i have a 97 range rover 4.0 se , i only have it for 1 month and since last week everytime i use it i hear a knocking noise on the right side of the engine ,,

 

How many miles on the engine and when do you hear this knocking noise, hot, cold, all the time, under load give us more information?
Mike

 

it has 103,xxx miles and i only hear it when the engine is already warmed up,, coz when i start the engine in the morning it sounds good but after i drove the car it sounds like a diesel engine,,

 

At that mileage, it is hard to say, could be a rod knock, rocker arm/ lifter problem. What ever it is, don't continue to allow it to happen, really need to let a shop look at it.
Mike

 

i saw a post in this forum, that they just put a valvemedic treatment or do the engine flush and it mkes their engine quiet,, is it really a good idea or can it give more problem to the engine??

 

To do an engine flush will not hurt an engine, but if you have a mechanical internal engine problem, it will make it more obvious. For the most part this is considered a good thing to do once in awhile to keep your engine free os sludge build up and the problems this can cause.
Mike

 

The post you refered to was one where Mike and I cover most all possibilities of a "TICK". I took the entire top and bottom ends apart on my engine and cleaned it by hand. The valvemedic was temporary at best to at least thin the oil enough to suck through the plugged screen. I also had a different tick that only started after the engine warmed up. This ended up being the passenger side cat.