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Discussion Starter #1
I noticed today when I floored it to get on the interstate that at about 4000 rpms it sounded like the valves was rattling. The car runs strong and has low miles. You dont hear anything in any other part of the rpm range exept right before it is going to switch gears when getting down on it. Has complete tune up done recently along with oil change. Could it be that I need a valve job with such a young engine? If I did need a valve job would you only hear it at high rpms or all across the rpm range. I was also wondering do you think it would be worth it to go to synthetic oil. Appreciate your input..
 

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First thing that comes to mind is your detonating. Spark knock, pinging, detonating...whichever you choose. What's your timing set at and what octane are you putting in it?
 

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Discussion Starter #3
Timing set

The car is set at ten degrees on the timing or maybe lower but Im positive its not set high and I generally use 89 octane and even when I do use 87 Ill put in fuel additive. This is only been recently that this has started, around the time that I put in the 3.73 gears. Would engine knock occur only at the end of the rpm range.
 

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@10* 87 octane is fine and doesn't need additive. If you're using higher octane you should adjust your timing else you're wasting your money. Even with 87, depending on the engine, some people have gotten timing to 14*. Put in 87, time it until it starts pinging, then remove 2*. Stick with 87, as there is no need to put in more. The gains are scant at best.


Whether this is what is causing your problem beyond 4000 RPMs I am not sure of. But I am sure you're wasting your money on higher octane fuel and additives.
 

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I've told this story before but in short, my buddy works at a dealership. Last time gas went so high they bought a machine to measure gas quality to help diagnose fuel problems. Some vehicles showed as much as 20% ethanol. Kinda like the cocaine that hits the streets in Miami aint the same as the stuff that gets "stepped on" as it moves inland. I'd try a tank from a different station for starters. Secondly, pinging is a result of too much compression and or timing and not enough octane. It will manifest itself at the higher spectrum of the RPM band. You can pull timing or raise octane. Have you checked your fuel filter lately?
 

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I've told this story before but in short, my buddy works at a dealership. Last time gas went so high they bought a machine to measure gas quality to help diagnose fuel problems. Some vehicles showed as much as 20% ethanol. Kinda like the cocaine that hits the streets in Miami aint the same as the stuff that gets "stepped on" as it moves inland. I'd try a tank from a different station for starters. Secondly, pinging is a result of too much compression and or timing and not enough octane. It will manifest itself at the higher spectrum of the RPM band. You can pull timing or raise octane. Have you checked your fuel filter lately?
Very true we do have the best coke around LOL...

But for real, check your plugs as they have a wealth of information on them. Also that is a good idea about the gas quality as ethanol is not friendly on older motors.
 

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Detonation at low loads is usually mistaken for valve train rattle.

But at 4k and WOT I would think you'd hear an audible ping.
 

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Discussion Starter #8 (Edited)
Appreciate the advice, Im going to check plugs as soon as possible. As for the fuel, I always go to this small little gas station out of my way just because of the sign out front. 100%PURE GAS,NO ETHANOL. And also will check the fuel filter but even though its pinging at high rpms, it doesnt studder or none of the above. If it wasnt for the flowmasters you couldnt even tell it was running, theres no loss of power or missing at all. But Im going to check them plugs and probaly replace them to see if it helps. She likes copper right? What would occur if the timing is set to low and Im using higher octane 89 (no ethanol). Im going to play with the timing, Increase to I hear pinging, then decrease 2 degrees right?
 
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