W126- No hot air from the heater

[matsmith]

I am not getting hot air from the heater. It is luke warm even on max setting. Previously it was hot or cold, the seemed to be no adjustment from the controls. Now it's just cold/very luke warm!

I had recently noticed a noise coming from around the heater controls/radio which sounded like a cassette being chewed when the radio is off. Could this have some thing to do with it? It's a random, light squeaking noise.

Any ideas gratefully appreciated?

 

[guydewdney]

try a search for monovalve or duovalve - also check coolant level is correct...

 

[matsmith]

Thanks for the tips.

The car was about half a litre down on coolant. So I topped it up. I then ran the car and got it up to temp. I played around rocking the the heater controllers up and down and did manage to get it to give out hot air, the level of adjustment is limited but I can live with it.

I am concerned where that coolant has gone. There is no evidence of water in the oil or vice versa. Its not appearing to leak any but some water was dripping from the over flow pipe on the back of the radiator while the engine as running, but I think thats because I may have over filled it a little. I keep thinking I am getting whiffs of collant in the coming through the heater vents! Does than mean my matrix is kanckered??

 

[mike65]

Oh dear...check beneath the carpets in the front footwells. The fact its summer (ha!) might be helping mask the problem but usually you get a moisture biuld up on the windscreen.

some reading - http://forums.mercedesclub.org.uk/viewtopic.php?t=4439&highlight=matrix

Mike.

 

[matsmith]

No sign of a water leak in the foot wells but I did have a little bit of condensation on the passenger side of windscreen but it did clear as it heater up.

Has any one tried chucking in some rad weld and seeing if that can fix a leaking matrix??

I certainly don't fancy replacing it!!

Will it only leak when the heating is on? Ie if I jsut shut it down I can carry on using th ecar without rsiking it leaking or steaming into the cabin?