Engine help

[savageman25]

My mates got a mk2 ford granada 2.3 v6, he bought it off one of his mates for banger racing as his mate said that the head gasket had blown and we were going to put a 2.8v6 lump in, thing is though, is that we gave it an oil change and had a go at getting going just incase the original owner was wrong about the head gasket, after a bit of persuasion the engine fired into life, ticking over lovely and revving real nice, no creaming of the oil, no horrible smoke from the exhaust, we had it running for a good 30mins-hour just tinkering with bits a pieces making it run spot on, so two days later my mate went to start it again, nearly as soon as the car started the engine, it was backfiring,miss firieng,eratic idle speeds, and lots and lots of white smoke from the exhaust, im just wondering what could have caused an engine tht was running sweet as a nut to be a dud two days later.
I no alot of you would be saying whats the point seeing as its a banger, its just that the 2.3l v6 ford engines are really hard to come by these days and are in my opinion very good engines. (apart from fuel costs lol)

[mark christopher]

sounds to me like you have a head gasket/cracked head, when its been stood the coolant pressure has pushed coolant into a cylinder. does it clear arter its been warm?
changing oil, wont fix a head gasket?
emulification wont occur instantly and is not alllways a sign or water getting into oil or head gasket failure. head gaskets fail in many ways

[savageman25]

Nope it dont change at all after its warmed up, it just seems to get worse.
You must have misunderstood as well about changing the oil, we thought that the man who we bought it off may have been wrong about the head gasket as h isnt that good with cars
The reason we changed the oil was the car had been sitting a while,probably about 6 months and when we checked the oil it was a nasty pale brown color and even us banger boys no that thats **** oil