Coolant problems with my MK7 GTD

[AHugg987]

Hello, im writing to ask a few questions about the problems im having with my GTD. The problems that i am having are that when I go on a motorway the oil temp goes up to around 115-120 degrees. This then causes the coolant to disappear the morning after. I have taken it to a few garages and neither of them have any idea what and why it is doing it. Its is a 15 plates car with 85k on the clock. The coolant temp does not change at all and sits at 90 degrees. the full coolant tank is drained after a run on the motorway and requires topping up each time. I can go 6 months by doing 15 min trips to and from work without the coolant changing at all but as soon as i go on a motorway it drains from I would assume the long stint at around 2000 rpm. One of the garages suggested it might be the EGR coolers but wasnt hopful it would fix it and would be charging me around £1800 for a possible fix. I have been considering selling the car due to this issue but would like some ideas on what to do. Many thanks, Alex

 

[misor1994]

Try to make a bypass of the intercooler at the front of the engine. It may be leaking somewhere inside it. I assume you dont see any leakage of the coolant. By making a bypass you will be able to say if it is the intercooler or not. The fuel consumption will rise and the engine power will be lower, so dont be confused.

 

[H4MZ4]

Pretty much the same as me, didn’t notice it locally. As soon as I’ve done 2x 200 mile journeys the tank emptied both times.

I’ve had waterpump and thermostat done recently. Although I noticed a hissing sound from the coolant cap before I opened it, plus it was very loose with no pressure.

Could either be EGR, or a new one I’ve seen is the intercooler.