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tech0405, Technician
Category: Car
Satisfied Customers: 10741
Experience:  Certified technican 10 years experience
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2002 Infiniti I35: lowest octane mechanic

Customer Question

I have a 2002 Infiniti I35, I have always used the lowest octane gasoline as instructed by the dealership. Recently it has developed engine knock. I took it to my mechanic, he put in an additive which minimized the knock, but did not entirely resolve it. After that tank was refilled, I did not put in the additive and it continues to knock. What is the long term solution. It has 129,000 miles on it..
Submitted: 5 years ago.
Category: Car
Expert:  tech0405 replied 5 years ago.
Welcome to just answer!

have you tried using 89 not 87??
Customer: replied 5 years ago.
Yes I have, in fact I have used the highest octane several times, with no change in the knock
Expert:  tech0405 replied 5 years ago.
Ok we have seen this issue before you may need a valve adjustment but i recommend you have your technician check the condition of the spark plugs and the mass air flow sensor we seen both issues cause this issue where its a pinging knock type noise have him check these 2 things if both check out ok then have him see if the noise is coming from the upper part of the engine which is caused by the valves. I hope this helps.

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