2003 Murano motor clicking

[jasno13]

I have a 2003 Murano. In June 2009 I brought it to the dealership for clicking noise in the engine when accelerating. They said the problem was the front engine mount was broken due to ware and tear. It cost me $450 for one mount to be replaced. Now, I am hearing the same noise again. Before taking it back to the dealership, I had a mechanic take a look at it and there was liquid on the back mount (not oil). I have taken it back to the dealership and they said it is not the engine mount, but an oil valve, there are 2 valves, went bad and it is not reading the oil levels. They told me that it went bad because I went too long before changing the oil. I will admit that my last oil change was 5 months ago, but I can't believe that it would ruin the valve that fast. The oil light never came on. So they quoted me to replace the valve and oil change $450. The same price I paid back in June. Also the mechanic told me that an engine mount for the Murano is 6 years life expectency. And the Murano has four. Can anyone tell me do I believe them? My car is not that old and it is my carpool car. I take to softball practice and pick the kids up from school. So off roading! I need some advice.
Modified by jasno13 at 10:23 AM 10/27/2009