may be wrong on the pressure test on the heater matrix or system but they couldn:t find a problem. but i would say its like an oily smell and also have problem starting when cold up to the point the battery go,s flat. even though the glow plugs have been replaced and fuel filter replaced
the cranking is normal then the battery runs low but the oily smell i think comes through the air vents when the engine is running to full temperature more say 5~10 miles into the journey and thats when i get this burnt metal taste in my mouth . could this be an oil thats been spilt down the side of the engine in the past ? and do you think the battery may not be powerful enough anymore?