The sound appeared to be coming from under the car somewhere between the catalytic converter and the exhaust manifold.
After reading all the posts here and researching a bit on the internet, I thought of all the usual suspects.
- Exhaust manifold
- Gasket
- Heat shields
- Pinking
- Faulty knock sensor
- Vacuum leaks
Couldnt feel any leaks around the manifold. Car wasnt noisy when pressing the accelerator smoothly. Only when pressing the pedal hard down quickly or on full acceleration when moving.
Took it to garage - They thought it was that the centre box muffling had gone. I wasnt convinced as the exhaust is only 6 months old.
Worked out the problem today
The clamp/flange that holds the flexible exhaust downpipe to the exhaust manifold had become loose. Tightening it up sorted the problem.It's purring again instead of sounding like the engine was trying to slam its way out of the sump !!!!
Just posting this in case anyone else gets a similar problem.
