C250 TD, Rough on start in the morning

[ManJ]

Hi guys, as youve probably heard me complaining over the past few days, its because im trying to get all the little problems out of the W202...
When I started it this morning after the glow plug light went off it was a very rough idle and just seemed to have a hard turn over, after I drove it a little and was starting it at various times during the day it was fine, just seems to be the awakening in the morning...

Any ideas?

 

[KLP 92]

Could still be a faulty glow plug. Also check for air in the diesel system, may be leaking in overnight from somewhere.

Next time before you start the car check the diesel pipes for air.

 

[ManJ]

Well the glow plug light does stay on after I start it for a minute or so, which obviously means a faulty plug, but have had merx in the past that had a faulty one, but they never started rough... Only this one

How can i check the diesel pipes for air?

 

[KLP 92]

Well the glow plug light does stay on after I start it for a minute or so, which obviously means a faulty plug, but have had merx in the past that had a faulty one, but they never started rough... Only this one

How can i check the diesel pipes for air?

The C250 does start really rough if there is a glow plug fault. I would chnage them first before investigating further.

 

[ManJ]

Any tips on changing them, or is it best to leave it to the garage, I have had a broken one before in the head, but Ive heard there is special precautions I can take and stuff to put on them to help them slide out better?

ManJ

 

[KLP 92]

Any tips on changing them, or is it best to leave it to the garage, I have had a broken one before in the head, but Ive heard there is special precautions I can take and stuff to put on them to help them slide out better?

ManJ

Make sure the engine is HOT. Take it for a hard run to help heat it up.

Don't use excessive amounts of force to undo them, as this can result in them shearing in the middle.

Its about a 1.5 hour job, not hard, just fiddly. Make sure you have a flexible extension as number 5 is awkward to get to.

 

[ManJ]

right, sounds good, isnt there something that i should use to soak them with first?

 

[GazCaff]

Use a T-bar to remove them, it's a 45 minute job at the most but remember to buy new seals for the inlet manifold when you change the plugs.

And yes, C250s do run like a bag of spanners when a glow plug is defective, I think its because they also have an "after glow" for the first few minutes of running.

 

[tim.100]

Use a T-bar to remove them, it's a 45 minute job at the most but remember to buy new seals for the inlet manifold when you change the plugs.

And yes, C250s do run like a bag of spanners when a glow plug is defective, I think its because they also have an "after glow" for the first few minutes of running.

Thanks for the advice on the seals. My 250TD had a bad plug and I just had them all changed yesterday. Costs were:

£115 inc VAT for 5 glow plugs and 10 seals. MB parts.

£117 inc VAT Labour - 2 hours.

Regards

Tim