Nissan Repair: Variable Valve Timing, rump rump, variable valve timing

Question
I have a Lexus es300 1999.   They are telling me i need a timing valve?  Can you tell me what this is and why I would need this.  What I have read sounds like it is just for better fuel preformace?  I took it to the shop with a problem that felt like water in the gas?

Answer
Deb,

If you remember old hot rods that had a lope at idle like rump, rump, rump?  Anyway, that was a race cam making the engine lope.  Bring technology to automobiles and you get variable valve timing.  So, you have a race cam, but at idle it retards so the car will idle nice.  Anyway, the way they get the car to have such nice power and fuel economy is with a valve that advances and retards mechanical timing by the use of oil pressure.  If the valve gets plugged or if it just wears out it will need to be replaced for your car to run properly.  I use exclusively synthetic in my cars for this reason.  I know Nissan and most Japanese manufactures do not recommend synthetic oil I use it to keep things clean.  As bad as it is, I would get a second opinion, like the Lexus dealer, to verify the variable valve timing valve or valves need to be replaced before I would spend the cash.  The dealer should charge no more than $100 bucks for the diagnosis.  Their scanner and a few minutes with your car and they should know one way or the other.