Good Morning All,
Got in this morning. (Beautiful Florida morning). Gave my moment of silence to Mr. Rudolph Diesel. The glow indicator came on. Went off. Started normally. Placed vehicle in Reverse. Then the glow indicator came back on. NUTS I thought. Came back home. Shut down. Attempted a restart. No Glow light came on. Then it started.. Glow light on. NUTS....

HANS we have a problem...

OK... Fault in Glow Plug System...

1. Interrupt in the cable to connection Terminal 30.. (Yeah right)
2. Preglow time relay faulty (Maybe)
3. Interrupt in one or several cables to the glow plugs. (nice way of saying check connections)
4. Interrupt in one or several glow plugs. (nice way of saying replace plugs)
5. Short-circuit at one or several glow plugs or in the cables.

Looks like its time to ohm out the glow plugs.

OK.. Ohm check on the Glow Plugs
#1 = 1.1
#2 = OPEN
#3 = 1.1
#4 = 1.1
#5 = 1.1

Hmmm... We have a winner. Checked from the wire connector plug and at the glow plug connector. Couldn't access 3, 4 at the glow plug wire terminal (bolt/nut) connector (intake plumbing in way).

Couple questions:

1. Bosch or Meyle plugs? Does it matter? (Bosch $16.99/Meyle $14.78)
2. Replace all?
3. Remove crossover pipe?
4. Any other suggestions?

Attached Thumbnails

   

__________________
92 300D 2.5L OM602 OBK #59

If the above means you could not access 3 and 4 at the Glow Plug Connector that plugs into the GP Relay; I believe this would indicate a wiring problem; an open circuit. Is this one of the Model Years that has the Bio-degradable wire insulation?

I have not read anything at all concerning Meyle GPs.
Since you live in Florida and do not have to worry about making it through a Winter I would think you could just replace the no good GPs. I do not know about your Engine but if the GPs are hard to get at then I might think of changing all at one time and saving the ols good ones for spares.

Also when you install the new ones ream or otherwise clean the carbon out of the GP holes and use a Never-Seez type compound of if you can find it that Beru Glow Plug Grease on the threads of the new GPs so as to reduce the chance that they will get stuck the next time they have to come out.

__________________
84 300D, 82 Volvo 244Gl Diesel

OOPS.. To clarify.. Plugs 3 and 4 couldn't be checked at the screw terminal. Intake in way. But checked good at the plug connector. All 1.1 Ohm except #2. (Its an easy one to get to) Somewhat.

I'm leaning towards doing just the one glow plug (#2) with Bosch GP. (I'll use some anti-sieze. Also the Glow Plug relay has been replaced in the past.

I've read that good ohm reading are .5 -2 ohms.

__________________
92 300D 2.5L OM602 OBK #59

While your in there looking at things, have you inspected the strip fuse? They tend to get fatigue cracks and act weird just before they fail. Its on the GP Relay.
As for readings, since few Ohmmeters are very accurate at low resistances, just check that the plugs all read near the same resistance, around 1 Ohm or less. If any are "off" compared to the rest, I'd change them. In fact I usually change ALL of then when one goes bad, its the fact of life that when one has failed another is soon to go likewise. And PLEASE do yourself a favor and DO NOT use off brand (including Champion) brand GP's - Beru or Bosch are good.

__________________
'95 E320 Wagon my favorite road car. '99 E300D wolf in sheeps body, '87 300D Sportline suspension, '79 300TD w/ 617.952 engine at 367,750 and counting!

Just replace the bad one.#2 is easy! No sense making a big job out of it,if it were one of the difficult ones and you had to remove the manifold(not really necessary) then i would probably do them all. Don

__________________
Red Green "This is only temporary,Unless it works!"

97 E300D 157000 miles
87 300TD ?141k? miles

'Just replace the #2 (With a BOSCH GP)

When you've got lotsa time and a new intake gasket you can do them all.

The Pre-Glow relay on your 602.962 does not have an Aluminum 80 Amp strip
fuse inside the cover of the relay.
It is Electronic,it will "Sense" an overload and dis-connect as a Lifegaurd action,
until you correct the overload.

__________________
'84 300SD sold
124.128

OK.. Ordered 1 Bosch GP Part # 80031.
# 2 plug is relative easy to get to.. (We'll see). I'll take some pictures and post them. Should be done by the weekend.
Bob

__________________
92 300D 2.5L OM602 OBK #59

1992 300D 2.5 Turbo Diesel

If you have 1/4 sockets,swivels,extensions and patience. It is possible to replace them without removing the IM.

