Volvo has started to say it's overheating after driving it 2-3 miles. When I stop it the reservoir is bubbling but temp gun only shows it at 155°and upper radiator hose only shows 190°, lower at no more than 120°. No oil in coolant or any milky oil anywhere, and no change in oil level. Cap doesn't blow any coolant out, fans are all working, good heat exchange through radiator. Replaced bad thermostat. No change... Any advice. Changing water pump tomorrow.?

 

What engine?

 

3.2 and my bad, it's a 2008
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3.2 and my bad, it's a 2008
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