My rover 75 did this and when i got it looked at it was the air idler control valve not properly connected...any good? When they tightened it up it seemed to run fine for a while but I think it might need replacing after a while as it sort of over revs the odd time. Another guess is a faulty thermostat, and another is the dreaded head gasket problems. Good luck
Amanda
May 2008
Hi Teddi, a common problem is the idle control valve sticking, they get gummed up with petrol deosits, it's an easy DIY job, the valve is on the inlet manifold near the throttle valve it looks like a small coke tin, it's held on with two bolts and an electrical connector, remove it and clean it with spray "carb cleaner" Halfords, don't use WD40 or anything similar as they contain oils that will cause the valve to stick again when the engine gets hot.
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