Glow plug removal difficulty / questions

Hi Folks,

I got a check engine light a few weeks ago and it was a glow plug code (forget the exact code). After doing some reading on the forum I decided to just clear the code and then replace all the glow plugs as a routine maintenance measure since I purchased the vehicle with 108K and don't know much of the history (~117k on it now). Then I figure I'd see if the code came back and take it from there..

Anyway, after getting the vehicle to operating temperature, I gently broke all the plugs loose and then began removing them. They looked good although I didn't notice any never-seize on the threads. However, when I got to the 4th plug from the rear, I was able to unthread it about 1/3 the way out before it started to bind up again... So, I sprayed copious amounts of PB Blaster and worked it back and forth but no dice it still binds up about 1/3 of the way out, fairly abruptly.

Sooo, I just ran it back in and snugged it up and replaced the other 4 plugs. Any ideas on what I might do next? For now I'm willing to just let it be but sooner or later I figure I will have to deal with it.. Then what? (Not to mention knowing it is there is going to mess with my mind )

TIA for any suggestions!
Jeff

I also had a question. I have a 2004 Sprinter I have had for over 100K miles, bought it with 100K miles. The glow plugs are original, I am sure. I don't have any light in dash. Do glow plugs just work or don't work, any need to replace them at over 200K miles if there are no check engine light?

OEM Glow plugs (also bolts) are nickel plated from factory, that acts as a anti seize.
Your glow plug is not seized at the threads, that is why you can unscrew it a bit, what happens is that the tip of the glow plug have formed a crust or it is a bulge on it from carbon deposits, so you will have to try to screw and unscrew many times to try to crack it, do it gently, or you could end up with a broken glow plug inside the head. It might help to spray something from the intake to wet the tip of the GP.

aspen said:

I also had a question. I have a 2004 Sprinter I have had for over 100K miles, bought it with 100K miles. The glow plugs are original, I am sure. I don't have any light in dash. Do spark plugs just work or don't work, any need to replace them at over 200K miles if there are no check engine light?

Click to expand...

Hi Aspen, do a resistance test with a multimeter, and you will know.
check for it on youtube, the most amazing source of knowledge and stupidity at the same time.

aspen said:

I also had a question. I have a 2004 Sprinter I have had for over 100K miles, bought it with 100K miles. The glow plugs are original, I am sure. I don't have any light in dash. Do spark plugs just work or don't work, any need to replace them at over 200K miles if there are no check engine light?

Click to expand...

Whether to replace the glow plugs periodically or wait until failure is a poser.

As long as the glow plugs are working there is no real reason to replace them.

The longer the glow plugs remain in service without being removed, the more likely they are to seize and give trouble during removal attempts.

Sometimes removing the the glow plugs causes damage which is not easy to repair.

If the glow plugs are seized and don't burn out then just being seized of itself isn't a problem.

So after 200,000 miles of service is it better to let sleeping dogs lie, or be proactive and remove the glow plugs so they don't seize more.

One thing that I will say for certain is that should you decide to remove all the glow plugs I would replace them all regardless of what tests for resistance or any other other tests reveal. Once a high mileage used glow plug is out do not re-use it.

Anti-seize is not generally recommended. One reason is that it changes the correct torque value. Some do recommend using ceramic grease. I don't believe that MB supports that idea.

vic

After running some seafoam through the engine (via the gas tank) to possibly help remove some carbon from the glow plug I gave removal a few more attempts. When I finally did get it out the center sections of threads on the GP were gone and of course the cylinder head threads were pretty much trashed. I chased them and now a new glow plug is seated by maybe two threads at the very bottom.

Question, looks like the time sert kit is the way to go but $250 seems like a lot to fix one set of threads (though I guess not a lot when compared to the other possibilities).

Anyone have a used time-sert kit they would like to sell or rent?

Thanks!
Jeff

Sprintophilic said:

... When I finally did get it out the center sections of threads on the GP were gone and of course the cylinder head threads were pretty much trashed. I chased them and now a new glow plug is seated by maybe two threads at the very bottom.

...
Thanks!
Jeff

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Not that you asked...

There have been others who had thread damage and just replaced the glow plugs without using thread repair kits. I don't recall any posts of replaced glow plugs rocketing out of a 5 cylinder engine. There is risk, but it may be better to let sleeping dogs lie.

vic

Jeff
I use time serts for this application all with success I might add!
All you need to buy is the one kit for 10x1 mm size; it has everything you need,
I buy these kits fairly frequently and use a Snap On square drive socket set especially made for thread taps in the MV repair industry to do the job.
This is essential because there is often no room to use a conventional tap holder to cut the threads. Nor insert the insert I might add!

The one side time sert for your application is about $60, the same goes for the square socket drive set.

I buy these from AAA Metrics on 444 Lipan St in Denver, my friend Richard the owner usually has these in stock as well is the 8mm for the V6 engine as well.
www.aaametric.com

I am sorry but I don't lend tools.
As a Frenchman (Pro Mechanic) I once worked with outside Lille in France -Gitane ciggy in the corner of his mouth said in Gallic words to the effect of.
Tools and motorcycles are like your wife or girlfriend--I never borrow you must never lend!
Best of luck & Merry Christmas
Dennis

Hey Dennis. May sound like a dumb question. But what happens to the metal that drops into the head while cutting the threads ? Is it just small enough that it melts upon ignition?


Howboutcha-

Well you are supposed to put a dummy injector in the head and apply a constant flow of air into the cylinder and the escape through the work area will expell any bits of swarf falling into the cylinder.

