Glow Plug Advice

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Mon, 04/03/2013 - 12:50
Simon666
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Hi.. Had a new set of glow plugs in about 6 months ago - along with the relay (which I got just in case so now have a spare!) Anyway, it looks like one or more of the plugs has failed - dash light does not come on - starting takes a good crank - lots of blue smoke for a while etc. Checked the dash bulb and that is fine (I swapped a couple over to make sure). The garage have said to bring it back and they will renew at their cost - They have asked if I can check if there is anything unusual about the plugs for a 1985 300GD 617 engine they should be aware of - specifically having a voltage change from the usual set up - they thing it has 9 volt ones in currently, as clearly such a quick failure is unexpected and they want to make sure they get the right ones. They are going to look the entire system over again just in case it is something like the ignition switch, however the symptoms - elongated time that the glow light was on - slightly rougher starting, makes me sure its the plugs?? So any thoughts/spec on the plugs - it had decent german ones in, hence the puzzlement. Ta Simon VIN 46033227037112
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Mon, 04/03/2013 - 14:37
#1
Pistonhead
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Re: Glow Plug Advice

My suggestion would be to get dealer supplied glow plugs, you will need your engine number and chassis number for there is quite a choice in glow plugs available. Secondly, get your garage to ream the glow plug holes before fitting the new set. 

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Tue, 05/03/2013 - 00:03
#2
gav.helme
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Re: Glow Plug Advice

Hi

Two types for the 12v engined OM617

Yours are easily the later type if it has its factory engine fitted

Part Number A000 159 81 01 they are £12 each plus Vat and MBUK have 10 in stock

Cheers

Gav

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Tue, 05/03/2013 - 09:33
#3
Simon666
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Re: Glow Plug Advice
Many thanks guys. (and Peter who pm'd me) I will get them to order the ones suggested. The engine is remanufactured from Crewe engines, but is identical to the original 1985 unit, so I'll get the guys to order the right plugs up. Let's hope it's that Ta Simon
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Tue, 05/03/2013 - 22:25
#4
gav.helme
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Re: Glow Plug Advice

Hi Simon

Have you got the engine number from the engine the Crewe supplied?

Just so i can double check.

From memory the two types were as follows....

Early type plug A000 159 61 01 £23.40 Each - Open Wire Type

http://www.ebay.co.uk/itm/Mercedes-Engine-Diesel-I4-OM621-Glow-Plug-A0001596101-/290754972067?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item43b258c9a3 

Late type plug A000 159 81 01 £12.00 Each - Closed Pencil Type

http://www.ebay.co.uk/itm/Mercedes-Benz-Diesel-Fuel-Glow-Plug-Heater-Plug-A0001598101-/320901581475?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item4ab7398aa3 

The Glow Plug Relays are either the early A001 545 35 32 (A001 545 22 32) or the late like yours should be A001 545 98 32

The only real difference in systems is the early type plugs are linked together across the engine with a series of wavy thick wires with ceramic insulators and the later type plugs are just linked with part of the main standard wiring loom

Hope this helps

Gav

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Tue, 05/03/2013 - 23:21
#5
Simon666
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Re: Glow Plug Advice
Hi Gav I know the ones in it are the late type, as they were on the original engine as I checked out a YouTube vid of the conversion to avoid completed glow failure if one goes down - which is what happens with the wavy wire version as I am sure you know. So 100% certain it is the later type fitted, together with the later relay (we put the new one on just to be safe) still wondering if it is an issue with the live feed from the ignition to the relay as there is no glow light tell tale at all on the dash. So will get that checked before getting the plugs. Always glad of any advice and will be in touch about those parts as well. My G is feeling its age :-) mind you it is still starting, just lays down a lot of smoke for the first few mins! Many thanks Simon
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Tue, 05/03/2013 - 23:33
#6
axel
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Re: Glow Plug Advice

the  glow units glow on for about 23 seconds after the engine starts to give better cold performance and reduce emissions ,the glow light will not come on if there are glow plugs that have failed ,the engine will start and run roughly (nailing and smoking) and then the yellow light will come on indicating  faulty glow plug(s). hope this helps.

 the glow light is operated by the sensor on the engine block which operates the time that the light on the dash is on for ,the light goes out then you can start the engine but the 'afterglow' goes on for 20+ secs, the operation of all this needs testing along with the continuity of all the glow plugs .

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Mon, 18/03/2013 - 23:08
#7
Simon666
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Re: Glow Plug Advice
All sorted. It was two failed plugs (new 3 months ago so all replaced foc with genuine Merc) Odd though that the glow relay never came on until the new plugs went in.. I.e it did not come back on After it had started, to show failed plugs, just simply stopped coming on. So my guess is you can have one plug out and the light still comes on, but obviously for longer, but two out and no light. Thanks again for the comments and advice. At least it turned out to be a simple fix this time Ta Simon
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