I have a 2002 Nissan Altima. There is a rattle in the top end of motor when the car is idling and also when gas is applied(sound gets louder). We had an oil change and they said we needed to replace our timing chain, could that be causing the rattling? The car has not been drove in 2 months. Also how serious is this problem?
You should get a second opinion. The timing chain can make noise, but it isn't a rattle usually. If you have the overhead cam engine, it could be lifters or a loose rocker. It takes a trained ear to recognize the difference.