Frequently asked questions
Q. I have a 2003 Mondeo TDCI that has been spewing out thick black smoke whilst cold & although it starts it doesn’t always accelerate. Once warm the car drives like a dream. I took it to a garage that specialises in diesels, injectors & pumps. They put it on a machine. It said no faults, despite filling the workshop with smoke. They then took the injectors off & tested them. Two came back with a fault so they reconditioned them & cleaned the other two, but this still hasn’t fixed the problem& the bill currently stands at over €500 and they don’t know what it is but want to run more tests. Do you have any ideas?
A. Black smoke in a Diesel is either too much fuel or not enough air. As you’ve had the injectors checked they should be ok. ‘Fuel’ could also come in the form of engine oil via a leaking turbo seal on the inlet side, but you say it runs fine when hot which seems to rule that out. I would personally check the EGR valve and it is very common for them to become completely obstructed with carbon which means they are then not opening and closing correctly.
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