2006 Impala, dealer negligence?
Not sure what you mean from a faint knocking. Faint Knocking noise refers to piston slap till the engine warms up and a Tapping noise refers to a noisy lifter, if it's a bad lifter. The noise would get louder as the engine's RPM rises. Most GM owners have the problem of Piston slap first thing in the morning when the engine is cold, it's common and was made that way. The tolerance clearance between the pistons and cylinder walls are quite large since the majority of people do not warm up there car, so as you get on the gas and the pistons expand to the right size and will not wear out the cylinder walls giving the engine a longer life. The side effect to this is piston slap till the piston expands, that's why they say that you just have to warm up the engine for 2 min and then drive. Personal I'm not one to get in and drive, I'll always warm up the engine enough to see the temperature gauge go up. My wife has a Montana with over 150.000 miles and no piston slap after the first oil changed. I found that adding some Lucas engine oil treatment and a can of Engine Restor every second oil change has kept the engine running smooth and quiet, And about 500 miles before the next oil change. I add a bottle of Marvel Mystery Oil, the Mystery oil is thinner and will clean out the internal oil journals to the crank shaft and lifters which would cause the noisy lifter if the oil passage ways are sludge up. The Mystery oil will also clean the Oil Pump Pick Up Screen, ensuring there is not oil restriction in your engine. I have a GMC jimmy with over 350.000 miles and engine still running 100% with this method of service. Good luck and if your due for an oil change soon, add the Marvel Oil and a few days later change the oil and filter and add a can of Engine Restor and some Lucas oil treatment. This should quiet down your engine and add a few more years to it's life. Keep me posted, be glad to answer any more questions you may have.
Nov 13, 2009 |
2005 Chevrolet Impala