Engine shutdown rattle after EGR/DPF delete – normal behaviour?

[Júlio Rocha]

Hi everyone,

I own an Accord 2.2 i-DTEC (N22B1) which has recently had a full EGR and DPF delete (both physical and electronic). Since these modifications, I’ve noticed a specific behavior that I’d like to run by you.

When I turn the engine off, there’s a very brief metallic rattle/chatter (lasting about 1 second) right at the moment the engine stops. It’s not violent or continuous, just a quick sound as it shuts down.

Key points to note:

• No vibrations or hunting at idle.
• No vibrations or weird noises while driving.
• The clutch bite is perfect and there’s no slipping.
• No clunking when pulling away or changing gears.
• Crucially: If I depress the clutch pedal while turning the engine off, the noise almost completely disappears.
• The car runs very smoothly, and injector values are all within factory specs.

My main question is: could this rattle simply be a result of the engine no longer performing a "soft shutdown"? I know many diesels use the throttle body/anti-shudder valve in conjunction with the EGR for a smoother stop, and I wonder if the delete makes the shutdown more abrupt.

I’d love to hear from anyone who has:

1. A deleted EGR/DPF on this engine.
2. General experience with the N22B unit.

Is this slight rattle considered "normal" under these conditions, or should I be worried about the Dual Mass Flywheel (DMF), even though there are no other typical DMF symptoms?

Thanks in advance for your help!

Note: translate PT-EN with IA

 

[F6HAD]

Sounds like your flywheel is a little out of balance, pretty common and nothing to really worry about until it develops into a knocking at idle.

 

[Júlio Rocha]

Shortly I will post a small video so you can see how it shuts off, with sound. Thank you F6HAD, always helping people. Happy New Year to you and your family!

 

[Júlio Rocha]

Hello! Here is the video. I had just returned from a short trip, meaning the engine was hot. I'm not sure if the on and off noise is normal. Can you confirm? Thank you.

 

[F6HAD]

Sounds ok to me I would say.

 

[Júlio Rocha]

thanks again, FAHAD!

 

[dozi]

Sounds ok to me I would say.

Mine sounds identical and its done 230k miles. Same whirring after ignition off, and its got no issues at all being used daily for both short and long journeys. Some days the car does 20 miles other days it does 700 miles. Love the car, one tank of fuel gets me from the middle of England down to the south of France, they are a great drive!

 

[Júlio Rocha]

That’s right! I had the EGR and DPF deleted a few months ago, and the engine shutdown became noisier. I wondered whether that vacuum valve, which fully closes the throttle and then reopens it, was still working, but I believe it is. Thank you for the help and feedback!