engine and drivetrain OT: Anybody have any ideas about this car problem?

[Guest Anonymous]

Does the noise only occur while driving, or can you get it to do it parked (not under load)? Its obviously going to be tough not hearing it and seeing in person, but your description makes me think that its something related to the engine torquing. Meaning, components under load(while accelerating) are tight, but when you decelerate things loosen up and vibrate. Like a belt, or bearing, or even a fan. I've seen fans and fan clutches act like that. You might check how tight everything is mounted, check if serpentine belt tightener is working properly, etc. Its a long shot, but it could be related to exhaust. Emission components can fail and cause strange noises.

Dan

[Guest Anonymous]

Ok, my girlfriend and I have a 98 Mustang GT,(ie: it is her car, but I am the one that drives it all the time), anyway it has been acting up a little and I am wondering if any of you have any ideas before I take it to the shop, again. The problem started out that somtimes at highway speed, if you let off the gas, the car would make a fairly loud humming noise that sounded like it was coming from the engine bay. The problem has become increasingly occurant and on part of the my drive home tonight the car made the noise almost every time it the engine unwound around 1500 rpm. I am sure this is the same problem as the highway speed one becuase it is the same noise and the car has really tall gears (70 mph is exactly 2000 rpm). I don't think it is the transmision becuase on the way home I messed with it a little and the sound ocurred in every gear when I let off the gas at 1500 rpm. The only thing is, it doesn't do it all the time (like I said, it did it consistanly for only part of the drive). It is one of those great situations where anytime the car is in the shop the problem suddenly disapears, one guy even suggested, after a test drive, that it was just the tires humming on the asphalt. . . yeah, right, and I need new muffler bearings too. Anyway, if anyone has any bright ideas or even a general direction I could point my esteemed mechanics in I would apreaciate it.

Thanks

Emery

[Guest Anonymous]

The engine reved up for a sec like it normally does when I start it and then as it reved doewn it made the noise for a second.

[Guest Anonymous]

Ford steering pumps are noisy, I've got 2. The air condition pump starts and stops sort of randomly, it may be noisy only when it's off (freewheeling), too. The air conditioner pump may click loudly when it starts, too.