w202 water leaking inside pass area, coolant level down...

[ladd220]

Hi folks,

Hope u can help...

The car: 1998 w202 c180 Esprit, 180k miles.

The problem: I have a water leak... Having to fill the coolant reservoir every week... I have checked for cross contamination of water and oil, but both are clean, ie no water in the oils, and no oil in the water reservoir... No leaks under the engine bay area

Today, I saw for the second time that the front passenger side floor was drenched with water. I pulled up the mats and they were dripping. I checked to see if any of the drains were blocked, but they're fine and water runs through freely. I traced the leaking water up to the blower motor cover, but could not get any further. But there was water in that too... It seems obvious that there's a leak somewhere. But don't know how to trace it further.

Another problem I've had - not sure if its related - it that I am only getting hot air blowing out... The car has ac but doesn't make a difference whether its on or off...

Please help...

 

[DRBC43AMG]

A collant leak in the heater box perhaps?

 

[Dec]

As a temporary measure, you could get two hose clamps and clamp the long hose going into the duo valves and clamp the short hose that comes from the heater, through the bullhead, into the back of the engine.
See… sykes-pickavant Hose Clamps - review, compare prices, buy online
This will isolate the heater, you would also need to remove the electrical connection that’s plugged into the duo valves.

Dec

 

[ladd220]

Thanks for the replies. My suspicion is that its probably a coolant pipe that might be leaking. However, are there anything such as an evaporator or condenser related to the ac up there (above the blower) which might have failed causing the leak?

Also, could this leak have something to do with the heater only blowing out hot air?

 

[KillerHERTZ]

Do a search on the forum, there are countless threads on this. Mine was caused by leaves caught in the drainages holes causing it to overflow into the cabin.

 

[DSM10000]

Do a search on the forum, there are countless threads on this. Mine was caused by leaves caught in the drainages holes causing it to overflow into the cabin.

The OP stated that he only has hot air coming through as well as the water ingress, why would blockage by leaves cause this?

 

[KillerHERTZ]

The OP stated that he only has hot air coming through as well as the water ingress, why would blockage by leaves cause this?

I was refering to the water leak. however after mine leaked my heated only blew hotair until I changed the control unit (£30 off eBay)

Are you able to offer any other explaination?

 

[DSM10000]

I was refering to the water leak. however after mine leaked my heated only blew hotair until I changed the control unit (£30 off eBay)

Are you able to offer any other explaination?

Well you are saying that you had 2 unrelated problems so I am assuming blockage by leaves was not the reason for requiring a new control unit?

I was just trying to understand and work out if the OP had one or two issues here?

 

[KillerHERTZ]

Well you are saying that you had 2 unrelated problems so I am assuming blockage by leaves was not the reason for requiring a new control unit?

I was just trying to understand and work out if the OP had one or two issues here?

Not unrelated as far as mine was concerned, after my leak my heater started having problems.

 

[DSM10000]

But the OP has a low collant level that needs topping up so a leak rather than a blocked drain above is the likely cause for at least one of his problems?

Does the heater control unit short out when submerged?

 

[ladd220]

Thanks, everyone for the input.

Just to clarify, I have already checked the drainage and the water flowed through easily. Which is why I dismissed the blockage idea.

The reason I believe, it might be a leak is because the coolant level is always falling yet there are no visible puddles under the car or traces of water anywhere in the engine bay...

I haven't had time to get under or behind the glove box to investigate further...

The other problem I have is that the heater only blows hot air. This is why i asked about the air con components, because I wasn't sure if any of them use water from the coolant system, or whether its the refrigerent gas... This is why i enquired about the possibility of the two problems being related.

I have read a number of other post but they seem to be related to drain blockages or blown head gaskets...

Fortunately, I don't have either. But need to locate what and where the leak is coming from....

 

[Dec]

Try, as suggested, clamping the coolant hoses to cut off the coolant supply to the cabin heater, at least this should stop the flooding in the cabin and may help to confirm that the leak is indeed inside the cabin.

See… https://mercedessource.com/node/8847

See also, our man in Taiwan… Evaporator replacement core Mercedes-Benz W202 C240

How much coolant would you lose if you were to take a 30 mile drive?
How much were you topping up by in a week?

Dec

 

[ladd220]

Thanks for the suggestions so far. Going try and get to the root of the problem this weekend and will let you know what I find... Thanks.

 

[bes1110]

If the water in the cabin was from the heater matrix it usually would have an obvious coolant smell in the car and the windows sometimes steam up. I would clamp of the heater hose's or bypass the heater unit by connecting the two hose's together.