Glow Plugs???

[Eazyd123]

Hi All,

I have a CLA 200d (OM651) shooting brake AMG line 2015 (65).
Over the last 2 months it has been getting harder to start, especially as it’s getting colder in the UK.
I have noticed that the engine sounds off when driving a slight fluctuation sound like it’s slightly misfiring. There aren’t any lights illuminating on the dash (no glow plug sign or EML).
I was wondering if it’s glow plugs or something else.
The power seems okay but the engine just sounds off.

Any advice?

Thanks

 

[m80]

Unlikely that the glow plugs are bad as that should cause the light to stay on after it's started.
But if the controller is faulty maybe not.
W/o some diagnostics you / I are just guessing though.

 

[Eazyd123]

Thanks. Just a quick question does the glow plug light illuminate for a short period when turning the key to the first position (before turning the car over)?
My car does not show any glow plug light until I am literally turning the key to start the car then all lights show for a split second.

Thanks in advance.

(Mercedes CLA 200d shooting brake 2015 AMG line)

 

[W1ghty]

Thanks. Just a quick question does the glow plug light illuminate for a short period when turning the key to the first position (before turning the car over)?
My car does not show any glow plug light until I am literally turning the key to start the car then all lights show for a split second.

Thanks in advance.

(Mercedes CLA 200d shooting brake 2015 AMG line)

Yes it should illuminate before you crank the engine , because with a diesel you wait until it illuminates then goes out before cranking

 

[W1ghty]

Hi All,

I have a CLA 200d (OM651) shooting brake AMG line 2015 (65).
Over the last 2 months it has been getting harder to start, especially as it’s getting colder in the UK.
I have noticed that the engine sounds off when driving a slight fluctuation sound like it’s slightly misfiring. There aren’t any lights illuminating on the dash (no glow plug sign or EML).
I was wondering if it’s glow plugs or something else.
The power seems okay but the engine just sounds off.

Any advice?

Thanks

What mileage is the car on ? Because of the mention of misfiring

 

[Eazyd123]

It’s got 92k mate

 

[Eazyd123]

Yes it should illuminate before you crank the engine , because with a diesel you wait until it illuminates then goes out before cranking

As I thought but it doesn’t the only lights that display are the brake light (when handbrake is on obviously) the green light as I have auto lights left on and an airbag light.
The other lights only display as I turn the key to crank and they all flicker on for literally 1 second

 

[mercmancdi]

Even if heating plugs are bad once drove to temperature rises it should not misfire and run as should . You named misfire but don’t say if it leaves it after a drive.

 

[Eazyd123]

I think the term misfire may be misconstrued. It’s hard to describe in words but when accelerating it doesn’t sound smooth it has a fluctuating sound. It sounds as if when you start a car and the revs fluctuate slightly at cold but when accelerating.

I will try and records it…

 

[Eazyd123]

Even if heating plugs are bad once drove to temperature rises it should not misfire and run as should . You named misfire but don’t say if it leaves it after a drive.

No continuous!

 

[W1ghty]

It’s got 92k mate

I was wondering if the misfire/fluctuations bit at 92k mileage might point towards cam chain stretch/wear , especially with stop start ?
MB specialist time ?

 

[mercmancdi]

No continuous!

If continuous mis fire 99% rule out glow plugs.

 

[m80]

As I thought but it doesn’t the only lights that display are the brake light (when handbrake is on obviously) the green light as I have auto lights left on and an airbag light.
The other lights only display as I turn the key to crank and they all flicker on for literally 1 second

Will the majority of the lights remain on if you turn the key to pos' 2, but don't crank?

If not I would suggest that 'whatever' issue is preventing that needs to be resolved as a 1st step.
Likely as not that could be the cause anyway.

 

[Eazyd123]

I was wondering if the misfire/fluctuations bit at 92k mileage might point towards cam chain stretch/wear , especially with stop start ?
MB specialist time ?

I was hoping that wasn’t the case. It doesn’t make the chain slap/clatter sound at start etc.
I was contemplating changing the tensioner as this is the simplest and cheapest option.

Will the majority of the lights remain on if you turn the key to pos' 2, but don't crank?

If not I would suggest that 'whatever' issue is preventing that needs to be resolved as a 1st step.
Likely as not that could be the cause anyway.

Sorry, I realised that when I turn to position 2 the lights do come on including the coil light for a couple of seconds.