Passenger side headlight keeps dropping

[eblok]

Hi all,

This is my first post on here so please be gentle...

I drive a 2007 W209 CLK Sport and now the nights are closing in it seems a good time to get my headlight problem sorted.

Basically for the last 6 or 9 months (cant remember exactly but its a long time) whenever I've been driving along behind another vehicle I convinced myself that my passenger headlight was pointing way too low. Taking it in for a service and MOT a few weeks ago they confirmed this and 'adjusted it up' so it passed the MOT. This was at an MB dealer I might add.

Within a few days when driving to work I noticed that things are back how they were before. I guess they have adjusted it with the screw on the top enough to pass the MOT without solving any underlying problem. This is why I'm keen to get your opinions rather than them charging me to 'investigate' any issue.

When I use the beam height adjuster on the dashboard only the drivers side light moves up and down, and when it is at its lowest (for if I have a fully laden car) it seems about the same as the passenger side. Are these adjustments done electronically or using a vacuum? If its a vacuum hose I'm wondering if there might be a leak on the line to that light which is causing the passenger light to drop and also not adjust. Looking in behind the headlight I can't see a great deal in terms of adjustment but thats mostly because access is terrible. If there is a vacuum line can anyone point out where it might be?

As an aside, my seat adjustment (lumbar, etc) which is vacuum controlled too I think is also playing up. It is intermittent which sort of suggests a leak somewhere. Could these issues be related?

Any advice would be greatly appreciated.

Thanks and best regards,
eblok

 

[Dieselman]

The seat adjustment is electric and these cars do suffer with loom chafing.

The headlamp adjustment is vacuum controlled. Check the purple pipe leading to the headlamp.

 

[Major774]

Has that headlight been replace for a manual headlight... without the electric motor adjustment?

 

[eblok]

Dieselman, thanks for the info, I'll check the purple pipe tonight. Once I know what I'm looking for it becomes a lot easier! As for the seats, I'm sure they aren't electric as if the seat is inflated I can hear the air venting out when I deflate. There seems to be 2 air bags in the back of the seat, one in the base and two either side.

Major774, I've been led to believe (from other searches on this site) that some of the headlights were electrically controlled and some were vacuum. I'm not sure if it comes down to Xenon vs Halogen or what. My lights are standard halogen.

Thanks

 

[Dieselman]

Apologies, the lumbar is air operated.

 

[andy27168]

Hi,
You should have a purple plastic pipe feeding the headlight for the levelling, this pipe runs from the fuse panel area down the inner wing to the headlight then is looped off and runs in front of the radiator to the other headlight, I reckon its this link that has become damaged or disconnected.
The seats are fed from the PSE pump in the boot via an accumalater, check ALL the operations of the air operated seats immediatly after starting, If any of them work initially than faill after 20 seconds or so then you have an air leak.
This COULD be down to the headlights but unsure as I thought these were vacuum operated rather than operated by air pressure.
The seats can leak, normally at the connection at the base of either seat or take the seat back off (two screws on the bottom edge of the seat back) and check the pipes there as the side bolsters can become disconnected through the seat/seat springs flexing to much as they become older.

 

[eblok]

Thanks for all the information Andy. I'll start chasing the pipes around this weekend and make sure to check operation immediately after starting the car this evening.