I have a leak through the front outside rocker cover bolt on the right hand side of the car. Did some research, tried tighten the bolt up a bit as it was quite loose, having tightened it unfortunately it still leaks. Pretty quickly too, started the car and within a minute or two I can see some oil coming up already. The rest of the cover seems to be fine, a bit of sweating but no drips. Do I need to replace the gasket or is there some kind of sealant on the bolt that has gone missing and could be replaced?