[chidbax]

Hello
I am having problems with w212 E250 CDI, with 651 engine

After 10 mins of driving the top up coolant light will come on
When I checked I found the radiator hoses bulged, a sign of excessive pressure

I replaced radiator pressure cap to no avail
Does any have an idea of what my problem might be

 

[peterjmdr]

There are test kits available that will identify the presence of combustion hydrocarbons in the coolant liquid. Fairly simple test. If hydrocarbons are present in the coolant fluid it is coming from a defective head gasket which is allowing exhaust gases to enter the coolant system in the block. This in turn will build pressure in your coolant system as the engine runs. You might also check the coolant reservoir for bubbling which is another indicator of the same issue.
Here is the Amazon link for that test kit:
https://www.amazon.com/Block-Tester...t=&hvlocphy=9010938&hvtargid=pla-570352767565

 

[tony1963tony]

Sounds like a blown head gasket to me.

 

[plinker17722]

Pull the engine colant thermostat and replace it first ..Easy jiob and better than pulling the head off .If thermostat failed closed all water will escape through the overflow tank as water gets hot .

 

[peterjmdr]

Hello
I am having problems with w212 E250 CDI, with 651 engine

After 10 mins of driving the top up coolant light will come on
When I checked I found the radiator hoses bulged, a sign of excessive pressure

I replaced radiator pressure cap to no avail
Does any have an idea of what my problem might be

Have you made any progress on this issue?
Please let us know what additional information you have. Thanks.