# Engine knock cold mornings



## cdy291 (Dec 8, 2011)

My 2010 Altima 2.5S engine ticks on cold mornings for at least 10 minutes. The last time I changed the oil I put in 5w30 havoline. I dont know that it is all that big of a deal but I guess I should try synthetic in it.


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## smj999smj (Jan 1, 2006)

There's a big difference between an engine "knock" and an engine "tick," so knowing which you have is important. I've heard a few cold start "ticks" that turned out to be exhaust related though it sounded like an engine noise. The synthetic oil shouldn't be necessary nor have an affect on the engine noise.


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## cdy291 (Dec 8, 2011)

I guess tick then.


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## rogoman (Dec 16, 2004)

It appears to be a somewhat normal symptom on the QR25DE; I've spoken with several Nissan mechanics and they all say the same thing that it's probably due to the piston-to-wall clearance being somewhat on the loose side. Once the engine warms up, the ticking goes away. I have a '09 Altima 2.5S that does the same thing; in the summer time, there's no noise during cold running.


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