knocking sound

I have a 2001 Escape V6 with 112,000 miles that I just put 500 miles on in two days. I noticed a little knocking noise after about 400 miles which increased as the rpms increased. I figured I would check it out when I got home but by that time I noticed the knocking sound had gotten louder. I checked the oil and it was barely on the stick so I added 2 quarts just to make it home. It has been 10,000 miles since my last change and its has always ran synthetic but Im worried there may be some irreparable damage done. Also, when I looked at the pulleys, it seems one of them (compressor I think) is wobbling slightly and could be the making the noise also. The engine has ran the same, performance the same and temp all have stayed the same. A friend told me to put some 20w50 synthetic oil as well as some engine honey and hope that takes the knocking away.....Any advice would be appreciated!! Thanks

Jeff

First things first. This time of year I'm sure you have been operating your A/C on your trip. The wobbling of the compressor pulley indicates to me you have a problem there. It has a piston just like a cylinder and it is probably making the knocking noise. Does it go away when you turn the A/C off? If not that isn't your problem. It's very odd that your oil would be down 2 quarts. Red flags there. Again, as hot as it's been the oil temperature could have gotten so high that it's viscosity got so low that it made the engine knock. I do know that when too many miles have been put on a lubricant it will make your engine knock. Especially if it is hot out. Change that oil and maybe go to a 10-30 or even a 10-40 but stay away from 10-50 and motor honey. It will bog your engine down so much that your gas mileage will suffer. Change that oil and i'll bet the problem will go away.