Hello Mbworld I just bought 2005 e55 about a month ago and now "coolant visit workshop" has popped up for a week now. Before I take it in to a shop just wanted to get some idea of what it might be.
First thing when the message pops up the temp gauge flutters up and down from 90 up to about 110 I believe. It goes up high especially if I'm in stop and go traffic . If I'm on freeway message pops up once but the temp will not go high just only in city. Any ideas? And now since 2 days ago it says check coolant but coolant Reservoir is full.
I don't think normal for temp to go up and every few seconds jumping 10 degrees high then down.

Second can it be bad intercooler pump that bring up visit workshop message? Thanks in advance.

 

Iat is normal your coolant level sensor can be unplugged check that first if it's fine then your sensor will need to be changed

 

never seen a code come up for the intercooler pump failing.....just leads to high IATs.

If you are running the factory original, I'd consider swapping that out for the upgraded Bosch 010 model.

 

Probable sticking thermostat, possible bad temp sensor, possible radiator fan not activating properly. Water pump is a distant possibility.

 

i still need to change my IC pump but that has nothing to do with the coolant temperature, as was stated will just result in intake air temperatures getting too high and the supercharger shutting off the next time you give it some gas after a prolonged pull

 

could be an air pocket, partial blockage or as Birdwell mentioned above your waterpump -- you could try to remove your thermostat and run it for a while flush your coolant system,, probably due for service anyway

 

I had that msg 1 year ago and just need to add some coolant. Nothing wrong. Coolant just evaporate with time.

 

I ran into this and tracked it down to a faulty coolant level sensor. The sensor is built into the overflow tank, so I replaced the tank. Problem fixed.