Sound under passenger seat on 2004 mercury gran marquis


Asked by Sep 02, 2015 at 06:47 PM about the 2004 Mercury Grand Marquis LS Ultimate

Question type: Maintenance & Repair

It rattles when in idle and gets quicker when i hit the gas, its a terrible clicking
sound under the passenger seat, i am trying to figure out what it could be?

5 Answers


Its not in the car its on the bottom

1 of 1 people found this helpful.

Outside the car, probably a heat shield for the cat rattling Or sometimes an exhaust manifold to muffler leak does really sound like a 'tick' you gotta get under it and look, grab things, wiggle shields, but do it cold. The cat gets way too hot to get near. Wiggle exhaust pipes, and muffler and cat. Nothing should move

1 of 1 people found this helpful.

Louder when you hit the gas? Then it's an exhaust leak. When cold, beat on the exhaust pipes(rubber hammer), converter and such to see if you hear any rattles. Sounds like a blown exhaust manifold gasket to me.


Most likely an exhaust leak, possibly at the passenger catalytic converter outlet. Could also be a rusted through pipe behind the converter.


Could also be a blown out spark plug. Raise the hood with the engine running and see if you can tell where the noise is coming from.

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