Glow plug replacement questions

Thanks for your quick reply. I would say that it is not loose at all as it barely clicks. An ohmmeter test implies that the plug is good so I am going to leave it. The main culprit here is the controller.

I will also post in NCV3. Thanks!
 

cacaw

Well-known member
...BTW, a defective glow plug can damage a new replacement module-so don't replace a specific single glow plug based on DTC info-then find the problem is still present -then replace the module only to have the undiagnosed defective glow plug destroy your new module. Doktor A
Does that hold true with the newer control modules too? I was hoping to skip the testing and go directly to replacing the control module and then see if that fixes it before replacing any glow plugs.
 

sikwan

06 Tin Can
In my mind, the warning is for failed glow plugs that fail shorted.

From my little experience, the glow plugs fail open and do not cause damage to the control module.

However, why take the chance? It is very easy to measure glow plugs for failed shorted or open. If they failed open, then you can do your control module replacement. If they failed shorted, I wouldn't plug in the control module. I would replace all the glow plugs first.
 

cacaw

Well-known member
... It is very easy to measure glow plugs for failed shorted or open. ...
I guess I'm just getting impatient and didn't want to have to bother testing them. It looks like there are two tests, using either a fuse or a multi-meter. I'll read up on that.

A friend told me about a decent Sprinter mechanic here in Ventura but I'd almost prefer to try extracting the glow plugs myself, because I can spend a few days getting them loosened up. With about 60,000 miles on our 2006 camper, maybe it would be a good idea to replace them all anyway so that I can put some anti-seize on them. But then, there's also the sage advice to leave well enough alone and only replace what's broken.
 

cacaw

Well-known member
...It makes no sense to not change it all out since it's only $50 for five good quality, brand new, glow plugs.
I ordered the kit (5 glow plugs and the control unit) from Europarts-SD, so I'll plan on just changing everything out and keep my fingers crossed that I don't break one. It sounds like it's hard to go wrong if I follow all the advice to go slow and limit the torque as I remove them.
 

Patrick of M

2005 T1N 2500 (NA spec)
It's the twist as well. Metal has elastic properties, and like elastic if you stretch it too much it breaks. That is why impac drivers work so well, after each hit the tension/stretch is released.
 

cacaw

Well-known member
My worry was for nothing. But, if I hadn't been worried enough to gingerly loosen and retighten each plug things might have turned out differently.

Looks like I was making a mountain out of a molehill. My glow plug kit hasn't arrived yet but I got impatient and took a stab at removing the glow plugs. The clips came off easily with a narrow pair of needle-nosed pliers and the first glow plug I tried (#2 seemed to have the best access) came out smoothly. The next one was giving some resistance so I sprayed some PB Blaster and warmed up the engine to 170º. Without waiting for the engine to cool, I removed the remaining four glow plugs without exceeding more than about 15 Nm of torque (guessing).

Ironically, it looks like getting at the bolts that hold down the control module might be tougher than removing the glow plugs. :)
 

rollerbearing

Well-known member
Cawcaw,

You recently had an engine rebuild didn't you? Did they remove the plugs at that time? Just wondering if they came out relatively easily because they hadn't been in terribly long?
 

ElJefe69

New member
After reading so much about it I finally decided to tackle the glow plugs on my 2003 om 612 2500 with 150k miles. Just wanted to drop an encouraging post to say it is possible without taking everything apart.

I squirted some kroil into the plug wells and let it sit over night then went for a drive and immediately got to work. 1,3, and 5 came out smooth and easy. 2 and 4 required some working back and forth and some wiggling with the needle nose pliers.

My tool of choice was a 3/8 snap on ratchet with a 6 inch wobble extension and an adapter to a 1/4 drive 6 point 10mm socket.

All tools pictures below. Thanks for all the info!
 

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fhuang1

New member
Ok. Took almost half day to get down to the last page.:)everyone is about taking it out. some says bosch has expensive reliable, updated one; some says us made is okay. First time to be on the safe side. I will try to take it out, 110k is about time.
 

jmwgoff

New member
BTW, a defective glow plug can damage a new replacement module-so don't replace a specific single glow plug based on DTC info-then find the problem is still present -then replace the module only to have the undiagnosed defective glow plug destroy your new module. Doktor A
Possibly a dumb question, but is the opposite true? Can a defective module damage new glow plugs? I just replaced my glow plugs and am wondering whether the module can do any damage to them if it's shot. If so, I may need to rush order a module from europarts before my trip next week...
 

kkanuck

LUV my T1N
Possibly a dumb question, but is the opposite true? Can a defective module damage new glow plugs? I just replaced my glow plugs and am wondering whether the module can do any damage to them if it's shot. If so, I may need to rush order a module from europarts before my trip next week...
I do believe a bad GP relay is incapable of harming a good glow plug, only the other way around. But if the relay is bad, even after a new GP, you will still show a fault as the relay cannot supply the glow plug with power if defective, so you will still get codes.
 

Nautamaran

2004 140” HRC 2500 (Crewed)
Possibly a dumb question, but is the opposite true? Can a defective module damage new glow plugs? I just replaced my glow plugs and am wondering whether the module can do any damage to them if it's shot. If so, I may need to rush order a module from europarts before my trip next week...
The original module has “fusible links” within that will melt if the glow plug shorts to ground, which simply cuts power. It won’t damage the GP.
The blown links can be replaced with 20-amp mini-ATM fuses if you’re handy (pictured, #1 good, #2 blown, #3 repaired), but for $100 the “new style” gp module is good value and has self-resetting breakers, not fuses, so will survive a shorted GP.
1620344984612.jpeg

There’s a butyl gasket on the plug side of these modules... once scraped off the circuit unclips and slides easily out of the enclosure box. A bead of sealant glues it back until next time. Others have run wires out to an external fuse box, but for the money you’ll spend on a 5-way fuse box you’re better off with the new module type. Or for ~$10 in materials there’s space within the box for five of these mini fuses. :thumbup:

-dave
 
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fhuang1

New member
Replace mines @ 100k, no issue, some rust on tip portion. Put in blue to see whether it gets better. Will check 30k
 

LowBudgetT1N

Active member
Got tired of an intermittent CEL with random glow plug codes. Replaced all 5 today, 2006 with 110k miles. Went smoothly thanks to all the tips and tricks posted here.
 

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