Having bought a (cheap) 1971 camper last year (no MOT, very 
poor state of repair) we spent the whole winter fixing it up to 
get it back on the and painting/tidying it up to make it look pretty. 
We finally finished and passed the MOT last month and were quite 
pleased with our efforts. We've been driving it around for a bit and 
everything appeared to be fine until yesterday. My wife was setting 
off going up a fairly steep hill when the whole van started to judder 
violently and smoke poured from the heater vents. I guessed the 
juddering was something to do with the clutch but what about the 
smoke? Where did it come from and why was it gushing out from the 
heater vents? Should I be worried? Any help with this would be 
greatly appreciated.

                        Cheers
                                Jon.