There is a rattle noise at the top part of the engine for sometime, but now it is getting louder like popcorn inside... do i need to have it opened ? i need suggestion as to why such noise and what is causing all these...before i will have it opened by a mechanic.

Possibly a broken ceramic brick inside the catalytic converter.

sometimes pieces from inside your catalitic converter break loose and make a ticking noise and would be hard to spot without the engine running

Sorry for the late reply but, no, it is not related to a loose heat shield. It is a louder rattling sound more like a loose bearing vibrating inside either the transmission or the clutch assembly. Only between 1600 and 1900 rpm. and it is not present under ou over these rpm. The rattle desappear when I lock the 4X4. Dealer is out of solution!!

Check all of your belts and pullies. Sometimes it helps to remove the belts and turn the pullies by hand. Also run the engine without the belts for a few seconds. If the noise is still there, then it is most likely timing components rattling.

Even the best ears sometimes miss the cause...your starter could be not completely disengaging after starting...(partially sticking into the flywheel) Hope you diagnos before a safety issue. Hope this helps.

Check catalytic converter.Catalytic converter could be breaking up inside.

Have a look at the shrouds around your exhaust system, they are prone to shaking loose and rattle on over run.
Try giving your exhaust a bang ( with your hand when it is cold) and see if it causes the noise . Follow the noise.
Sometimes the baffles fall off inside the muffler and rattle around inside too.
Happy hunting!!

sounds like crank noise....very serious...

but less serious to fix then to fix after it goes.


if could also be the vanos, variable valve timing. but at 2500 i'd say crank, especially if it has that rattle tone. that sound is a wearing connecting rod bearing. when it goes, the engine basically blows up and the insides try to escape through the engine wall...that destroys the bottom end, when that happens, stuff sometimes also goes up into the head, that destroys the top end.

then you would need a long block.

BTW: stop revying it above 2500. you need an engine job....seriously maybe cheaper to get a replacement engine from the junk yard.

check the timing belt tensioner

Check all the bolts and fastenings for the heat shrouds around the exhaust manifold to make sure they are there (and firm). If you can undo them without snapping them, take the shrouds off to check for gravel trapped in that area. It could also be a failing cat converter, but a lot less likely. My next step would be to remove the rocker cover and have a look......