Recently bought a 2004 Sonata from a local dealership. It runs great and looks nice. I recently noticed when the car is on there is a noise coming from under the hood. Not sure exactly how to describe it, but it's almost like a sputtering noise. It's more clearly audible when the passenger window is rolled down and I accellerate. Just wondering if anyone has any hunches as to what this could be? Also wondering if I should take it in very soon to avoid something bad actually happening or if I'm fine driving it for a while longer. None of the lights on the dash are on at the moment either.

Do you feel any loss of power during the "sputtering" ? Anything? If not, probably is something with your exhaust system, check for corrosion or a hit throuout the exhaust pipes.
If I remember correctly, the exhaust system runs somehow on the right side of the car (I believe) and I would suggest checking everything from the manifold / header to the Cat converter to the Silencer (resonator) to the Muffler.

Also, check the hoses, when you accelerate the radiator fluids flow faster and with more pressure, a bad hose could be making the noise. Check the Raidator cap and have the Radiator checked for any possible leak.

However, if you feel power loss, might be a bad sparkplug or cable.

Good luck.

This post has been edited by EF/ELP: Sep 13 2008, 04:54 PM

Which engine do you have? and how many miles on it?