That stated I am always looking to reduce the shop time--Sooh--
I often just plug the hole deep down with a shot of grease, do the job; then crank the engine over often firing the beast.
The expell of compressed air from the engine blows the grease plug out, swarf bits 'n all!

A clean up with some brake cleaner and further cranking purge out usually cleans the carbon from around the glow plug seat (plus a shot blast of shop) air usually cleans it enough the insert the glow plug and then yur dun!
Dennis

Well lucky for me I only have to do the first two plugs the others came out nice n smooth. That dab of grease sounds like a winner. I surly doubt want to pull an injector if I don't have to. But maybe I can use another glow plug hole to send compressed air through while I'm cutting. I'll have to kick it around i guess b


Howboutcha-

Here is a pic of a new glow plug and cyls 1-4 that came out (Cyl 5 plug went back in to cyl 4).


The new glow plug for cyl 4 would not "grab" I believe because, if you look closely, the leading thread is beveled rather than a clean cut like the old ones. I tried a couple of times. The new plug would just spin but an old plug would seat after a turn. So yes, I believe #4 is seated by perhaps a single thread.

So plugs 1, 2 & 5 looked great. Plug 3 has what looks like corrosion on the metal while plug 4 had much more carbon on it. Maybe the seafoam cleaned some carbon off but that's how it looked when it came out. Were plugs 3 & 4 worse because they had not been changed when the others were, perhaps? Only have 120k on the clock.

Dennis, is this the kit you were referring to: http://www.amazon.com/TIME-SERT-Met...qid=1418905989&sr=8-2&keywords=time-cert+10mm

I thought maybe the inserts should be the copper colored as in the $250 kit: http://www.amazon.com/M10x1-0-Glow-...8-1-fkmr1&keywords=time-cert+glow+plug+thread

I also thought about just purchasing the inserts and piecing together the boring and tap tools:
http://www.ebay.com/itm/Time-Sert-4...1261770288&pt=Motors_Automotive_Tools&vxp=mtr

Thanks a lot for everyone's input.
Jeff

Jeff
The spendy time sert kit you have illustrated has the guide drill tool adapter to ensure you cut the hole dead square. It is possible to render the head as scrap by carelessness since it is possible to cut a repair thread hole in the head "off center" and then the glow plug wont seat on the tapered section. I have seen some horrors where a previous operative has then forced the glow plug in thus bending it! The combustion carbon/gases in most cases will propagate up into the tubular cavity as you have with Glow #4 and coke it all up with possible re-ejection of the plug!

The timesert requires that you cut a new hole-(obviously.)
When you cut the thread use something like kerosene as a cutting lube medium so that you don't gall the new threads,
Then you counter bore it with the face cutter mandrel which in effect forms a shoulder.
The insertion tap inserts the "insert" but at the same time swages the part into the parent threaded portion of the hole.
This of course ensures that it stays put during future glow plug removal.

By buying just the inserts alone and trying to do a repair job without the tools essential for ultimate repair success leaves you exposed or at risk of making an expensive mistake.
Dennis

Sprintophilic said:

...

So plugs 1, 2 & 5 looked great. Plug 3 has what looks like corrosion on the metal while plug 4 had much more carbon on it. Maybe the seafoam cleaned some carbon off but that's how it looked when it came out. Were plugs 3 & 4 worse because they had not been changed when the others were, perhaps? ...
Jeff

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If the glow plugs were properly seated when the Seafoam was introduced it would never get to the intermediate chamber to affect the glow plug bodies.

The soot on number 4 could have been from running the engine with #4 loose, or if the seal seat face was leaking. I would closely inspect the seal face on the number 4 GP.



One thread as you mention does seem pretty dicey.

vic

Added.

Not that you asked...

Jeff,
If you buy the expensive kit you may be able to recoup some of the cost by offering it for rental. (Get a substantial deposit up front.)

Vic
I am surprised he got it out intact!
With my luck it would have busted off insitu, defied all attempts to pull it out and off would have come the head for a spark erosion removal job!
Cheers Dennis

lindenengineering said:

Vic
I am surprised he got it out intact!
With my luck it would have busted off insitu, defied all attempts to pull it out and off would have come the head for a spark erosion removal job!
Cheers Dennis

Click to expand...

Dennis,
I agree. It took patience, skill, and dose of luck for that one to come out intact.

vic

What you guys are saying makes even more sense, now. While I have some significant experience with car and motorcycle engines I have no experience with diesels. Soooo, I had no idea that the GPs sealed at the bottom taper. The bottom taper on GP4 has some carbon on it. Makes me wonder, Vic, if GP4 was inserted with bad threads and maybe never seated well to begin with as you implied.

Regarding the time-sert kit. I think the $250 is probably worth it at this point. Clearly they sell a lot of kits in the $100 dollar range so it reasons that this one is prolly a buck-fifty more special. I guess I'll just bite the bullet rather than creating a new bigger headache.. Heck, maybe I can just resell it to the next guy on the forum who needs it or ebay, whatever.. (I'm sure if I found someone with the kit the minimum charge would be at least $100 anyway.)

And yeah, this was about as patient as I've ever been with something and still I ran out of patience and got lucky. I think out of the 4 different attempts I made to remove it I was breaking more if the seized threads apart. In the end I was pulling the free-spinning plug up by it's tip with pliers as I rotated it counter-clockwise when it all of a sudden it just came out. I know there were some thead pieces lying around so I used a shop vac and then stuck a magnet down the hole and picked up a few more particles. Hopefully the motor blew out whatever was left