M274 engine overheating issue at speed

[tony gee]

I've posted this issue before but after some interweb searching ive come across info about this engine over heating at motorway speeds with the heater or AC on but no problem if its turned off, at low speeds with heater on no problem, some say its the thermostat that causes it but ive seen proof that its the water pump that causes it, the vacuum plastic arm under the pump seizes up and then this issue starts. ive got a new pump and just ordered the coolant, by the way a Mercedes dealer im getting the genuine coolant from said that MB only make one type now for all cars (the red stuff) !!!!
the next thing is to fit it and not a simple job

the coolant

 

[Bigdrew]

I've posted this issue before but after some interweb searching ive come across info about this engine over heating at motorway speeds with the heater or AC on but no problem if its turned off, at low speeds with heater on no problem, some say its the thermostat that causes it but ive seen proof that its the water pump that causes it, the vacuum plastic arm under the pump seizes up and then this issue starts. ive got a new pump and just ordered the coolant, by the way a Mercedes dealer im getting the genuine coolant from said that MB only make one type now for all cars (the red stuff) !!!!
the next thing is to fit it and not a simple job

the coolant

Hi tony does yours use the blue coolant

 

[tony gee]

Hi tony does yours use the blue coolant

ive had a look in the expansion tank and it looks like a dirty faded yellow !!!!!!!!!!! I bet its never been changed ?

 

[Bigdrew]

ive had a look in the expansion tank and it looks like a dirty faded yellow !!!!!!!!!!! I bet its never been changed ?

Probably not on one of my oder cars the coolant was blue as it was older than a 2014 madel I think after that it was changed to pink - violet

 

[tony gee]

Probably not on one of my oder cars the coolant was blue as it was older than a 2014 madel I think after that it was changed to pink - violet

I had it in my head that mine had the blue stuff, but theirs a lot of crap in my head !!!!