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Stephen Rothwell
Stephen Rothwell,
Category: Nissan
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Experience:  Director at Steve Rothwell Limited
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I have a nissan qashqai diesel it jst failed nct on smoke

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I have a nissan qashqai diesel it jst failed nct on smoke test reading at 9.9
JA: How old is the engine? And when was it last serviced?
Customer: 08 last serviced in june
JA: What is the model of your '08 Nissan?
Customer: Nissan qashqai 1.5 dsl se
JA: Are you fixing your vehicle yourself? What have you tried so far?
Customer: Nothing im only back from nct
JA: Anything else you want the Mechanic to know before I connect you?
Customer: Iv read about changing oil n filter and basically flooring it for about 30 mins before retest to clear out any soot


Thank you for your question, my name is ***** ***** I am a fully qualified vehicle technician with over thirty years in the trade, hopefully I can help.

If you do normally use your Nissan for quite short runs, the soot can build up, in this case the advice you have heard should clear the exhaust and lower the reading. This would preferably to take the vehicle for a run of half an hour or so keeping the revs high, so possibly keeping it in a lower gear than you normally would. This should clear out the system.

If this does not work then the problem may be with a leaky injector or other fuelling problem, but if the engine appears to be running ok, with no problems during normal use, then giving it ia run should clear the systems.

It would also be a good idea before taking it for the run to add a fuel additive like this one (click the link)

I have found This has proved very effective.

I hope this answers your question, but do please feel free to ask any further details by replying to this thread

If this does answer your question please click accept and rate me, this allows me to continue, even

after clicking accept I can continue to answer questions on the matter by replying to this thread

Many Thanks


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