What is the noise under our van when we do speeds over 50mph?

Every so often we hear a noise under my wife's van as if the exhaust is hitting the chassis. The strange thing is that it only happens at speeds over 50mph, never when going over speed humps or potholes. Our local garage are absolutely perplexed having spent hours on it. Any ideas?

Asked on 1 August 2017 by

Answered by Honest John
It is common for part of the suspension to hit part of the exhaust when the suspension is under compression, which, of course, it never is when the car is up on a four-point hoist with its wheels dangling below. They have to look for damage marks where the hits have occurred and adjust the exhaust hangers or twist the pipe accordingly.
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