what's that Whining noise?!? fan clutch? water pump? that area...

Today my 88 MJ 4.0 started to make this whining sound, I popped the hood and listened and it sounds like it is coming from somewhere around the fan clutch/water pump area, but I can't tell for sure. It starts and stops occasionally also, with no reason that I can find...

Do any items under there make a noise like that when they are worn out?

thanks
brett

A whining noise could originate from any one of those things, power steering pump, alternator, water pump (not so likely), also check the idler pulley bearing on the belt tensioner. This kind of noise can be hard to pin down, especially if its intermittent. A stethoscope can be really helpful here!

I had a similar problem about a year ago. I ended up taking a nice solid crow bar and by resting it on different parts and then feeling/hearing the vibration. It worked really well, the problem ended being my alternator. If you do this, watch out for the fan/belt.

My 87 XJ is whining right now, really loud, little STP belt dressing and it stops.

I've had this happen many times on many Jeeps, solution has always been for me...replace the serpentine belt, that is IF the noise goes away w/ belt dressing.
I figured loosen the tension on the belt, nope, new belt always solves it.

The belt I have isn't awful; it's got some cracks here and there. Many might scream FOUL, but I ONLY buy the $30 Goodyear Gatorback belts now, they're twice as much, but they don't make noise a few months later like the half as much Kelly Springfield's(which goodyear makes).

If you try the belt dressing and it doesn't go away...then you've got a component issue, pump, alternator, or you've got a bearing or several in a pulley misbehaving. The A/C pulley, whether you have A/C or not tends to make some racket, in my experience.

As far as finding noises, go to a local harbor freight store, or online, they have an auto stethoscope for under $3.00, it has a long metal rod and I find I use it often now.
Just don't put it on and walk around with it on...it's loud.

Good luck!

Teron

make sure tha the pulley on the water pump is not wobbly.... we had a guy on a trail in Moab who had some whining which got louder and louder and louder and then it resulted in the water pump going "pooof" (thankfully we had him off the trail by then)

Kejtar