Glow Plug problem

[KKG]

Hi all,

I've got a W210 E300TD with a glow plug problem which is intermittent.

When starting the car, I wait for the glow plug light to go out and then
start it.

However, the glow plug light re-appers for around 45 seconds.

This does not always happen; perhaps in around 20 starts, it may happens once.

The glow plugs and the relay has been changed.


Any ideas you clever ones ?

 

[smity]

mid life crisis can u help me please it smity

 

[Frank Patten]

My 2003 W210 E220cdi does this all the time. Is this a fault?

 

[LAMAR]

If the glow plug light stays on after starting this is usually an indication that one of the glow plugs is faulty and there will be a DTC stored in the engine control unit.
You can test the glow plugs with an OHM meter. connect on lead of the ohm meter to earth and disconnect the plug from the glow plug relay insert the other lead of the ohm meter into each of the connections for the glowplugs.
As the glow plugs go to earth if working correcty the you should have a circuit, if not then the glow plug is open circuit an d faulty

 

[KKG]

I did this yesterday and all seemed fine.

Could it be connection problem ?

 

[KKG]

Has anyone got any ideas ?

 

[Bolide]

Glow plugs

The W210 is similar to a W124 but with added electronics. So...

The light coming on after the engine starts is a fault indicator. If the plugs & relay have been swopped and the plugs test OK with an ohmmeter then I'd suspect the relay unit is oversensitive or a couple of plugs are marginal on resistance

The fact that it happens intermittently points to either an intermittent fault or an oversensitive unit. On the occasions that it happens, does the engine run rough as though one glow plug hasn't been lit? You'll only notice this when starting from cold. If it's lumpy then maybe a plug is failing (unlikely) or a wire is broken (also unlikely) or the plug that attaches to the glowplug isn't seated properly or is broken & doesn't click home properly

You can test the plugs at the relay - this'll test the wiring & plug. Be aware it's difficult to get an accurate measurement of a low resistance. Are they MB plugs or pattern ones?

This'll be a hassle when you come to sell it

Whoever replaced the plugs & relay didn't finish the job, did they?


Nick Froome
www.w124.co.uk

 

[KKG]

Thanks for the tips.

It usually happens when the engine has warmed up i.e. starting from cold,
it is fine.

The plugs are by bosch; so I guess they should be ok.

When you mean some resistance, how many ohms are we talking about ?

 

[Bolide]

Resistance (is useless)

I don't know what the resistance should be or what the tolerance (± so many ohms) is either. A helpful MB parts person might do, or a genned-up auto electrician or diesel expert

I don't know if there's a relationship between the fault being more apparent and the car being warm. Possibly. The resistance of the plugs will change with temperature but I'd assume only minutely

You need an expert here. That engine's in the late W124s and early W210s and I believe versions of it are all over the place in Sprinters & the like so maybe try a commercial diesel specialist. You'll need to tell them exactly what's been changed and what's been tested

I don't know if I can be of any more on this one. But I suspect the relay unit


Nick Froome
www.w124.co.uk

 

[jakmeticklerpaper]

glowplug indicator

Best thing is to read your handbook but maybe this is too simple an answer? The glowplug light function is not even understood by MB service people it seems.
The light should come on when you switch on the "ignition", it should then go off when the plugs are warm. Then you start the engine and the light SHOULD come ON again, for a period of about 30 seconds (if cold) or less if the engine is warm.
I've had plenty of "experts" sucking their teeth and telling me "The glowplugs all need changing Sir, very big job, they're usually seized in, could possibly fit you in in a couple of weeks blah blah." It's all bulldung!
Does the engine (more or less) start first time, every time, winter and summer? Then there ain't nothing wrong with your glow plugs. If it ain't bust, don't fix it!
j

 

[LAMAR]

Best thing is to read your handbook but maybe this is too simple an answer? The glowplug light function is not even understood by MB service people it seems.
The light should come on when you switch on the "ignition", it should then go off when the plugs are warm. Then you start the engine and the light SHOULD come ON again, for a period of about 30 seconds (if cold) or less if the engine is warm.
I've had plenty of "experts" sucking their teeth and telling me "The glowplugs all need changing Sir, very big job, they're usually seized in, could possibly fit you in in a couple of weeks blah blah." It's all bulldung!
Does the engine (more or less) start first time, every time, winter and summer? Then there ain't nothing wrong with your glow plugs. If it ain't bust, don't fix it!
j

:!: :!: :!:
If the light comes on again after the engine has been started, this is a indication of a fault.

 

[Bolide]

:!: :!: :!:
If the light comes on again after the engine has been started, this is a indication of a fault.

Correct

As I recall the dash indicator goes out but the glowplugs stay on at a lower power level to make the engine get up to temperature more quickly

It's a tricky old thing, that glowplug relay


Nick Froome
www.w124.co.uk

 

[mickt]

Hi

just to prove I've read about the relay and glow plugs, Im posting this reply here.

been having a problem for sometime time, sometimes the heater light wouldn't come on, then it would, this is when I turn the ignition on to make it clear.

couple of days ago, got in the car, turned on the ignition, the heater light came on for 1 second, started to flicker and dimmed out with a buzzing sound coming from inside the engine bay I assume, the glow plugs have not worked since, this is a genuine fault and I believe the relay is fried, sniff sniff can you smell burnt feather's

Im looking for another relay for a W124 250D 5 cylinder