G35 coupe engine knocking

[AceDudda]

I have a G35 coupe and my engine is knocking while the car is in idle and on and off while driving. I'm in a small town so most mechanics don't know or want to touch my car; but one mechanic said it's probably knocking because I've been using 89 gas in my car. His suggestion was to put 93 and the knocking should stop. My question is if I've been putting 89 in my car for about a year now would this be the cause of the knocking and if so is the solution switching back to 93 gas? I only have 56,000 miles on my car and I get frequent oil changes and just change my transmission fluid.

[Q451990]

to NICO!

Lower octane gas will usuall cause a knock under a load - not at idle. What year is your G? Do you notice any oil consumption between oil changes?

Heath

[AceDudda]

2005, and I do not do my own oil change I get it done at Avis Lube.

[MoonRivertttt]

I am thinking the knock sensor has gone bad.

[audtatious]

Take it to a auto parts place and have codes pulled.

[ImStricken06]

help us help you:

1. Post a video please with clear audio.

2. Any CEL's? (check engine lights)

3. Any oil consumption? ( have you been keeping an eye via the dip-stick?)

4. Any blue smoke from the exhaust pipe?

5. any chatter upon start-up? (the synonymous timing chain noise)
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your 3.5L is known for oil consumption. running low oil levels will cause deadly internal engine damage. if your not adding oil to your engine, your going to get worn piston slap, valve train noise, or worn/spun crank bearings that will cause the crankshaft to 'dance' in its bearings.

is this the noise?

[youtube]http://www.youtube.com/watch?v=DvmlchfBaE0[/youtube]