Hi, I had my stearing rack changed earlier in the year, when i picked the car up it all seemed fine. After driving the car around for about 10 minutes or so there was a knocking and rattling coming from the engine bay that I could feel through the pedals. I took it back to the garage the following day and they had a look at it and checked the bolts while I was there. they said everything was tight and couldn't find the problem. I thought it might have been the aircon pipes being disturbed by the mechanic so I packed them out with pipe lagging. It hasn't changed a thing. Is there something the mechanic might have missed or broken?