I have a 2012 Impala LT w/ 39,800 miles. The first week & first tank of gas this noise wasn't apparent. Now, there's a metallic or almost bell sound "ringing" when accelerating or engine under load. Sometimes you don't hear it and then it re-appears. I did put 93 octane w/ that NOS octane booster in the last tank. Could this have caused this noise? I had a mechanic hear it today & he said that it might be in the transmission but not sure until they really look at it. This car is and was a GM re-certified used car. I just bought it from a Toyota dealership. Please advise.
My car has 39800 miles.
My car has an automatic transmission.
Hi there. If I had to guess, based on your inquiry, my first thought would be to check your oil level, as commonly this type of noise is related to a lack of lubrication in the cylinder heads and the "pinging" noise is caused by lifters that are rubbing without proper lubrication. However, using 93 octane gasoline in a Chevrolet Impala along with the added "NOS" fuel additive could also create this type of pinging noise. Many of today’s fuel additives are filled with copious amounts of catalyst (or metals) that help in the ignition of gasoline. The reality is that normal gasoline only burns at an efficiency rating of maybe 80%. The rest of the unburned fuel is expelled out of the exhaust as "emissions". The additive can cause the ignition of fuel in the combustion chamber to fire slightly before TDC, which does improve the efficiency of the burn but it can also cause an engine ping. My advice would be to check your oil level first, start using 89 or 91 octane fuel, no additives and see if that solves your issue.
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