Browse over 9,000 car reviews

What could be causing thick exhaust smoke from my 2003 Nissan X-Trail

What causes thick exhaust smoke from my 2003 Nissan X-Trail? It appears on first start and disappears after a minute.

You can tell a lot about exhaust smoke by its colour. If it's a blue-grey colour, the smoke is probably from burnt oil. If it's black, excess fuel is probably the cause. Make sure, too, that what you're seeing is not just water vapour that is a normal part of the combustion process and will disappear as the exhaust system heats up and turns that vapour into steam (which is invisible).

But if it really is blue smoke you're seeing, it could be a case of worn out piston rings, or worn valve guides or seals. If it's black smoke, you could have a problem with injectors, the fuel pump, intake system, spark plugs, any number of sensors that control the engine's fuel:air mixture, or about a thousand other things. That fact that the smoke disappears after a while suggests that the engine is happier when it has some heat in it, but really, it shouldn't blow any smoke of any colour at all.

Disclaimer: You acknowledge and agree that all answers are provided as a general guide only and should not be relied upon as bespoke advice. Carsguide is not liable for the accuracy of any information provided in the answers.

Comments

Have a new question for the CarsGuide team?
More than 9,000 questions asked and answered.
Complete guide to Nissan X-TRAIL 2003
Complete guide to Nissan X-TRAIL 2003 CarsGuide Logo
Reviews, price, specs and more