Hello Guys,

I have very weird issue with my car. So when driving on wet road and when stop I get quite loud knocking noise coming from the front of the car. It almost sounds like the cog wheel grinding, but it is loud (even my wife noticed the noise). It's there for few seconds and disappears. Not sure if it comes from driveshaft, transfer case, gearbox, but it's ony happening in wet conditions. I have 2.5 v6 petrol model. It probably has nothing to do with that, but the noise came on shortly after I had full stainless steel exhaust fitted. Any help will be much appreciated. Many thanks,

 

Chris, I would be looking at the heat shields on the exhaust manifolds. They are known for creating a knocking sound as they get older. Having the exhaust done, these I sure got moved around and odds are will be the source of your noise. After that, I would be looking at the heat shields near all your exhaust components. Could be some of them are now much closer than they were and may be touching in certain conditions.