Re: Volvo 7.4Gi overheating at idol but not while on plane! Please help!
Could be the heat exchanger needs to be cleaned. A radiator shop should be able to do that for you. Also make sure the coolers (oil and PS) aren't partially plugged.
There may also be a slight air leak on the suction side of the raw water pump. A portion of clear hose at the inlet of the pump would show bubbles. Would have to be in the water for that test, not on muffs.
