybe gone far enough on the first set!?! Never did put them in and eventually sold them.

So much of that car could permanently spoil you when it came to minimal need for maintenance.

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1961 190Db retired
1968 220D/8 325,000
1983 300D 164,150

Members claim that Carbon build up around the tip of the Pencil tye Glow Plugs causes them to fail early.
No one seems to know exactly why.
The reason I have read that seemed most logical is that the Carbon conducts part of the heat from the Glow Plugs into the Cylinder Head instead of heating the Air or Fuel spray from the Nozzle.
I nticed when I hooked up a single Glow Plug to an automotive Amp Meter and connected it to a Battery I noticed it pegged the Meter at 60 amps for a second or 2 and as it got hot the amps went down to aroubnd 16.
So when the GP was cold it pulled high amps=high resistance, hot GP= Low amps and Low resistance.
A Glow Plug that is conducting the heat into the Cylinder Head due to Carbon Build up would remain cooler and pull higher amps longer and maintain a higher resistance for a longer period. My guess is this is what kills them early.

With the loop style Glow Plugs the element protrudes and hangs out into the Pre-chamber no where near where it could conduce heat into the Cylinder head. So this could explain the longer life.
The only thing that comes to mind that would kill the Loop Style GPs operating normal is if the Injector Spray Nozzle spray pattern was off and sprayed too much onto the Glow Plug Element; over a period of time this would burn it into.

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84 300D, 82 Volvo 244Gl Diesel

I am a newbie. Anything I say about diesels is second hand. I am gathering information now to make an informed purchase decision, and maintain the engine to enjoy the legendary (or mythical) 1,000,000 miles.

I was told that the rod bending in OM603 SD motors is not mysterious at all. The most likely cause is a glow plug that fails causing the diesel to come out like a garden hose instead of mist; Condition is called hydrolock?

That same person said that glow plugs generally last 120k, but changing at 60k was cheap insurance against a rod bending incident.

I would accept that information as accurate and true. Compared to the cost of bent rod, a set of glow plugs every 60k is cheap. My old mechanical mentor told me "oil is cheap, motors are expensive" in regard to frequent oil changes.

Has anyone else heard this advice on replacing glow plugs at 60k, "whether it needs it or not"?

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1962 220Sb ~ The Emerald Bullet http://www.youtube.com/watch?v=hx6tN1W48_o
1957 Ponton 220S
2001 S600 Daily Driver
The Universe is Abundant ~ Life is GOOD!http://www.classiccarclock.com

That is just another random guess many people have made to try and rationalize the rod bending problem. Nobody knows the actual reason(s) except the engineers at Mercedes and they aren't even directly acknowledging there is a problem in the first place.

Based on his record of guessing about the rod bending problem and lack of knowledge about the glowplug's role in the engine, I believe the person doesn't know much about diesels at all.

Glow plug life varies drastically by driving style. A person that drives hundreds of miles on the highway at a time may never need glowplugs, but a person that does frequent short trips may need one or more every year.

Changing them on time/mileage is a waste of money. When you buy the car, remove them, ream the carbon out of the holes, coat the GP threads with electrically conducting high temperature anti-seize and forget them until one burns out.

What you say about highway mileage affecting glow plugs differently than short local trips makes sense.

Admittedly, I don't know anything about diesels. If the glow plug burns out, what happens? Can unburned fuel in the cylinder cause a rod to bend if it is somewhat inclined to do so?

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1962 220Sb ~ The Emerald Bullet http://www.youtube.com/watch?v=hx6tN1W48_o
1957 Ponton 220S
2001 S600 Daily Driver
The Universe is Abundant ~ Life is GOOD!http://www.classiccarclock.com

The engine will run rough on that cylinder until heat from compression is warm enough to ignite the injected fuel. 30 seconds to 2 minutes depending on ambient temperature.

Not even remotely possible.
The injected quantity at idle is in the order of parts of a droplet of fuel. Even at full power (when the most fuel is injected), the volume is in cubic millimeters (about 85mm3). Each cylinder is 583,000mm3, so at maximum fuel flow it can only inject enough fuel to occupy 1/6859th the volume of air moved though the engine. Some fuel will condense when it contacts the cylinder walls but most will be blown out of the engine during the exhaust stroke.