E270 Cdi Glow plug light

[james2747]

In this cold weather, after switching ignition on, I always wait till glow plug warning light goes out before cranking engine.
The engine always starts without any problem.
Question. 1.
Does the glow plug start cooling down again as soon as glow plug light in dash goes off?

The glow plug light often comes on again after engine has started and can remain on for a minute or so while I'm driving.
Question 2.
Is this normal or do I have a problem somewhere ... as I said before, engine always starts without any problem.

Any comments or advice much appreciated.

 

[mersum1es]

1. No. Plug is used a warm up phase and other situations emission purposes too. There is no indication light for those functions.

2. Light after start tells you have faulty plug/control. (can be still working but resistance in not anymore in range, thus function slightly different/fully off)

There should be fault code triggered.

 

[Tony Dyson]

An excerpt from the OM 651 System Description below

i Note
If a fault occurs in the preglow system, glow plugs
or lines, this is indicated by the preglow indicator
lamp and the fault is also stored in the fault
memory of the CDI control unit.

There are in fact 8 pre and post start glow functions in an OM 651, I wasn't sure if any post glow functions were indicated in the dash cluster but as the post above, it appears they are not! this would suggest you need your fault codes read !

 

[mattkh]

An excerpt from the OM 651 System Description below
There are in fact 8 pre and post start glow functions in an OM 651, I wasn't sure if any post glow functions were indicated in the dash cluster but as the post above, it appears they are not! this would suggest you need your fault codes read !

2 Qs
How did you find out that the OPs car has the OM 651 engine ?
How do I get access to the System Description of various Mercedes engines.?

 

[Tony Dyson]

2 Qs
How did you find out that the OPs car has the OM 651 engine ?
How do I get access to the System Description of various Mercedes engines.?

2 A's
OP's won't be a 651 it's too early but design features are often common features through a series
I'm afraid I don't know the source, the OM 651 description was posted on this forum by another member some time ago and I don't recall which member it was, I kept a copy as it was specific to my engine.

 

[V6Matty]

OP has an early OM647, the light coming in before start is normal and then returning for around 1 minute after start is indicative of a failed plug, as they are relatively easy to access in this engine for about £60 you can change all 5, get directly from Mercedes too as there are two different plugs available for this engine iirc.

 

[John Laidlaw]

^ this, it will probably go on for quite some time before deteriorating badly but worth doing IMO. Just read up on tips for removing glow plugs if you intend doing it yourself. Dead cheap if you shop around.... Just double check these are compatible with your 2003

5x Bosch Glow Plugs for MERCEDES W211 2.7 E270 CDI OM647 177bhp | eBay

Find many great new & used options and get the best deals for 5x Bosch Glow Plugs for MERCEDES W211 2.7 E270 CDI OM647 177bhp at the best online prices at eBay! Free delivery for many products!

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[V6Matty]

^ this, it will probably go on for quite some time before deteriorating badly but worth doing IMO. Just read up on tips for removing glow plugs if you intend doing it yourself. Dead cheap if you shop around.... Just double check these are compatible with your 2003

5x Bosch Glow Plugs for MERCEDES W211 2.7 E270 CDI OM647 177bhp | eBay

Find many great new & used options and get the best deals for 5x Bosch Glow Plugs for MERCEDES W211 2.7 E270 CDI OM647 177bhp at the best online prices at eBay! Free delivery for many products!

www.ebay.co.uk

I think they are the wrong ones John, beru are the ones I used on mine and as I mentioned had an odd voltage rating with was slightly different to the Bosch plugs, Beru were the oem at that time hence me suggesting go with direct from Mercedes.

 

[John Laidlaw]

I think they are the wrong ones John, beru are the ones I used on mine and as I mentioned had an odd voltage rating with was slightly different to the Bosch plugs, Beru were the oem at that time hence me suggesting go with direct from Mercedes.

Cheers Matt...did wonder- yes wise to call MB Grangemouth then.....

 

[james2747]

OP has an early OM647, the light coming in before start is normal and then returning for around 1 minute after start is indicative of a failed plug, as they are relatively easy to access in this engine for about £60 you can change all 5, get directly from Mercedes too as there are two different plugs available for this engine iirc.

Thanks Matty
Yes, engine code is shown as a 647.961
I've read up on how to check plug resistance while still in situ so will check all 5 in near future.
Thanks for your reply, much appreciated.
regards
James