W164 ML headlamp washer broken in freezing conditions

[Bobby Dazzler]

This morning there was a fairly thick frost, and the car had been parked outside overnight. I pushed the headlamp wash button without thinking, when it didn't spray I gulped and hoped there was no damage.

This evening driving home I hit the button again to test if there was any damage and they sprayed, but stopped on the third push. Having tried again when I got home, the stalks are not popping out when the button is pushed.

When the button is pushed I can hear a motor running behind the nearside (passenger side) headlamp, but can't see any sign of water dripping squirting behind the bumper, but the weather was awful so I didn't try for long.

Any thoughts on what to check? If it's bumper-off or headlamp-out job then I may need to book it in to get someone else too look which could make this an expensive and unnecessary fix.

 

[Will]

Not familiar with the headlamp/washer design of the ML, but many of the ones I've seen use the pressure of the washer fluid itself to extend the washers and then spray. The motor you hear is the washer motor - not the bit that extends and squirts, they usually operate hydraulically from the fluid under pressure.

Is it possible a pipe/connection has come off? I know you didn't see any fluid but you might notice washer fluid dripping from behind/below the bumper area if so. You might need an assistant to investigate - if you can get them to pop out again you'll need to grab them before the flap retracts in, so I'd try again when the weather improves. I think they have a screw or two mounting them which you can see when they extend out.

Hopefully something simple like that. If they won't extend again then you might need to get behind the bumper to investigate? You might be able to carefully pull/lever the flaps forward but be careful to not mark them or the bumper of course.

FWIW, it will probably fail the MOT if not working, probably one of the smaller items people forget these days

Good luck,

Will

 

[kid-jensen]

Bumper off takes about an hour and really needs two people to save scratching anything.

No special tools required.....maybe wait till the weather improves and give it a go..

 

[Bobby Dazzler]

Thanks both. Not been at home in daylight hours since, but will investigate further.

Fortunately the MOT is some way off, but it's one of those things you could get into the habit of not using, so not fixing, and failing come MOT time.

Other thoughts welcomed.

 

[zenman63]

As Above they work on fluid pressure from the pump.
Might be just a clip, you can get a blunt plastic tool under one and pull up to see if its attached, wheel arch liner will give all you need, worst case bumper off, all easy enough when you work out the clamps on the wing to bumper joint.
Better still where is the button? I looked everywhere for one on mine and gave up, it only works on 3-4 screen washes.

 

[Bobby Dazzler]

As Above they work on fluid pressure from the pump.
Might be just a clip, you can get a blunt plastic tool under one and pull up to see if its attached, wheel arch liner will give all you need, worst case bumper off, all easy enough when you work out the clamps on the wing to bumper joint.
Better still where is the button? I looked everywhere for one on mine and gave up, it only works on 3-4 screen washes.

Thanks for posting.

Do you mean place a blunt plastic tool under the washer cover to pull it out?

The button is to the left of the headlamp switch on our car.

 

[zenman63]

Yes get a filler card, or a stiff tapered plastic tool and get under it, it will pull up.

Mine has no button, I spent some time looking for it then one day washing the screen bingo the head light wash worked.

 

[Bobby Dazzler]

Yes get a filler card, or a stiff tapered plastic tool and get under it, it will pull up.

Mine has no button, I spent some time looking for it then one day washing the screen bingo the head light wash worked.

Smashing, thank you for your help

 

[markmifsud]

Sounds more like the washer pump is low on pressure. If you had a leak in the pipes, you would see it as theres a hell of a lot of water sent through. If one of the stalks had a leak, again you would see it. If the stalk was just plain dead, then wouldn't the other side still be working?

If it was my car, and neither headlamp stalk was extending but the pump was running, I would be looking for whats common between them. To me, thats the actual pump?

Have you tried to take the water pipe off from the pump to test what sort of pressure its working at.

 

[Bobby Dazzler]

Sounds more like the washer pump is low on pressure. If you had a leak in the pipes, you would see it as theres a hell of a lot of water sent through. If one of the stalks had a leak, again you would see it. If the stalk was just plain dead, then wouldn't the other side still be working?

If it was my car, and neither headlamp stalk was extending but the pump was running, I would be looking for whats common between them. To me, thats the actual pump?

Have you tried to take the water pipe off from the pump to test what sort of pressure its working at.

Not had chance yet, but I'll see if I can find the pump. Thanks

 

[Bobby Dazzler]

Update: it seems the headlamp washers are disabled when low on washer fluid.

I used the car today, and when I used the windscreen wash I also tried the headlamp washers, in case fairies had fixed them whilst I slept. They hadn't. However a warning appeared on the dashboard: low washer fluid. It got me wondering whether it might be linked.

When I got home I tried the headlamp washers again, and still not working. I topped up the washer fluid, and tried again, and they seem to be working perfectly again! For now I have concluded that they're disabled when the fluid is low.

I'll try them more frequently in the coming weeks, in case this is a coincidence, and there's a temperamental fault.

Thank you once more for all of your help and suggestions