__________________
1999 E300DT (131,800) 154,000 Black on Black SOLD

2006 CLK 500 coupe Capri Blue on Grey (zoom,zoom)
47,000mi

04 VW TDI Passat 80,000mi
(Techno)

How to eliminate oil dependency through market-driven approaches.
“We could cut oil use in half by 2025, and by 2040, oil use could be zero,”
The Sound of Diesel Speed
Ode to MB

Let me say that #2 plug is a biach to get to. I've taken the cross-over intake tube off. I really don't want to take of the intake...But.... Any recommendations!!! #2 is about 1/2 out.

__________________
92 300D 2.5L OM602 OBK #59

If you mean the GP is unscrewed past all of the threads and stuck but not broken the tip of the GP may be trapped by Carbon build up. Soaking it over time in PB Blaster to penetrate and lube it may help.

If it is otherwise stuck I would do some careful reading of Threads concerning how to try to avoid breaking the GP off in the head.

__________________
84 300D, 82 Volvo 244Gl Diesel

After a good nights sleep. I reassessed the issue of getting the plug out. I didn't have to pull the intake. I used a long extension and attacked the plug from the back of the engine going towards the front. I was trying to attack the plug from the side, but the ALDA and fuel lines were in the way.
Coming from the back of the engine in the gap between the engine and fuel pump (parallel to the engine) worked. 1/4 in socket is what you need the 3/8 tends to be a little big.

Thank you PMARI for the suggestion. Patience worked. Thanks all for the tips.

__________________
92 300D 2.5L OM602 OBK #59

Just replaced all 5 this past weekend on my '93. Might not be everyones idea of "easy" but I removed the fuel lines and unbolted the cruise unit and set it aside. Using a ratcheting 10mm box wrench (seems like it was designed for this job!), they were pretty straight forward to get at.

Good luck!

Klaus

__________________
‘84 300TD “Mountain Goat”
'62 300d Adenauer-350 Chevy - "Max"
'15 VW Passat TDI
'16 Dodge Ram 3500 - Cummins w/6-speed
'68 Mustang fastback
'55 T-bird
‘63 Studebaker Hawk

This is a great thread and exactly what I was looking for.

Starting my 602 this afternoon after work, I noticed a slight stumble when I first started the engine. Don't recall the glow light turning on.

Was exiting the parking lot when the the glow light came on. Whoa, never seen that before. It turned off after a minute. I stopped and restarted the engine...same thing.

Then located document 15-4000 and learned about the FAULT capability.

Then started poking around here and found this pertinent thread.

Seems to be exactly my problem.

Tested the resistance of the glow plugs with my vintage analog ohm-meter.

#1-OPEN
#2-#5 Somewhere below 3 or 4 ohms.

At least I can see #1. Hopefully I can get it out/in w/o removing the manifold.

I'll look around town for a Bosch unit so that I can fix it this weekend. Kind of scares me to work on aluminum heads though. I always fret when I change the spark plugs on my aluminum headed gassers too.

Will regular spark plug anti-seize be OK? The kind they sell in the little packets at AZ?

Any tips will be greatly appreciated.

Thanks!

__________________
1993 W124 300D 2.5L Turbo, OM602.962
2000 Chevrolet Cavalier, 2.4L DOHC
2002 Ford Explorer, 4.0L SOHC
2005 Toyota Prius, 1.5L

http://www.fuelly.com/sig-us/40601.png

It really wasn't too bad. I did use regular anti-sieze. Haven't had to mess with it so I can't tell you one way or the other. But I only did the one (#2). Be patient with it. Also be careful not to over torque (snapping it) it getting it out. I think it is about 20 lbs.
Here's some great info:
http://www.w124performance.com/docs/general/glow_plug_info2.pdf

BTW I did not ream out my hole. I just did a R/R. (Remove and Replaced) the bad one.

__________________
92 300D 2.5L OM602 OBK #59

Thanks for the tips.

What would cause a plug to snap? Sounds pretty bad.

Beru makes the case for replacing all 5 at once, but I think I will only do the one for now.

__________________
1993 W124 300D 2.5L Turbo, OM602.962
2000 Chevrolet Cavalier, 2.4L DOHC
2002 Ford Explorer, 4.0L SOHC
2005 Toyota Prius, 1.5L

http://www.fuelly.com/sig-us/40601.png