Water/grey Smoke, Coolant Loss, Overheating

What is the difference between the 2.8 crd and 3.3 Diesel engine in a 2007 Grand Voyager Executive that seems to give rise to comments that the 3.3 is better and less likely to suffer head gasket failure? Is this true? I own a secondhand 2.8 that started to give off plumes of white smoke after forty minutes of driving with a sound of slight misfire at idle - I’ve more or less decided that it’s head gasket having tried all the usual (and steel seal) BUT I have parked the car up for a few weeks and a couple of days ago started it up - the coolant hadn't dropped and the smoke considerably reduced but after twenty mins, the whitish/grey smoke starts to increase at idle but no misfire - is there any other possibilities other than head gasket -
Also - I’ve noticed a very slow drip of clear water from the underside of the engine, drivers side but can’t see where it’s coming from - any else faced these problems and found successful solutions with this particular model -

Hi, just a quick answer but the 3.3 is a V6 petrol.

Head gasket issues are rare with the 2.8CRD in my experience.

Ok thank you - so if head gasket issues are rare - what would be the cause of coolant disappearing and smoke that starts as white turning grey?

Hi,

 

Obviously I can't say it isn't a head gasket but I have owned vehicles with the same engine for years and used to read forums a lot and there was never really much mention of head gasket problems that I recall.

 

First step for me would be a compression test. How bad is the coolant loss? Have you been topping it up a lot? 

 

White / Grey smoke could be unburnt diesel or possibly oil from the turbo as well as coolant. 

 

Clear dripping water could well be normal if from the air con system. I can't remember exactly where it drains from off hand though.