Mk 3 1.6 ecoboost knocking sound

[Bulk]

Hi, looking for some pointers for diagnosing a knocking sound which sounds likes it in the engine bay area.

Under idle there is no knocking. When i rev the engine at idle there is no knocking sound.

However, when i start to accelerate a knocking sound starts and it gets worst the more i push on the accelerator. 

On the motorway at a set speed on cruise control or manually applying minor throttle to maintain speed there is no knocking but if there is a small incline then you get a gentle knocking as accelerator is applied to maintain speed which increases the more the accelerator is pressed.

Any thoughts? Cheers!

[mastachaz]

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[Bulk]

A bit more information since saturday.

I would describe the sound as a knocking/rattling sound. It only occurs when the accelerator is pressed beyond 10% and only when driving, it doesnt do it when you rev in neutral. 

You can accelerate to a given speed with 10% throttle or less and sit at a set speed and not hear anything. As soon as you step on the accelerator beyond 10% you get the rattle/knocking which is worst the more you step on the throttle. 

No sounds sitting at 70 or higher for that matter on cruise control unless climbing an incline and then you hear the knocking sound as the car adds throttle to maintain speed... so its not pedal related as it does it on cruise control but only when on inclines where a certain amount of throttle is required to maintain speed. General motorway driving where only minimal throttle is required to maintain speed theres no knocking sound.

Hope i have described that well enough. 

[Htpearg0]

Sounds Like Pinking . Have you checked for and codes?

 

[Bulk]

Thanks for the response. Im not convinced its pinking based on the examples ive just checked on youtube but im not an expert so it could be that and it just sounds different.

if i could better describe what im hearing its like sticking a pencil into a moving fan and the throttle amount is the amount the fan spins. So the knocking is faster the amount the throttle is pressed and at less than 10% throttle theres no noise.

The car is going to the garage this afternoon so i will update. I was just curious before it went in.

[Bulk]

Just an update. The garage have the car and they suspect a leaking fuel injector seal. Work being done under warranty as engine is a replacement due to catastrophic failure before the cooling system recall currently active. Will update further once its fixed!

[south_bound]

Hi, did this noise happen only within a certain rev range or at all engine speeds?  Sounds exactly what I am experiencing at revs below 1500 or so, except that mine is a diesel engine!  I can't see any evidence of leaking injector seals and can't find any leaking hoses which was my other thought.  Let us know how they deal with the leaking injectors and if that fixes it.

[Bulk]

Hi mate. I didnt notice it at any specific rev range, purely based on throttle position.  For example, i had it up to 5k revs applying a small anount of throttle and had no noise, but have had noise at low revs applying more throttle. Will update when its fixed if it was definitely injector seals.