I have also noticed something similar in my 2.0 litre Bongo when hill climbing at high revs. It has always sounded like something attached to the engine or drivetrain that is not screwed down properly and vibrating. Normally a slight change in accelerator position cures it. Couldn't find anything lo...

sorry but has been rehomed.

Thanks for the welcome, hopefully somebody needs one.

From a year 2000 Bongo. Fabric is in great condition. Please note that the lapbelt in the pictures is not included, but bench does include rails and plastic foot trim. New owner must collect. I am in Coleford, near Radstock, Somerset.