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While exploring the Service Manual, I ran across this component that sits between the intake manifold and the engine valley cover. It appears to cover the high pressure fuel pump and the tubes that extend from the fuel pump to the fuel rails. It would appear, from the caution note, which says "The noise cancelling foam component MUST be replaced if it has been exposed to engine fluids. Failure to replace the noise canceling foam component that has been exposed to engine fluids may result in an engine fire resulting in catastrophic engine damage, and possible injury or death." that its purpose is to reduce noise.
I thought it might be of interest to some because we see, or used to see, reports of the a sewing machine tic-tic sound which is usually attributed to the high pressure fuel pump and/or the fuel injectors. This component may have a role in reducing the noise that is heard. It appears in both the Coupe and Convertible. The part number is 12698115. Surprisingly there are several for sale on ebay too.
Below are some images, one showing the underside with appears to be molded to cover the fuel lines. It does not completely cover the fuel rails.
Last edited by Andybump; May 24, 2026 at 05:56 PM.
I'm tryin' to get my garden finished. I was on schedule but then a series of unforeseen circumstances and a extended period of rain set me back. So, I'm still out there, now in damp and mud and...... finishing up - sometimes I check the forum when I'm taking a break.
While exploring the Service Manual, I ran across this component that sits between the intake manifold and the engine valley cover. It appears to cover the high pressure fuel pump and the tubes that extend from the fuel pump to the fuel rails. It would appear, from the caution note, which says "The noise cancelling foam component MUST be replaced if it has been exposed to engine fluids. Failure to replace the noise canceling foam component that has been exposed to engine fluids may result in an engine fire resulting in catastrophic engine damage, and possible injury or death." that its purpose is to reduce noise.
I thought it might be of interest to some because we see, or used to see, reports of the a sewing machine tic-tic sound which is usually attributed to the high pressure fuel pump and/or the fuel injectors. This component may have a role in reducing the noise that is heard. It appears in both the Coupe and Convertible. The part number is 12698115. Surprisingly there are several for sale on ebay too.
Below are some images, one showing the underside with appears to be molded to cover the fuel lines. It does not completely cover the fuel rails.
Recall with the C7 the noise insulator was a thinner. There were posts of it not being held fully across the bottom of the intake manifold. That would make the high pressure mechanical pump loud. Looks like for the C8 it fits better and probably provides better sound insulation.
Quote Google AI "High-pressure direct injection (DI) fuel pump normally makes a distinct ticking, clicking, or rattling noise. Because it operates at incredibly high pressures to atomize fuel directly into the cylinders, this clatter is completely normal for direct-injection engines."
"The high-pressure fuel pump (HPFP) in a C8 Corvette operates up to 3,600+ PSI (roughly 100 to 250 Bar). This mechanical, camshaft-driven pump is required to step up the low-pressure feed (46–84 PSI) from the in-tank electric fuel pumps to meet the extreme demands of the direct-injection (DI) system."
Just speculation on my part, but since it mentions noise cancellation, I'm thinking it's there to mitigate acoustic loading from the heads onto the pump and fuel lines that could eventually fatigue the joints, causing cracks and leaks.
Just speculation on my part, but since it mentions noise cancellation, I'm thinking it's there to mitigate acoustic loading from the heads onto the pump and fuel lines that could eventually fatigue the joints, causing cracks and leaks.
Agree. That's what it says, and that what I think it does.
Fuel Pump Insulator - What the heck does it do?
Recall with the C7 the noise insulator was a thinner. There were posts of it not being held fully across the bottom of the intake manifold. That would make the high pressure mechanical pump loud. Looks like for the C8 it fits better and probably provides better sound insulation.
