E320 overheating

[Scroober]

My e320 is overheating. I have had the water pump replaced and a new thermostat but to no avail, any suggestions?

 

[w124nut]

Is the radiator core free from debris/dead flies etc?

Is there enough water in the cooling system?

There maybe an airlock in the cooling system.

Does the heater/air conditioning work?

Mind you, the air temperature in my garden reached 40c earlier today so that won't help things.

 

[Scroober]

I keep filling the header tank and the water seems to disappear. I cannot see any leaks and there is no water in the oil.

 

[w124nut]

It must be going somewhere either as water or steam.

Is the water level in the header tank visibly dropping?

Have you had the bonnet up when the engine is hot and running and looked for any signs or smell of water/antifreeze escaping? (be careful when doing this)

 

[kth286]

have you let the car idle when stationary.

you need to drive over sheets of newspaper taped together to ensure under car coverage.

Let us know the results.

 

[Major774]

May be a slight leak with the head gasket?

 

[Braincrank]

I keep filling the header tank and the water seems to disappear. I cannot see any leaks and there is no water in the oil.

Had the same / similar issue and after checking every pipe and hose I now found that the heater return hose where it joins the motor block ( on my 124 it's at the rear right hand side of the cylinder head ) is corroded/porous and leaks when the engine is hot .

 

[Scroober]

I have checked out the heater return as suggested, it appears that this is the cause. How did you repair it?

 

[grober]

That's actually the supply line to the heater --- one in then 2 out. If its the metal pipe its other end will be on the heater itself inside the car. Not easy to get at.

 

[kth286]

is the floor under the carpets wet ?