Whine while moving

Sheesh. It's been a while.

So, I've recently developed a whining coming from the engine compartment. I would normally try to diagnose it myself, but the problem is that it only happens while the jeep is moving.

Here's what I've tried:

Figured it had to do with rpm's at first. Revving has no effect. While parked and idling, there is no whine. While parked and revving, no whine.

So, I thought maybe it is an axle/wheel issue. Hill, neutral, rolllllling; nothing.

If I am parked, the heap sounds fine. But once I put it in first and let the clutch out, it starts up. It sounds like it is still going on while driving, but the damn thing is so loud in the cab that I can't really tell. (maybe it's quieter) Then, when I come to a stop light it will slowly die down until I come to a stop (even if I roll to a stop in neutral, it will only completely go away if I'm stopped)

I'm at a loss since I can't go into the engine and listen for it. Vacuum lines maybe? I don't really know. (also, it's not the AC)

Any help would be appreciated.
Thanks

Is it related to vehicle speed or engiine rpm?

Have you lifted up or pushed down on the clutch pedal when rolling yet? Just a little to see if that changes the pitch

scottmcneal said:

Have you lifted up or pushed down on the clutch pedal when rolling yet? Just a little to see if that changes the pitch

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Yea. I thought about that. The clutch doesn't change the pitch, but once the gear is engaged, (basically, drive "mode") it starts the humming. If I'm rolling and I engage the clutch to the sweet spot, it doesn't start, but once I pass that and the motor starts getting under its own power, thats when.

I just find it weird that it stops when the vehicle stops moving.

Is your alternator starting to go bad? Mine is and I get a whine from it. I thought my whine was a vacuum leak originally. I wasn't sure what it was until UNCC_99 heard my Jeep run and said it sounded just like his did before his alternator crapped.

I could be way off since mine whines at a stop and yours doesn't, but worth looking at to at least eliminate that as a possibility.

What year is yours?

So, it whines in gear under load or coast, but not when in neutral or the clutch is depressed? I have an auto, but have had sticks in the past. Sounds to me like gear noise from the transmission, or maybe the transfer case. Just my $0.02.

Can't believe I didn't give specs in the first post. Rusty.

'94, AX-5, 4.0L

I'll check the alternator, that's an idea.

Ugh, I hope it's not the tranny....

rocklandxjer said:

'94, AX-5, 4.0L

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An AX-5 mated to a 4.0L? Are you sure it's not an AX-15?

AX-5's are usually mounted to the smaller, 4-cyl. motor.

Also ... alternator noise shouldn't be affected by the clutch. It should match engine rpms, regardless of in gear or out of gear, clutch pressed or not pressed.

montanaman said:

Also ... alternator noise shouldn't be affected by the clutch. It should match engine rpms, regardless of in gear or out of gear, clutch pressed or not pressed.

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I agree with that, and my suggestion was more one of "here is something that could cause a whine, check it out and rule it out"

I'd place money on something else also, but best not to count anything out initially.

whoops! Wireless keyboard...sometimes the keys re finnicky. Yea, its a standard ax15/4.0

I'm not sure what this could be. It's not incredibly annoying and it isn't affecting performance in any way. I guess I'll just keep an eye (ear) on it and keep trying to rule things out

I had a whine that would come and go while driving - I got her her own car.

But seriously - I did not see that you said it went away when you depress the clutch while moving as one of the other responders assumed.

Does it or does it not go away when you depres the clutch?

Does it keep whining untill you stop regardless of clutch engagement?

Nope. It's not to do with the clutch as far as I can tell. I've pretty much conlcluded that the ONLY way to make the whine start is to give some gas. Once the motor torques up, it starts. It starts a bit above audiable, then dies a bit and levels off to just noticeable from inside. Then when I stop, it continues until the pile comes to a rest. Regardless of clutch engagement.

I feel like it could be a bearing/bushing/seal on the drive train.

I have this type of whine from my speed sensor.

Like, an actual sensor or the Speedo gear in the T-case?

Speedo gear in the T-case.