Hi Guys
Anybody got any comments on using grease or any other compound on glow plug threads. I need to replace 1 glow plug on my 605, 5 cyl. 2.5l, Alloy head, in a W202. Ive used a product called Copaslip (in the UK) on outdoor threaded parts and it does stop them siezing up. Its a copper based "grease", but how would it do on an aluminium Cyl head ?. Any comments greatly appreciated.
Peter

I am using anti-sieze on my glowplugs. Not sure of the formulation, but I can check. So far I've only replaced glow plugs on the 1987 300D with aluminium head. I'd use the same compound on the iron head 1982 300D as well.

Ken300D

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1982 300D at 351K miles
1984 300SD at 217K miles
1987 300D at 370K miles

Lubro Molly makes an anti-seize paste that is fantastic.

How's that for digging up an old post?

autozone carries the loctite brand of antisieze. its a pretty big bottle for about $8

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have no worries.....President Obama swears "If you like your gun, you can keep it

Add the airfare from Scotland and it gets pretty pricey.

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1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

copper and AL dont like eachother, and the al courrodes from the bimetalic reaction...

Hows that for 9th grade science?

Anyways I dont really know what u can get in scotland

~Nate

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95 Honda Shadow ACE 1100.
1999 Plymouth Neon Expresso. 2.4 swap, 10.5 to 1 comp, big cams. Autocross time attack vehicle!
2012 Escape, 'hunter" (5 sp 4cyl)

Since the threads conduct the ground side of the electrical circuit you are supposed to use an anti-seize formula which will is specified to conduct electricity, those are the copper based formulae and they are the most costly types available...make sure you don't use an electrically insulating anti-seize compound.

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Marty D.

2013 C300 4Matic
1984 BMW 733i
2013 Lincoln MKz

o wow i didnt notice that.

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have no worries.....President Obama swears "If you like your gun, you can keep it

Hogwash!
The threads in mating metals contact each other and make good electrical connection regardless of whether one uses an insulating grease or not!!

One Glow plug manufacturer recommends not using antisieze (without defining whish type of antisieze). I assumed it to mean the grey silvery anti sieze which is made from Molybdenum disulphide. I have used that stuff for glow plugs for years and never had a problem. So last time I had a job on my present 603 engine I used the copper-based antisieze. Now I am not so certain that was the right decision but I won;t know for a few (hopefully many) years.

Actually there is antisieze material made for aluminum called NO-OX-ID. It is employed in the electrical field to prevent the oxidation that occurs in aluminum wire. Aluminum wire was banned in the US for use inside houses but it is still used for high current leads such as drops from a power source to the point where it is metered and in big industrial applications where weight and cost can be reduced by using aluminum.

I suspect No-Ox-Id is available in Scotland from a good electrical supply house (presuming aluminum wire is used there also - I just don't know for sure!)
see: http://www.chem.hawaii.edu/uham/conduct.html

I have a tube of Sanchem material I bought off eBay. I believe that it will prevent possible GP oxidation in the aluminum OM602 and 603 heads used in later diesels. In the iron head (617) engines it probably doesn't matter much what is used, if anything!

BTW, stuck glow pugs seem to be more common in the aluminum head engines and use of a anti-sieze is probably much more important with that type of engine, but in any case if there is a bunch of carbon that has coked onto the GP it will prevent the plug from coming out and can result in having to remove the head if a GP breaks off. I think this is a more nefarious problem than you think, because if you can't see it and just because the threads come loose on a plug don't wrench it out if it hangs up on carbon inside on the shaft of the plugs.

A local mechine shop had a recent MB diesel (2003?) that a mechanic at the Mercedes dealership broke a plug off in, it was a real long thin GP unlike the ones in the 602/603. Maybe that makes them more prone to breaking off? Whatever, it cost somebody big time to get that one out!

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'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!

I dont think antisieze is necessary on the glow plugs.

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1981 300D 147k
1998 VW Jetta Tdi 320k
2001 Dodge Ram 2500 141k
1979 300D 234k (sold)
1984 300D "Astor" 262k(sold)
Mercedes How-To and Repair Pictorials
I love the smell of diesel smoke in my hair

NOALOX sold at Home Depot or probably any hardware store is a anti-oxidant joint compound for electronic parts.

It "Reduces galling and seizing. Promotes good ground through the joint"

Voltage rating 600 V. Good stuff I use it all the time.

Danny

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1984 300SD Turbo Diesel 150,000 miles

OBK member #23

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If you have a sealed up non-leaking engine its almost a necessity if the glow plugs will have to changed later on in the life of the car.

On the 6 cylinder engines, its wise to use SOMETHING as half the time the plugs break off in the head.