Hi,

I own a 1999 626 lx-v6, auto trans. When holding gas to maintain between 59-64mph (2500 rpm) on the highway, the car engine (assuming its the engine) will make a "humming" sound. If I let off the gas (cruising between 59-64), sound stops. But as soon as I press the gas, it reappears in the above range. You need to listen closely for the sound, but its fairly pronounced at 60MPH and does not seem to affect performance. Sound disappears at 65MPH. It's easier to hear if radio is off/windows are closed. Any ideas?

TY

Hey man, I got a 98 mazda 626 lx 4cyl.
I recently replaced the clutch and timing belt in mine.
It is manual transmission.
You said that the sound is faint, but more noticible with
windows down.
I believe I have the same sound.
I seems like it is coming from the right side of the engine right?
My mechanic looked at mine and told me that it was my
cat. converter.
He said that one of the walls inside it is rattling, no big deal, it will
not do anything to the car.
Go to your local mechanic and tell him what you hear, and that you think it may be either the cat. converter or somewhere in the engine,
and ask him to check it out.

Hope this helps.

Thanks. I will take it to a mechanic.


Hey man, I got a 98 mazda 626 lx 4cyl.
I recently replaced the clutch and timing belt in mine.
It is manual transmission.
You said that the sound is faint, but more noticible with
windows down.
I believe I have the same sound.
I seems like it is coming from the right side of the engine right?
My mechanic looked at mine and told me that it was my
cat. converter.
He said that one of the walls inside it is rattling, no big deal, it will
not do anything to the car.
Go to your local mechanic and tell him what you hear, and that you think it may be either the cat. converter or somewhere in the engine,
and ask him to check it out.

Hope this helps.

No problem man.
:smile:
Good luck.

Quick question, on your 626, did you find the faint sound more pronounced between 59-65mph?

TY

No problem man.
:smile:
Good luck.

No, I have the sound at 2200 RPM at all gears.
It sounds like grinding two metal plates or something.