W124 experts any Help please - fried something

[pdr300D]

Hi all,

I am a proud new owner of an W124 300D (for about a month now). And its been used on a few trips of moderate distance so far without hitch.

Today on my way back from Winchester - I smelt a dreadful chlorine like smell - followed by a small stream of grey smoke emanating from around the central console buttons - actually right from around the airco and recycle buttons. I then saw smoke come from behind the rear window washer/wiper button. Smoke stopped - kind of - but smell continued..

Fortunately I was only 5 miles from home - so I switched off the blower and aircon and proceeded with care.

When I got home - I popped the bonnet - but didn't notice anything at first - all the visible fluid levels looked ok.

I then noticed a puddle had developed behind the front right wheel - with a fairly constant drip. Looking in the engine bay again I noticed a puddle of water underneath the brake master boost cylinder - and a wet area around some electrical component (looks like some sort of valve mechanism) - see photos. Dont know what this is but it was extremely hot - and had melted a plastic cable tie that was touching it.

I started the engine again - to see if I could locate the leak - and noticed smoke coming from the plugs on this thing..

So can anyone help diagnose whats wrong, what needs fixing - and whether I've fried my airco controls in the cabin? (The little ECO red light doesn't come on now )

Expensive?

Its booked into a Merc dealer for a oil service on friday - so I also need to know if its driveable..(to take it there).

Can I disconnect the plugs from the component I described above?

I've uploaded some photos - to help describe the problem

Thanks for any help

phil

 

[Frank O' Phile]

Looks like your duo-valves. They regulate the heating for left and right controls. Your coolant passes through these.

Should be okay to drive disconnected, but your heating will be stuck on hot (or cold) can't remember.

 

[moakesr]

Yep, looks like your Duo-Valves or circulation pump have failed, and regrettably they may have drawn too much current and damaged the heater control unit

Is yours the one with a set of push buttons in a horizontal line? Or the classic circular controls?

 

[DansSlk]

Certainly looks to be coming from the duo-valves, not a huge issue in itself unless the car loses lots of coolant of course.

I would want to inspect behind the panel's inside the car to double check on that smoke mind you especially if it was coming from around the button's because of the risk of control unit damage.

 

[Dieselman]

I'd agree with the above, one of the valves has leaked water in, shorted out and fried the heater control unit.

Almost certainly it's going to need new valves and controller.

 

[pdr300D]

Thank you all,
I'll take a look in the morning and post results...

 

[pdr300D]

I have horizontal buttons for rear wiper and hazard lights at the top of the console - immediately below the vents..
The aircon buttons are vertical - between the vertically scrolling dials that set temperature for left and right.

 

[imadoofus]

I have horizontal buttons for rear wiper and hazard lights at the top of the console - immediately below the vents..
The aircon buttons are vertical - between the vertically scrolling dials that set temperature for left and right.

So you have aircon, rather than climate control. Well that should make finding a replacement panel, if one is necessary, a lot easier.

PJ

 

[moakesr]

Lots of heater control panels going cheap here http://www.starpartz.co.uk/catalogue.asp?search=heater&submit=find+part

This guy on ebay had a load of duovalves listed recently, I bought one! http://myworld.ebay.co.uk/silverbill1936 I suspect he still has loads of them in stock, just not currently listed. Give him a shout, he is a really nice bloke.

Hopefully these links will help you fix this without breaking the bank

 

[pdr300D]

FYI - Here's some pics of the fried PCB for the heater control panel.

Out of interest - does anyone know if its worth getting the PCB repaired? Looks like fairly common components on the board..but I'm not an expert..

Main dealer had a look at the duo valve today - and its kaput - new one is +/- 300 quid incl VAT .
I believe they could be serviced having had a look at other projects people have undertaken. Though I may just bite the bullet on this one..and service the old one so its a spare..

Starpartz dont have the same controller on their website (have mailed them to see if they know where I can find one or if they have something not on the website). Theres also a couple of second hand ones on ebay.de - so may pursue those..if I can figure out how to pay them without using paypal as they only do bank transfers..what a pain.

Oh and thanks for the help so far - am new to this forum - and am finding it fascinating.

phil

 

[Bazzle]

Just be sure to keep an eye on your coolant level with that leak. As its high it could put an airpocket at head height.

Bazzle

 

[neilrr]

Ooops, forget it - just saw the original picture.

 

[neilrr]

I think I have the parts you need. If you'll send me an email addy I'll send you photos & you can see what's what.

 

[Dieselman]

That's just a standard output transistor, you could buy one at Maplin, CPC or RS components.

It would probably work after a new one is fitted.

There are lots of 124 being broken so a duo valve should be easy to get. It could even be rewound and resealed if really neccesary.

 

[pdr300D]

hmm I cant PM you - facility not available to me yet (I think). So here goes ..


Thanks for checking

 

[neilrr]

Thanks,

OTW.