[John H]

Hi guys,

My 180E seems to have made around 750cc of coolant somehow vanish in the last 1000km. I was checking fluids before doing a big trip over the weekend and noticed the overflow bottle level was right down.

I've looked at the top/bottom hose and the pipes leading to the heater (from the engine bay) and can't see any signs of leakage. I've also checked the dipstick and oil filler cap and there's no sign of "mayonnaise". There's no obvious sign of wet patches in the interior from a leaking heater core.

Any tips? Logical things to check next?

PS - I made this discovery just after all the places that stock the MB coolant or Valvoline Zerex G05 had conveniently closed for the weekend. I chose to top up with distilled water than risk putting the wrong coolant into the radiator. Bad mistake? Will I be OK if I just make a slightly stronger mix of coolant when I get some Zerex to offset the dilution from adding water only?

 

[1984babybenz]

You are fine just putting distilled water in. Some people run exclusively on it.

Try checking when the car gets up to its maximum running temp. Not sure what it is on the 180e, but on my 190d it's 100C.

Some pinhole leaks will appear when the water is hot.

 

[vishvamata]

Recommendation is at least 33% coolant, to prevent oxidation of iron block. Distilled water helps avoid mineral deposits.

 

[aardvark]

Mine has been leaking for 2 years now, and last year I found a little on the ground.I was able to finally (after extensive digging and time) find that the damned plastic sided radiator was seeping at the seam, close to the upper hose. I've just been driving it like that since.
The radiators are quite suspect and common to let go, but many times they let go at the hose neck. If that is the case and they leak there, it's an immediate replace since it could let go at any time.

 

[eric242340]

Take it to a local workshop and ask them to pressure test the cooling system, any external leak will show under this test, and if it does not leak out then it is leaking in, ie head gasket.

 

[aardvark]

And to follow up on that (Eric), hows your oil/coolant?
Any brown foam on the oil filler cap? Any slime in the coolant canister? Those are a few visible signs for head gasket leaks, but not the only ones.