Wheat392
Active Member
19 GT Manual 2k rattle
Although this topic has had significant coverage, I wanted to provide both observations discovered during diagnosis and my theories based on those observations. I performed a series of tests to help determine the source and rule out other potential sources.
Tests:
· lock all 4 cam phasers by disconnecting them and running the engine, creating the same rattle. No change still 2k rattle.
· Isolated each phaser by disconnecting, recreated the rattle then shut the engine off, reconnected and disconnected another (resets the computer so the next phaser is isolated). No change still 2k rattle. These two tests help to rule out the timing and VCT system creating the rattle.
· Stethoscope on the high-pressure fuel pump. No noticeable link to 2k rattle noise.
· Power balance test by disconnecting each coil and recreating the noise with no change in the 2k rattle. This helps rule out piston slap or rod bearings as the 2k rattle would change characteristics based on being down a cylinder. Not saying it would go away, just would create some kind of change.
· Hooked up a multi-channel automotive stethoscope, These use microphones on a clip hooked to a box with headphones. It allows you to switch channels while creating the noise to isolate its origin. The following areas were tested with the results listed. All were reviewed while creating the 2K rattle. (Steelman 06600 Chassis Ear)
· Rear dif - no noise
· Trans x member - small echo
· Rear trans - medium echo
· Bell housing - loud knock – Location of flywheel / clutch.
· Engine block - slight echo
· Clutch hydraulic line – with clutch pedal out, throw out bearing not contacting clutch no noise, clutch in, throw out bearing touching clutch loud noise. When raising and lowering the clutch without listening to the stethoscope, outside noise is unchanged. When the throw out bearing contacts the clutch, the noise travels through the fluid / lines and is a very clear distinction between engaged and disengaged. This test also made no difference on the mic hooked to the engine suggesting again, its not an issue with the engine, piston slap, etc.
Multi Channel Stethoscope
· Placed an inspection camera up through the bell housing drain hole, documented video of outer dual mass flywheel moving with the inner flywheel not moving. This created a similar version of the noise. See linked video.
· Engine can be completely warm; noise is louder until you drive and heat up the trans / clutch. This suggests that, because the noise is consistent engine cold or warm, as long as it has not been driven, the clutch / flywheel are cold making the same noise. Drive it, warm up the clutch / flywheel and it gets quieter. My theory is heat softens the dampening material reducing the noise.
· Notes on the engine. 4 oil changes so far, no metal in oil filters, each one cut open. Compression is consistent across all cylinders. Small amount of cylinder scoring found in #5, no difference in compression to the others.
With the above info, it seems more likely this rattle is caused by the dual mass flywheel added to 18 and up manual mustangs to avoid high RPM lockout. Failed dual mass flywheels (many examples on YouTube) make a similar metal on metal rattle noise. See link: This also shows the 2 failure modes for a dual mass, rotational freedom and the ability for the 2 plates to touch. Go to 1:31 in linked video to see example.
I went to my local Ford dealer. Got a set of keys to a 2019 manual GT. It made the exact same noise immediately. This car has 100 miles on it.
My conclusion is, the addition of the 2018 and up dual mass flywheel is creating the 2k rattle condition. Replacing the flywheel with a new unit will not cure the noise. Only way this goes away is either 1, Ford releases / replaces current flywheels with an updated design or 2, owners put in a single mass flywheel and clutch, RAM clutches has a kit out already. I would hope Ford comes clean on the true root cause and provides a solution.
Apologies for the novel, wanted to share my thoughts and observations. Always remember these cars are awesome. Enjoy and send it!
Although this topic has had significant coverage, I wanted to provide both observations discovered during diagnosis and my theories based on those observations. I performed a series of tests to help determine the source and rule out other potential sources.
Tests:
· lock all 4 cam phasers by disconnecting them and running the engine, creating the same rattle. No change still 2k rattle.
· Isolated each phaser by disconnecting, recreated the rattle then shut the engine off, reconnected and disconnected another (resets the computer so the next phaser is isolated). No change still 2k rattle. These two tests help to rule out the timing and VCT system creating the rattle.
· Stethoscope on the high-pressure fuel pump. No noticeable link to 2k rattle noise.
· Power balance test by disconnecting each coil and recreating the noise with no change in the 2k rattle. This helps rule out piston slap or rod bearings as the 2k rattle would change characteristics based on being down a cylinder. Not saying it would go away, just would create some kind of change.
· Hooked up a multi-channel automotive stethoscope, These use microphones on a clip hooked to a box with headphones. It allows you to switch channels while creating the noise to isolate its origin. The following areas were tested with the results listed. All were reviewed while creating the 2K rattle. (Steelman 06600 Chassis Ear)
· Rear dif - no noise
· Trans x member - small echo
· Rear trans - medium echo
· Bell housing - loud knock – Location of flywheel / clutch.
· Engine block - slight echo
· Clutch hydraulic line – with clutch pedal out, throw out bearing not contacting clutch no noise, clutch in, throw out bearing touching clutch loud noise. When raising and lowering the clutch without listening to the stethoscope, outside noise is unchanged. When the throw out bearing contacts the clutch, the noise travels through the fluid / lines and is a very clear distinction between engaged and disengaged. This test also made no difference on the mic hooked to the engine suggesting again, its not an issue with the engine, piston slap, etc.
Multi Channel Stethoscope
· Placed an inspection camera up through the bell housing drain hole, documented video of outer dual mass flywheel moving with the inner flywheel not moving. This created a similar version of the noise. See linked video.
· Engine can be completely warm; noise is louder until you drive and heat up the trans / clutch. This suggests that, because the noise is consistent engine cold or warm, as long as it has not been driven, the clutch / flywheel are cold making the same noise. Drive it, warm up the clutch / flywheel and it gets quieter. My theory is heat softens the dampening material reducing the noise.
· Notes on the engine. 4 oil changes so far, no metal in oil filters, each one cut open. Compression is consistent across all cylinders. Small amount of cylinder scoring found in #5, no difference in compression to the others.
With the above info, it seems more likely this rattle is caused by the dual mass flywheel added to 18 and up manual mustangs to avoid high RPM lockout. Failed dual mass flywheels (many examples on YouTube) make a similar metal on metal rattle noise. See link: This also shows the 2 failure modes for a dual mass, rotational freedom and the ability for the 2 plates to touch. Go to 1:31 in linked video to see example.
I went to my local Ford dealer. Got a set of keys to a 2019 manual GT. It made the exact same noise immediately. This car has 100 miles on it.
My conclusion is, the addition of the 2018 and up dual mass flywheel is creating the 2k rattle condition. Replacing the flywheel with a new unit will not cure the noise. Only way this goes away is either 1, Ford releases / replaces current flywheels with an updated design or 2, owners put in a single mass flywheel and clutch, RAM clutches has a kit out already. I would hope Ford comes clean on the true root cause and provides a solution.
Apologies for the novel, wanted to share my thoughts and observations. Always remember these cars are awesome. Enjoy and send it!
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