Engine noise At initial start, the engine making a noise and gradually stop after 2 minutes of being started. However, during acceleration the noise comes back and eventually stops after I've reached a level speed. The dealership doesn't know what the problem is. I just recently paid $700 for a power steering pump. Otherwise, the car runs fine.

Hi there. There might be a number of things to consider here, but the two worst things (most expensive) that it might be is either piston slap or crank rumble. Now, given that you have changed the power steering pump, it sounds like you might have an external noise and so my advice prior to you having changed the power steering pump would have been to disconnect the pump belt firstly. If the noise was still there, then there is nothing wrong with the power steer system. So you must now do the same with the alternator and A/C pump belts. Have all the belt drives (apart form the cambelt of course) disconnected - if the noise goes away, you have narrowed down the problem area. If the noise is still there, you probably have crank rumble or piston slap. Best way to diagnose piston slap is during the warm-up period of the engine, this is when the pistons are not quite oval and is effectively lose in the cylnder walls. To determine this the most effective way is to play with the accelerator whilst accelerating gently, accerate and then just back-off on the throttle slightly, if you hear the rattling noise, you can play with the sound by easing back on and off the accelerator. You'd actually do the same for crank rumble, but the difference in sound is the crank rumble will sound heavier whereas the piston slap will sound lighter and of higher tone. If that sounds like what you have (either piston slap or crank rumble) then it really is no big deal and I'd wouldn't worry about it too much. If you do think that this is what you might have, then just make sure you are using the right grade of oil and it's a quality oil and all should be fine. Hope this helps. Scottech.

Getting good lubrication flow to the top end of the engine ? maybe some lubrication flow is being blocked to the top of the engine and you hear valve system noise.