Took the car in for a loose exhaust manifold rattle and the shop guy pressed the brake pedal while revving the accelerator real hard. He said he was "testing" something. Any idea why he was doing this and if it could have caused damaged? Am just wondering. ...Is this normal testing of some kind?

I've heard of drag racers doing this .. letting off the gas and burning out. But no idea why this would be done on a Rover.

 

It's a step in the RAVE manual and of course now I can't find it. ugh...

*EDIT* Found it... Stall Test...
Testing
1. Chock the wheels and fully apply the handbrake.
2. Start the engine and run it until it reaches normal operating temperature.
3. Apply the footbrake and select 'D'.
4. Fully depress the accelerator pedal and note the tachometer reading. The figures should be as given below. Do not carry out stall test for longer than 10 seconds, and DO NOT repeat until 30 minutes have elapsed.
* V8: 2200 to 2400 rev/min
* Diesel: 2600 to 2800 rev/min
5. A reading below 1300 rev/min indicates a torque converter fault, ie stator free-wheel.
6. A reading between 1300 and 2200 rev/min (V8) or between 1300 and 2600 rev/min (Diesel) indicates reduced engine power.
7. A reading above 2400 rev/min (V8) or above 2800 rev/min (Diesel) indicates clutch slip.

NOTE: The figures quoted above were measured at sea level with an ambient temperature of 20C (68F). At higher altitudes or higher ambient temperatures, these figures will be reduced.

 

He was doing a load test to locate the rattle or check for exhaust leaks or blockages. It's hard to monitor an engine under load while youre doing 30mph on the road. You can brake load a car to get it to cause certain running conditions to test.