Just to let anybody who may be interested, I traced and sorted out a clonk from under my 1993 Tempra S i.e. yesterday. (Not today, it's snowing!)
When I started the engine and stopped it there was a definite clonk from under the car and I expected it to be a gearbox mounting. However, it was the little bushes that secure the catalytic converter to the body. The car had a new exhaust system in 2014 but they refitted the old cat. The small metal / rubber bushes had basically separated so the change in exhaust pressure caused a clonk. They are on a thin piece of metal attached to the cat and not removeable.
The solution was to cut a 2 x 5 mm rubber washers from an old rubber bush and use them to take up the gap and fasten the bolts more securely. No more clonk!
When I started the engine and stopped it there was a definite clonk from under the car and I expected it to be a gearbox mounting. However, it was the little bushes that secure the catalytic converter to the body. The car had a new exhaust system in 2014 but they refitted the old cat. The small metal / rubber bushes had basically separated so the change in exhaust pressure caused a clonk. They are on a thin piece of metal attached to the cat and not removeable.
The solution was to cut a 2 x 5 mm rubber washers from an old rubber bush and use them to take up the gap and fasten the bolts more securely. No more clonk!
