W202 Losing Water and Heater problem

[Ekko Star]

Two problem that are bugging me, so all help would be appreciated please...

Firstly, I have noticed my water light comes on every few weeks. Need to top the radiator up with quite a bit of water when this happens. There are no obvious signs of water leakage around the radiator or from visible hoses in the engine bay.

Secondly, my heater constantly blows hot, on both driver and passenger side. From some of the other threads it seems the most likely problem could be the duovalve ? Is this the best place to look at first and is there anyway to remove this thing easily to see if it can be cleaned out by dismantling ?

I'm thinking both problems maybe related or maybe isolated. I'm no mechanic I must say but am just using my common sense and these excellent forums to try track down the likely problems

Things is I tend to run the heater all the time at the moment to demist the windows (no A/C on my car). I was thinking it maybe due to that ? The leakage maybe from the heater matrix (since I am using it all the time ?) or it could be something more fundamental like the water pump leaking ?

Any help would be great or what would be even better was if there were any enthusiasts/mechanics in the Bedfordshire area that were good with these sort of things ? Car is due for an oil change and service but would prefer a mechanic more used to Mercs.

Thanks

 

[Gollom]

Welcome to the forum! Lot's of knowledgeable people on here who will be sure to try and help.

But first thing they will need is some details on what car you have

Have fun!

Edit: Hangs head in shame having just noticed car type in subject line

 

[LastMinute]

See [THREAD=26888]this thread[/THREAD] for how to disassemble the duovalve. It's for a W210, but your W202 will be similar.

 

[Ekko Star]

Hi guys

It's a '94 C180 W202, its done 150K, but the car runs like an absolute dream straight out the showroom stuff and is pretty much in mint condition otherwise.

It's been my one and only Mercedes and TBH I will never buy another brand again if all Mercs are as good and ultra reliable as this thing. All I've ever done is have the oil changed and serviced every 6000 miles and the car just keeps on going and going.

Anyway back to the problems.....I've checked the oil cap and there's no clouding of the oil so it's not a 'serious' problem such as blown head gasket.

 

[BlackC55]

Water pump is quite likely. Have a close look at it when the car is running for any signs. The other problem is probably going to be a duo valve.