rasp and knock under acceleration

OSI

Hello,

For the past few weeks, my car (03 Hyundai Coupe 1.6) has been making a loud rasping, scratchy noise under acceleration. It initially made the noise between about 2-2,500 RPM, but it's now making it across a lot more of the rev range, and will eventually stop if it gets past about 4,000 RPM, or if I ease off the throttle a bit. This occurs less once the engine has heated up, and isn't consistent, but does happen often enough, and doesn't happen under low acceleration or when idle/cruising.

And now today, I find that if I start accelerating from anything below 2,500 Rpm, when I first touch the accelerator there is a sort of knock/pop noise that only lasts for a second. It's like the noise that metal makes when you bend/pop it. The engine looks visibly OK, isn't down on power (what little of it, it has) and isn't eating oil. Climbed under the car this evening and every thing looks ok, apart from this part below, that's part of the exhaust. Anyone know what it is and if it's likely to be the cause?

Captain Slow IRL

That is your flexi-joint on the exhaust - it doesn't look like serious damage, there would be black sooty deposits if the exhaust gases were leaking out through it.

Is the noise still there with the car at a standstill and engine revving or is it only when the car is moving?

bbability

Where is the noise coming from? If its the engine compartment its more likelly a belt or pulley that's needs sorting.

Avns1s

Look for a loose heat shield.