Strange Growling Noise

[Tron20]

Ok guys n' gals, here's a question for you, today my lexus was perfectly fine, driving as smooth and quietly as it ever has. I took it for an MOT, was with the car all the time, the tester used a rod to hold the accelerator down to do the fast idle test, and left it at 2500 rpm for 5 minutes or there abouts, during which time the revs did go up to 3000 rpm, and it sounded a little louder, but I thought nothing of it. Anyway the car passed with no problems as usual, een emiisions were spot on.

Now the problem is when I drove off I noticed and annoying noise, well more of a louder exhaust note when accelerating. The noise occurs at 2500-3500 rpm, but can be heard through the rev range a little, but its more prominant around 2.5k. I suspected a hole in the exhaust has now opened up, and I took it to severa exhaust places for them all to tell me "I can't find anything wrong, and I can't hear it"

Has anyone experienced this before on thier cars, is it a hole in the exhaust, or could it be as one of the places suggested that the gubbins inside the cat have come loose and are rattling about? I'm puzzled and frustrated. I'm even taking it to the main dealer tomorrow to have it checked out, its concerning me that much

Just to clarify though, it does it when the gearbox is in neutral aswell as when its in gear, but its louder when under load and pulling the car, which makes me think its a hole. I can see this is likely to cost me a fortune to put right, but any ideas would be much appreciated.

Paul

[Tron20]

Nice, found out what it was, lexus found it straight away. The stupid mot tester had put the car on his ramp, then jacked up against the thin crossmember at the back of the engine, and crushed it into the cat, hence the vibration an louder noise when accelerating. Lexus couldn't find anything else wrong with the car, but regardless it was £40 for the mot, and £52.43 to straighten the bar and inspect the rest of the car.

Paul

[Sagitar]

Nice, found out what it was, lexus found it straight away. The stupid mot tester had put the car on his ramp, then jacked up against the thin crossmember at the back of the engine, and crushed it into the cat, hence the vibration an louder noise when accelerating. Lexus couldn't find anything else wrong with the car, but regardless it was £40 for the mot, and £52.43 to straighten the bar and inspect the rest of the car.

Paul

. . . . and are you doing anything to recover your costs from the incompetent MOT station?

[Tron20]

I'm thinking about doing so, but the bloke is just likely to deny he did it, then the ball will be in my court to prove it. However you can clearly see where he has jacked the car up on the crossmember.

What do you think I can do about it?

Paul