Re: Loud Knocing noise under hood
If the vehicle has been sitting for a while, it's best to put in a few gallons of higher octane fuel. If the spark plugs and wires haven't been changed in the last two years or 30K it's something to look into as well. If that doesn't get rid of the knock then take the vehicle in for a compression test to make sure all cylinders are in good order.
Also; once in a blue moon an oil filter will be faulty and the drain back valve won't function as designed giving a drier start than normal which allows the engine to have more metal on metal contact as oil takes longer to reach the top end.
'00 Durango R/T 360ci 290hp (modded); 138,500m
'06 Pontiac G6 GT 3.5L 220hp; 44,000m
'12 Chrysler 200 Limited 3.6L 283hp; 13,000m
'99 Taurus 3.0L 2V Vulcan 145hp; 154,300m - Traded
Amsoil in all vehicles!