While my car was having a mechanical problem they told me I had a leaking valve cover which they wanted to replace for $310 plus $150 for the tensioner o-ring and 190 $. on a new Poly-V belt. Forget it! I do it myself So I researched what to buy and how to do maintenance. After purchasing all of the above parts plus a new PCV valve, I spent less than $75. The hardest part of replacing the valve cover was removing the old accumulated oil. Plain green has worked wonders here. A few hours later all parts were replaced and the car started again.