Leaking coolant inside the car

[Kirsty candler]

Hello.
I have a ml270 2001. I have notice the last couple of weeks the carpet drivers side and rear drivers side has been wet. It seems to be coming from the heating/aircon vents. I have taken off the dash to see if there is any pipes broken/split. Which there is none.
It is coolant as it is staining the carpet and mats and also not drying.
Anyone else have this problem and been able to fix it.
Any help would be appreciated.

 

[LostKiwi]

Possibly a leaking heater matrix.
Probably a swine to remove too....

 

[Blobcat]

As per above or blocked scuttle drains and the rain water running down the screen then comes through the heater matrix into the footwell.

Are you losing coolant and having to top it up?

 

[Kirsty candler]

As per above or blocked scuttle drains and the rain water running down the screen then comes through the heater matrix into the footwell.

Are you losing coolant and having to top it up?

Yes losing coolant. Checked all drainage bungs and not blocked.

 

[Kirsty candler]

Possibly a leaking heater matrix.
Probably a swine to remove too....

How can I get to the heating matrix as taken a lot of the dash off. Just don't really want to take the rest off unless really have to.

 

[LostKiwi]

Never done one but it will probably reguire the dash out.

 

[grahamcol]

A pig of a job this is / will be l feel. Just as an alternative you might consider a sealant such as a modern equivalent of Radweld. I forget the name of the product l used four or five years ago on an old car. I must stress that l wouldn't normally advocate the use of such a product in a "good" car but in something which has relatively little value it might be worth considering. I think success rates vary and beware there's a chance you could cause a cooling system blockage if you're unlucky. Your decision.

 

[LostKiwi]

A pig of a job this is / will be l feel. Just as an alternative you might consider a sealant such as a modern equivalent of Radweld. I forget the name of the product l used four or five years ago on an old car. I must stress that l wouldn't normally advocate the use of such a product in a "good" car but in something which has relatively little value it might be worth considering. I think success rates vary and beware there's a chance you could cause a cooling system blockage if you're unlucky. Your decision.

Steel Seal or K-seal are the usual suspects.
They may stop the leak but may equally block the heater matrix.

 

[Blobcat]

but may equally block the heater matrix.

Which would stop the leak...

 

[grahamcol]

Yes, K Seal is what l used but frankly l don't rate it very highly. My intention was to merely inform the op of another option, albeit one which can have its drawbacks.

 

[star]

You can smell a heater matrix leak, hot antifreeze. Here’s a 212 e class matrix job.

 

[Kirsty candler]

There is no smell. The water is coming from the air duct, drives side and rear drivers passager. Have included a picture.

 

[LostKiwi]

There is a heater box drain pipe that drains any water in the heater box I wonder if that's blocked?
Look for a tube about 1/2" in diameter and try disconnecting it and blowing through it.
Thread here with a diagram.
https://forums.mercedesclub.org.uk/index.php?threads/air-con-drain-w163-ml270-2003.85981/

 

[mioba]

The OP has said it’s coolant and the coolant level drops.

How is that related to condensate from the AC.

 

[LostKiwi]

The OP has said it’s coolant and the coolant level drops.

How is that related to condensate from the AC.

Post above mine. "There is no smell".....
Coolant has an odour to it. It's possible coolant is being lost elsewhere and this is a secondary issue discovered by looking for a leak.

 

[joderest]

I have had wet carpets in that location twice, first time was air con drain blocked, second time was rubber bungs under wing leaking ( think they are for sunroof drains when sunroof fitted, which mine does not have).
Drains exit above gearbox, I did find them and clear, lots of sealant round the bungs cured that one, you can only feel them, not see them unless you take wing off.

 

[Kirsty candler]

Ac drain is not blocked and bungs are not blocked. It is definitely coolant as I'm having the level light come on every couple of days..
It is coming out of the heating ducts.

 

[Craiglxviii]

You’d smell the glycol in the cockpit. Do you find your eyes watering while driving?

 

[LostKiwi]

Ac drain is not blocked and bungs are not blocked. It is definitely coolant as I'm having the level light come on every couple of days..
It is coming out of the heating ducts.

In that case you'll need to try a sealant (which I personally hate) or pull the dashboard out to get to the matrix.

 

[Kirsty candler]

No eyes burning. The water leaking is not 100 % coolant as been topping up with water