I have a 1984 nissan 300c with the 3.0 litre VG30 V6, the heads were

reconditioned about 6 months ago, recently the engine started to blow

large volumes of steam and vapor out the exhaust especially when idling

or driving off from a stop.The cars performance when moving at speed

seems OK. The level of coolant in the radiator does drop quickly with

the engine idling at normal temperature with the cap off, about a cup

full every 10 minutes, there are no bubbles in the radiator coolant

when the engine is running and there is no coolant in the oil in the

sump and the engine has not overheated.Can you suggest anything I

should look at that doesn't require the heads being removed, the inlet

manifold and throttle both have water jackets , is it possible for a

leak to occur there ? the car runs on both LPG and petrol and the

problem is the same with either fuel

Thanks

Country: Australia
Make: Nissan/Datsun
Model: 300c
Year: 1984
Engine: VG30