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Longer glow plugs

Discussion in 'Engine, Drivetrain, Fuel and Exhaust' started by BORNJOYFUL, Nov 7, 2012.

  1. BORNJOYFUL

    BORNJOYFUL Senior Member

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    Your Mercedes:
    1992-3 k reg 300td , 603 engine
    I run a 300TD 1991 and a 2.5 190d on 100% veg oil and every year the cheap glow plugs need replacing.
    I am considering Bosch duratherm but wondered if i can get a recommendation for ones that will fit both cars which are longer
    TIA
     
  2. wireman

    wireman Senior Member

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    Your Mercedes:
    nice 201 2.5D 1993 & very nice 129 SL500 1994
    At a guess I would say NO NO NO.

    The 601/2/3 engine underwent changes to its cylinder head design at least twice and different combustion chambers, injector nozzles and glow plugs accompanied each re-design, the second re-fit also involved shifting the injector angle to markedly reduce emissions.
    The glow plug is specific to the combustion chamber, its end tip must lie in exactly the right place or it will either not work efficiently or will prematurely fail, the glow plugs do have an effect on the engines normal running since they are continuously heated by the combustion process, too much of this will burn them, too little will make the engine less efficient. Too long a plug might just smack into the other side of the chamber making for a nasty mess in addition to them slightly raising the compression ratio.

    Are you sure you have fitted the right plugs, to my knowledge there is not normally a great deal of difference in glow plug life when running funny fuel, its worst drawback is spoiling the lubricating oil and hence running the risk (certainty?) of reducing engine life, gummed up piston rings are I believe a fairly common problem.
    Diesel fuel runs slightly hotter than the funny stuff and I would speculate the effect to be that veggie plugs are less prone to burning.

    Personally I am not much in favour of veggie, there is a clue in the names, diesel engine & diesel fuel, its simple really.

    You must fit the correct plugs, you have already found out that cheap plugs are no good, quote your chassis or engine numbers at MB.
     
    Last edited: Nov 7, 2012
  3. spock500

    spock500 Senior Member

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    Bosch Duraterm are good especially for veggie engines.

    I have used them in both my OM605 & 6 without issue, never had to replace them either.

    The ones to go for are the chromium variant although these were in short supply at one stage.

    [​IMG]
     
    Last edited: Nov 8, 2012
  4. SilverSaloon

    SilverSaloon Active Senior Members

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    w124/1994/om606
    yes duraterms on both my 606 cars. only had 1 go dead in 2 years running 100% veg
     
    Last edited: Nov 8, 2012
  5. OP
    BORNJOYFUL

    BORNJOYFUL Senior Member

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    Your Mercedes:
    1992-3 k reg 300td , 603 engine
    I know from last year they took the same cheap plugs and on ebay it seems like the GLP006 fits both but the GLP001 only fits the 200d-
    but I have no idea which is longer and hence more heat
     
  6. wireman

    wireman Senior Member

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    Your Mercedes:
    nice 201 2.5D 1993 & very nice 129 SL500 1994
    In the later MB update C~1989-90, along with 180 degree rotation of the combustion chamber and 5 degree injector inclination to improve swirl, a shorter glow plug was installed, "to improve cold start".
    It does not follow that there is more heat from a longer plug, just where in the chamber the hot spot is, I say again fit the correct length of plug as it was designed and tested to perform optimally, the hot spot must be in the right place (point of maximum swirl) or you might as well just not bother having glow plugs in.
     
  7. lwbnick

    lwbnick Senior Member

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    Is not the solution to stop buying cheepo plugs off ebay and just buy some proper ones from MB?

    It's not like their expensive from Mercedes, having to change cheap ones every year is a false economy.
     
  8. OP
    BORNJOYFUL

    BORNJOYFUL Senior Member

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    I am trying to buy duratherm - maybe even the chromium if i can find in the UK - not the cheap ones. thats the whole point of the post.maybe you misread.
     
  9. OP
    BORNJOYFUL

    BORNJOYFUL Senior Member

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    1992-3 k reg 300td , 603 engine
    OK more glow questions-
    not sure if I do have one out or not.

    if i turn on my ignition without starting , no glow plug light comes on until relay kicks/ clicks in at about 30 seconds then the yellow glow plug light stays lit for about another minute and then goes off .My headlights do not change at all!
    I was told you can tell how long your plugs are heating this way as duratherm need one and a 1/2 mins -

    here is the quote from another forum where people were askign about how long their timer stays on for the afterglow in assessing whether the duratherm need a different glow plug timer -

    << An easier way of doing it is to put your lights on and get ready to start normally at night.After the glow plug warning light goes off - don't start, just sit and do nothing (I am really good at this) and a while later you will hear a click and the lights will get brighter, as the heaters let more power go to the lights when they stop.
    You can use this to see how long the afterglow is without using any kit>>
     
  10. wireman

    wireman Senior Member

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    Your Mercedes:
    nice 201 2.5D 1993 & very nice 129 SL500 1994
    You have one or more glow plugs not drawing current, this will likely be a duff plug but a bad wire or a fuse internal to the glow control relay may also be the cause.

    The Duratherm plug has a dual element, one coil in the tip does the heating and is built such that it rapidly heats, the second coil is behind the heater and is temperature sensitive such that as the plug heats it tends to cut the current to prevent over heating.
    These plugs heat to 1000c or so in about ten seconds, a standard plug will take about 30 seconds, only achieving ~500C in 10sec.
     
  11. OP
    BORNJOYFUL

    BORNJOYFUL Senior Member

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    So how is supposed to look on the dash as long as all glow plugs working?

    Is it propable that both the 300TD and the 190D can take the same chromium duratherm.
    They absolutely DID have te same NGKs

    The regular duraterm seems to come as the 001 and the 006 thats what confusing me.

    plus the fact that there does not seem to be places i can get info online nor buy them!!
     
  12. OP
    BORNJOYFUL

    BORNJOYFUL Senior Member

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  13. wireman

    wireman Senior Member

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    nice 201 2.5D 1993 & very nice 129 SL500 1994
    Turn on, the glow lamp illuminates, wait 'till it goes out and start up, the lamp will extinguish early if you start it early (but it might run like a bag of bricks and blow out blue smoke for a few seconds), no further illumination of lamp should occur after starting.

    The glow system is detailed in the US 190 manual.
     
  14. OP
    BORNJOYFUL

    BORNJOYFUL Senior Member

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    oh yes, thanks Wireman- I seem to remember that used to happen.
    :(
     
  15. spock500

    spock500 Senior Member

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    300TD, 1998
    Try these guys http://www.helptoday.co.uk/automotive/engine-spares.asp
     
  16. OP
    BORNJOYFUL

    BORNJOYFUL Senior Member

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    Finally sorted it out. The Chromium were withdrawn from the market so it is only Duratherm that are available.
    The 190d and the 300td will take GLP001 or bosch 0250201038
    the 300td will also take the GLP006

    I got mine from Saber autospares on 01214599999 - cheapest I could find at £7 inchl the postage
    they are sending me 11 of them for £62 which is only approx £5.65 each and that includes the postage!
     
  17. chizzel89

    chizzel89 Senior Member

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    Your Mercedes:
    Mercedes-Benz C250 Turbodiesel Sport Auto. Estate. 1998. 180,000 mls
    I find Beru and Bosch Duraterm are much of a muchness in terms of longevity. The plug which was sheared off in my Mercs cylinder head was a Duraterm and was 8 years old and still working, despite being sheared off!!!
     

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