W211/S211 Bizarre Glow Plug Behaviour?

[Mintyfresh77]

Chassis: S211
Engine: OM646 Evo
Year: 2009
Mileage: 119m

So on some of the cold mornings recently the car was reluctant to start in the usual fuss free way but after some perseverance spluttered into life. I figured something glow plug related so hooked up icarsoft MB v2 to see if anything obvious was being reported and it noted cylinder 3 output stage (no signal) which I interpreted to be a duff glow plug (Yes I know Star would tell the whole story but I don't have that).

As I have only recently acquired the vehicle and don't know how old the current glow plugs were I went ahead and got a new set of the correct NGK plugs from the local stealer in the hope I could fluke a quick fix and GP service in one go but before I fitted the new plugs I visually tested the old plugs out of the cylinder by connecting neg lead to thread of the plug and engine block and used the normal plug lead for power now here comes the bizarre bit.

When I turned ignition on and watched the dashboard glow plug light go out after a few seconds I watched the glow plug in the engine bay and no sign of life so I turned ignition off and almost immediately the plug glowed into life briefly and then slowly faded off. Baffled I tested another cylinder and exactly the same, I then tested new plugs and exactly the same result so the plugs are effectively glowing into life at totally the wrong key/ignition stage. Is this a characteristic of relay/module failure?

I hope not because when I asked the dealer about a new glow plug module they said it's not made/supplied anymore!!!

Any words of wisdom welcomed!

 

[W1ghty]

My first guess would have been if the glow plugs are working then it’s either glow plug relay or car battery ?

 

[OneForTheRoad]

Put a strobe light on , the timings out .

Id suspect the relay seeing as it controls glow plug power. Plenty of relays on ebay etc . Mb talk crap.

 

[OneForTheRoad]

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For example.

 

[Mintyfresh77]

My first guess would have been if the glow plugs are working then it’s either glow plug relay or car battery ?

Glow Plug Relay fits MERCEDES CLC220 CL203 2.1D 08 to 11 OM646.963 A0005453516 | eBay

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For example.

You are diamond, thank you good sir

 

[johnsco]

I can't believe that MB don't supply the GP relay any more.
If not - There are loads of after-market ones around.

I'd enquire with MB of Newcastle.
They have dealt with all my queries very possibly.

The above recommendation (Post #4) is from Car-Parts-in-Motion.
I've used them before and they are pretty good.

 

[Mintyfresh77]

Glow Plug Relay fits MERCEDES CLC220 CL203 2.1D 08 to 11 OM646.963 A0005453516 | eBay

Find many great new & used options and get the best deals for Glow Plug Relay fits MERCEDES CLC220 CL203 2.1D 08 to 11 OM646.963 A0005453516 at the best online prices at eBay! Free delivery for many products!

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For example.

Darn it, Looks like this Febi part No doesn't correspond with the MB parts dept no which was A6461532579

 

[m80]

Is it possibly an earlier number?
Check here, it should show original variant and later updates.

Mercedes > Mercedes EPC Online > nemigaparts.com

Parts catalogs. Spare parts catalog Mercedes EPC Online. Mercedes.

nemigaparts.com

 

[OneForTheRoad]

Very expensive these for some reason . Might be worth a trip to a garage and see whats happening, could be another timer relay feeds this ??? Looks like its a 12v unit also. Some glow plugs are 4v some are 7v . Yours are maybe 12v .

 

[Mintyfresh77]

View attachment 121419


Very expensive these for some reason . Might be worth a trip to a garage and see whats happening, could be another timer relay feeds this ??? Looks like its a 12v unit also. Some glow plugs are 4v some are 7v . Yours are maybe 12v .

Yeah it's the price of the part in all my usual sources that concerned me and the sparse stock too. The plugs that came out were 7v and the NGK's supplied by MB the other day are the exact same. The plot thickens.....FML!

 

[OneForTheRoad]

Yeah it's the price of the part in all my usual sources that concerned me and the sparse stock too. The plugs that came out were 7v and the NGK's supplied by MB the other day are the exact same. The plot thickens.....FML!

Put ur reg into autodoc . Its pretty good at listing what glow plugs it should have in.

 

[Mintyfresh77]

Put ur reg into autodoc . Its pretty good at listing what glow plugs it should have in.

That's my usual go to place bud, just paranoid on pulling the trigger on these ludicrously priced modules without eye balling the old unit for compatibility which from what I've read requires car up, under trays off and it's somewhere up under the inlet manifold is where it dwells. Oh joy

 

[Mintyfresh77]

Just reporting back on this for anybody interested. Autodoc customer support took my VIN to cross reference the part and quickly sent me an aftermarket replacement glow plug module made by meat & doria (bizarre brand name but reputable manufacturer). I fitted the new module which laying on a garage floor and reaching up wasn't fun but I managed to fudge a number of 1/4 socket extension bars together to give me the reach and then used my combi drill to undo the 2 bolts holding the unit in place. Just reverse of that to refit but being a contortionist would help!!

Problem solved just in time for the below zero weather we've just had. Glow plug light comes on for 2 seconds, turn key and instant splutter free start even at -5degs. Happy bunny.

Thanks again for your input guys

 

[OneForTheRoad]

Just reporting back on this for anybody interested. Autodoc customer support took my VIN to cross reference the part and quickly sent me an aftermarket replacement glow plug module made by meat & doria (bizarre brand name but reputable manufacturer). I fitted the new module which laying on a garage floor and reaching up wasn't fun but I managed to fudge a number of 1/4 socket extension bars together to give me the reach and then used my combi drill to undo the 2 bolts holding the unit in place. Just reverse of that to refit but being a contortionist would help!!

Problem solved just in time for the below zero weather we've just had. Glow plug light comes on for 2 seconds, turn key and instant splutter free start even at -5degs. Happy bunny.

Thanks again for your input guys

Awesome , pleased 4u buddy.