ML duo / mono valve

[Andy Wr]

Noticed a problem this morning, my car warmed up the interior fine, I parked up for 3 hours in a cold frosty field whilst shooting and when I returned I could not get any heat out of the vents. The car water gauge temp was normal, just no heat output, I stopped the car, restarted it and the heat then worked fine and has been ok for the rest of the day.

I suspect the duo or mono valve is playing up from searching previous posts. Does the ML have a duo or mono and where exactly is it situated, is this prone to sticking and is it an item which can be stripped and cleaned. I have checked on the Russian site and can not find the item in question. Any help as always appreciated.

 

[television]

You are asking a hard one here

http://www.detali.ru/cat/oem_mb2.as...GM=716.644&CT=F&cat=06H&SID=83&SGR=045&SGN=01

I think it is 83, but it is avery complicated set up, If I were you I would wait and see what happens.

Malcolm

 

[Andy Wr]

Thanks Malcolm but number 83 is the thermostatic expansion valve for the air conditioning system, I recognise it from past experience, I just cant seem to find a duo valve, will have to have a look at the car and follow the pipes back from the heater matrix.

 

[Blobcat]

I notice on the Russian site that the ML Heating and ventilation page is missing section 180 - Heating Water Connection. That maybe correct or an omission I don't know. But that is the page that shows the duovalve.

Here is the page for the ML - http://www.detali.ru/cat/oem_mb1.as...963&GA=722.661&GM=716.644&CT=F&Cat=06H&SID=83
And here is the page for W210 E320 for comparison - http://www.detali.ru/cat/oem_mb1.asp?TP=1&F=210026&M=613.961&GA=722.626&CT=F&Cat=66G&SID=83

 

[television]

OK i will add it to my search list for tomorrow.

Malcolm

 

[eric242340]

ML Duo/mono valve

I have jhust had a look at a ML250 and an ML320 , both cars are younger than yours, however both have a Mono valve between the battery and the MAF. Two heater pipes connected - one in /one out. Also an electrical connector. The appear to be sealed units. Hope this helps

 

[panason1c]

I have jhust had a look at a ML250 and an ML320 , both cars are younger than yours, however both have a Mono valve between the battery and the MAF. Two heater pipes connected - one in /one out. Also an electrical connector. The appear to be sealed units. Hope this helps

That sounds like a description of the auxilary electric coolant recirculating pump.......

 

[Andy Wr]

That sounds like a description of the auxilary electric coolant recirculating pump.......

Yes it is, I have already found that, in theory it has got to be at least a mid postion modulating valve to divert the hot water or a proportion of it, it does look like a page is missing compared to the other models on the site.

 

[psmart]

On this link http://www.detali.ru/cat/oem_mb2.as...132X737584&CT=M&cat=21T&SID=20&SGR=015&SGN=01 (2nd picture down)

You have the main engine thermostat, item 44, which is the primary coolant thermostat and you have item 98 which is a low temperature thermostat. Could this be the chappie?

Cannot locate any other valve which works on the coolant system, unless the ML's have permanent hot coolant circulated into the Heater Box and the actual valve is internal to it.

 

[Glenn Smith]

On this link http://www.detali.ru/cat/oem_mb2.as...132X737584&CT=M&cat=21T&SID=20&SGR=015&SGN=01 (2nd picture down)

You have the main engine thermostat, item 44, which is the primary coolant thermostat and you have item 98 which is a low temperature thermostat. Could this be the chappie?

Cannot locate any other valve which works on the coolant system, unless the ML's have permanent hot coolant circulated into the Heater Box and the actual valve is internal to it.

Not common on a merc. but many sytems have no valve at all for the coolant, temperature is controlled by the fesh air flap (diverts more or less cool air over the matrix) I would be more suspicious of the heater coolant pump being faulty

 

[eric242340]

Ml

That sounds like a description of the auxilary electric coolant recirculating pump.......

Yes it is and its also for the heating, we commonly refer to it as the after running pump but it serves the heating too. I dont know of any problems with the pump on the ML but the S Class has a Duo valve and if it goes wrong - no heating and on the S class they are often going wrong.

 

[television]

Eric you have a PM

Malcolm