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Hey guys. I have an 18 with around 11k miles abarth. Under WOT around 4.5k rpm there is a rattle noise. The noise is only present under throttle and most obvious at WOT. Same speed if I let off the gas the sound goes instantly away. I only use 93 octane not sure what this noise is. I think it’s more prevalent with the top up.
 

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It's probably just chunks of your piston skirt hoping on top of the piston crown. ;-) But on a serious note, the most likely source of your problem is a lose heat shield on part of the exhaust; either at the header or potentially lower. We saw this pretty often at Jiffy Lube and would always tighten and fix if possible during the signature service. Double check your heatshields and tightness of bolts to see if that's it.
 

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It's probably just chunks of your piston skirt hoping on top of the piston crown. ;-)
Nah, that sounds more like a metallic whirring blender as the piston pieces are sucked through the turbine and out the exhaust.

74585
 

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Discussion Starter #4
It's probably just chunks of your piston skirt hoping on top of the piston crown. ;-) But on a serious note, the most likely source of your problem is a lose heat shield on part of the exhaust; either at the header or potentially lower. We saw this pretty often at Jiffy Lube and would always tighten and fix if possible during the signature service. Double check your heatshields and tightness of bolts to see if that's it.
Would that be throttle dependent? I have no noise at idle. I had a boxster with a heat shield rattle but that was a lot more random and less directly tied to throttle and rpm
 

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Hey fine by me. I swung an unlimited mile Powertrain warranty from the dealer.
Welcome and nice car. Looks like mine before the wrap.

Unfortunately that mishap is not covered under warranty. I knew it wouldn't due to everything I had done to it but it was denied simply for not having OEM plugs in it at the time of failure. Quoted me almost $11K to replace engine, remove all modifications, and return to complete stock. Needless to say, I declined and currently working on rebuilding the block with forged internals and a few more CCs of displacement.
 

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@Calehedron Forged low-compression pistons and forged rods would be awesome. You could potentially run 30+ lbs. of boost at that point with a proper tune, larger injectors, and methanol injection.
 

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could be a loose bolt on the piping or something like on an exhaust shield
if it is under warranty just ask them to take a look
 

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Any other thoughts on what this could be?
I've had this exact thing on my car if you are describing a "marbles in a can" sound. But it was with a specific aftermarket Tork tune. It was so uncomfortable to me that I quit using the tune and switched to Eurocompulsion. I've since received an updated Tork tune I'm satisfied with.

I am still not certain and subsequent piston inspections don't indicate any damage but I believe my issue was pre-detonation aka knock. If you are on a stock tune using 93 octane I'm not sure why you would be experiencing that. My advice would be to try different brands of fuel to see if it goes away. I would not put it past any independent fuel distributor to cheat the octane rating.
 
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