My 1997 Mustang has a noticeable, but not overly loud knock when accelerating, especially when going up hills. It is not quite so loud when on a flat road. I just changed the spark plugs, thinking that it would be due to spark knock, but I didn't change the wires. After having the plug changed, the sound still continued. I also tried running a higher octane gas (went from 87 to 93), but that made no change. Any help in diagnosing and fixing this would be much appreciated.
This is one of those things that's nearly impossible to diagnose thru the 'net. Could be anything from an alternator bearing to a main bearing. How many miles? Oil change intervals? Spark knock & bottom-end knock sound nothing alike, so if you can't distinguish between the two maybe you have a bud that's into cars & will go for a ride w/you to help nail this one down.....?
63,500 miles, with oil changes every 3,000 miles using Pennzoil 5W-30. It's more of a higher pitched, extremely rapid knocking sound, and it doesn't happen at all while in park/neutral.
Yes, it's an automatic. No, it's not one loud knock. It sounds like a lot of semi-quiet little knocks, rather rapid, probably about 7-10 little knocks a second while accelerating.
Sounds like top-end from what he's describing.....but I've heard belt/chain tensioners & accessory bearings make that kind of noise too....
I know on my v6, after 50,000 miles, the trans like to make all funny little knocks, every think you might be hearing something from the trans downshifting?
