I figure while I have this car apart for the fuel lines and such, I should do the glow plugs just in case. Is there any real difference in reliability or longevity of the oem plug vs the Bosch, who likely makes it and puts it in a Mercedes box for them?

Also, which reamer do you guys like the most? I figure plenty of time for some Kroil to soak down in the threads, and ever so slightly back and forth on the ratchet to get them out, it's worth doing now.

When I did mine I got lots of after the fact advice to use an impact gun and to have the engine full temperature.

Unfortunately I cannot remember what kind of GPs I used, and I have since sold the car to forum member TimFreeh and gave him all the receipts when I sold it to him.

OM606 glow plug change - one broke off

If you happen to break one pm me I have all the tooling to drill it out correctly without damaging anything.

And I have the reamer tool also if you want to borrow it let me know.

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The OM 642/722.9 powered family
Still going strong
2014 ML350 Bluetec (wife's DD)
2013 E350 Bluetec (my DD)

both my kids cars went to junkyard in 2023
2008 ML320 CDI (Older son’s DD) fatal transmission failure, water soaked/fried rear SAM, numerous other issues, just too far gone to save (165k miles)
2008 E320 Bluetec (Younger son's DD) injector failed open and diluted oil with diesel, spun main bearings (240k miles)

1998 E300DT sold to TimFreeh
1987 300TD sold to vstech

Glow Plugs breaking off is common so some people wait till they have had actual failures to deal with that.

The Beru Glow Plugs that are stock are supposed to be slightly better then the Bosch ones but due to cost and availability most people use Bosch. Beyond those 2 makes there is no recommendation.

Glow plugs failure increases due to out of spec conditions of combustion (in your case timing and Injector condition and of course engine compression) and carbon build up.

Glow Plug breakage is cause by corroded threads and or carbon leaked past the sealing area and filled in the cavity. The PB Blaster or many say Kroil helps with the treads but I don't think it will do anything for the ones trapped in carbon.

Use a never-seize type compound on the Glow Plug threads when the are installed.

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84 300D, 82 Volvo 244Gl Diesel

Does the impact driver recommendation apply to the OM606.910? I'm debating hating myself for deciding to replace the GPs... 258k miles, ~1k under my ownership, and no idea when it was last done 🤣.

I have an electric 1/4" drive right angle impact and I figured that would be perfect for lightly tickling off the glow plugs if they decide to go.

Stick with the OE Beru plugs. Not sure where Bosch are made these days

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Why I will never do business with "DieselKraut" again

http://www.peachparts.com/shopforum/mercedes-benz-used-parts-sale-wanted/378935-why-i-will-never-do-business-dieselkraut-again.html

I have had good luck asking eBay sellers that sort of info or sometimes when you page down in the text of the ad it has where they are made.

Note large sellers don't know what they are selling and won't take the time to look. Nor will sellers that are drop shippers.

I don't know if the Pelican Parts would look for you.

If you ask a seller a question you make sure the question and answer are saved in the correspondence area and the seller obviously did not describe it correctly you can get money back with "item not as described.

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84 300D, 82 Volvo 244Gl Diesel

I have read somewhere of Bosch Glow Plugs for my year are also made in India. However, since 2007 all of the sources I have received them from have Made in France on the box.

I am guessing that if you want to end up with a made in India Glow Plug buying it from someplace like Autozone would likely get you that.

Note I have not had large issue with Glow Plug failure but if I need to fill out an order to make the cost high enough Glow Plugs and Oil Filters are what I often buy do do that. I figure since the Glow Plugs are cheap to shop and prices are rising and where glow plugs are made seems to be going to India and China I figure I could always sell off the extras at another time.

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84 300D, 82 Volvo 244Gl Diesel

Correct. Bosch had outsourced a large % of older design components to India. Less complex to manufacture and they still use older MB engines in existing newly sold vehicles, so makes more sense logistically.

Not all Bosch is bad though. Mercedes Benz batteries for instance are supplied by Bosch/ Varta and are the best battery available (despite the 1 year warranty). I'm running on year 7 with mine.

I believe OE Beru plugs are still EU made. I also believe Monark is made in Germany.

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Why I will never do business with "DieselKraut" again

http://www.peachparts.com/shopforum/mercedes-benz-used-parts-sale-wanted/378935-why-i-will-never-do-business-dieselkraut-again.html

On my Year and Model the Monark glow plugs don't hold up. I started having failures after one year or so of use with them. I bought Autolite (the tips swell on those and you are lucky to get them out, my experience) and the Monarks before I knew better. Both the Autolites and Monarks were bought in 2007-2008 before there was such an influx if the India and China glow plugs.

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84 300D, 82 Volvo 244Gl Diesel

Looks like FCP Euro has the Beru in stock for $16.29 a piece and they state they are made in Germany. I have seen other guys say they've had luck with using impact guns to remove them, even on the F150s with those crappy 2 piece plugs that always break due to carbon build up, tons of guys just zip em out with a small impact. While that does make me nervous, I do plan on buying some Kroil and letting it soak for quite a while before trying. I haven't had any issues with cold starts (even when the car did run before I put it under the knife) and when I bought the car a couple years ago, the service manager at the Atlanta Mercedes dealership showed me where the plugs were removed, reamed out, and reinstalled. Perhaps since it's only been a few years, mine won't be that difficult to remove.

I wish I had the money to buy one of those sweet induction heaters or whatever they're called that'll heat the plug up and let me get it right out with a ratchet.

Well, 2 of the plugs came out with ease. The rest are ever so slightly budging, but I'm working them in and out with plenty of PB Blaster to lubricate things. I'm not forcing them, if one feels tight and only wants to move a tiny bit, I consider it a small victory, spray it, and will just come back to them tomorrow. Do they make a lubricant or spray that just dissolves carbon? Cuz that'd be awesome. I ordered one of those magnetic heat inductor things but if I can successfully remove these without it, I may cancel the order.

I had 6 MB glow plugs installed and one went out in 4 years. I believe they were made by Bosch. Pelican lists Bosch as the OEM. When the MB plug went out I had 6 Berus installed. I have about 4 years on them so I don't know if they are better or not but I am hopeful.

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'97 E 300 D

I heard that 1/2 ATF 1/2 acetone makes the best penetrating fluid.