W219 CLS 3.2 CDI starting issues...

[Phillyjim]

Morning all,

I have a 2006 CLS CDI. For some time now, It's been a little temperamental when starting from cold. It does however, restart fine once warm.

This is my first Merc so I'm a unsure whether this is simply a case of a fairly mature car not linking being woken up in the AM or if it suggests a bigger problem.

Your knowledge and expertise would be greatly appreciated.

 

[selphy]

Very likely to be one or more glowplugs have gone open circuit. Not difficult to change but they have a nasty habit of seizing in place so you may wish to take the car to a mercedes dealer or independent garage with suitable diagnostic equipment which will normally be able to say which glowplug(s) are faultly.

 

[Phillyjim]

Brilliant, many thanks Selphy.

 

[vijilants]

Does your glow plug light remain on for a short while after you started the car ?

Also is the engine management light on ?

If it is the OM642 engine, you will find that a faulty glow plug/s will show up with the glow plug remaining on for a short period after starting from cold and also the EML possibly remaining lit.

Note also on the OM642 engine there are two types of glow plug controller units as the latter type of unit is a modified unit due to problems with the older unit.

 

[KeithJG]

Check the error codes as it will say which glowplug ,if it`s that , is faulty.

Mine is 2006 and still with the older type relay, my indy said don`t replace if ok so i do believe it is a case of poor later parts!

 

[vijilants]

Usually one plug going faulty does not cause starting issues, but if it is diagnosed as glow plug/s and you are going to replace them and pay someone to do it, replace all six, as the rest will fail in time and you will save yourself a load of labour charges and hassle by doing all six in one go.

If you want to purchase the original mercedes plugs, try this link or speak to them:

Genuine Mercedes-Benz OM642 V6 Diesel Glow Plugs (Set of 6) A0011597101 NEW | eBay

It is Mercedes Benz Newcastle and they appear to be far cheaper than any other dearlerships on certain components.

 

[whitenemesis]

A modern CDI engine should start effortlessly even without glow plug assistance, unless the ambient temp is well below zero C. They are employed mainly for emissions reduction as the engine warms up.

Best get the codes read.