2000 Porsche Boxster Cutting Out

[Ray55]

Hi All, bought an old 986 a little over a week ago. Put 1Ltr of new oil in the car when problems started. It began to overheat when in slow traffic and cuts out when approaching junctions etc - oil light flickers, revs reduce then cuts out.

Been in garage, had oil change + new filters. They thought it may be a blockage in cooling system - but doing it again.

Any thoughts please?

[svandamme]

Does it run properly if you drive it normally, eg if you do not get stuck at red lights or Traffic?
That would be an indication that cooling works, but the fan is not working