My 2003 Mercury Grand Marquis (4.6l) has developed a continuous rattling noise in front when operating temperature is reached and the car is stopped in drive with my foot on the brake. I believe I have narrowed down the source of the noise to the Accessory drive belt and belt tensioner. The rattle disappears when I put pressure (either way) on the belt tensioner. The noise also disappears when the air conditioner is turned off.
Can the tensioner be lubricated or adjusted or otherwise fixed?
REPLACE IT !! Buy a new tensioner it is easy to do, I change them when I change the belt. I just did mine on a 2003 Crown Vic today with
78k. miles and it took less than 15 minutes.Try a blast of silicon spray on the belt and tensioner. I know, the idea of putting lube on a belt is just wrong, but a mechanic shared this with me some time ago - just for the flat serpentine belts. It quiets them down and makes them last longer (anyhow, that's what he said.) Often the noise if from the edge of the belt just touching a pulley and that is the fix. I start the engine, than carefully use the spray. It is easier with the little wand on the can because you can get it right into everything. Load it up, excess blows off, tho.
PoD
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