bigbernie

Ok, here goes...

Yesterday I charged my a/c and now my 99 Cherokee Sport is making some noise.

But a couple of days before I ran the t-case through the motions.
I put it into 4Hi, low and shifted the tranny into R, N, D, 3, 2/1(same spot for 2 & 1) moving the jeep foreward and reverse in straight line no turns 30 - 50 ft just to check the ease of use. Following the owners manual for usage.

I had no problems though 'til yesterday.

What happens:
When I start the engine it rattles.
During idle it growls (sometimes)
When in R, N & D at any speed, but with engine at idle it growls.
Espesially when in R it gets louder.
And all this with a/c or no.
Oh, and the noise goes away when the rpms are above 1200.

Now what I'm asking is for some help in diagnosing the problem to the source and figuring out what I need to do to resolve the issue.

I can fix almost anything, but I'm not very good at diagnosing.

freegdr

what ,when and where needs to be added by you

bigbernie

I had to fix the post. I'm using a touch screen and I hit the send button by accedent. Sorry.

bigbernie

Any help at all?

If you've never gone too far, you'll never know how far you can go.

lolz_jeep

it could be your a/c compressor or viscous fan could be going out. when u say u charged your a/c do u mean u topped it off or filled from empty

lolz_jeep

well actually come to think of it, she also sounds like she might need a new torque converter

jth877

The AC clutch turns on and off every 10-15 seconds to circulate. I would turn the AC on and check to see that it is fully engaging and disengaging when it cycles.

If that is OK, I would go under the jeep and open the inspection cover for the trans. You'll see all of the torque converter bolts. See if they are loose and torque em down.

If that still isn't the cause you might want to get a mechanics stethoscope and track down the noise that way.

bigbernie

Ok, checked the clutch on a/c and no cycle, just stays on. It stoped cycling after I charged/topped it off.

Tell me more about the fan cause it stops making the loud noise when I turn the control to off...
8 position switch

Almost forgot the loud noise is only hearable from inside

jth877

Can you hear it more towards the passenger side? The blower motor is located on the passenger firewall. Can you get the sound with the AC off, but the fan is still on?

The AC clutch shouldn't stay on all the time. If you had a low enough charge it wouldn't turn on at all.

bigbernie

Yes the sound is comming more from the passenger side. But that is just loud noise.

However the low growl is still there. Do you think it could be both?

I don't want to spend a couple a hundred on the blower, just to have spend another $200 on a compressor too. Then find out I need tranny parts.

Can you tell me more about diagnosing the verious parts?

Amost forgot... The low growl starts to go away when I rev the engine up 1500 rpm

lolz_jeep

if ur a/c clutch stays engaged then thats a huge problem something a/c related its not building enough pressure is system that means your compressor is bad and that would cuase a low growl noise and its on your pasanger side. but yea it could just be your blower motor to. try running ur blower with key on engine off and see if noise is still heard if not its most likly the compressor

lolz_jeep

the only thing that worries me about this is you say it gets louder in REVERSE and that normally points to a torq converter

bigbernie

Ok, did thorough check out. Here are the results:

Let blower run 4 30 min (no engine), no sound.
Left blower off and drove jeep 4 30 min low growl is constant R-N-D-3-2/1 when rpm is riased.
Blower/heat/ac on, loud noise is there and noise gets worse in reverse.

Now what?

lolz_jeep

now that you've ruled out a/c components now its time to look at bigger items such as torque converter.

dose the noise start as soon as the vehicle is started or only when your moving

bigbernie

It gives a rattle at startup then noise stops. In idle low growl is there but bearly. And you cannot hear it from outside unless you pop the hood. Then only just bearly.

Inside the jeep you don't hear much until you put it in gear. Then it (low growl) gets louder when you rev the engine. Let off gas and it gets quieter. Press gas and growl gets louder to a point. But it still only sounds like it comes from under the hood.

And the loud noise that only occurs when the heat/ac is on is the noise that gets louder in reverse.

The low growl matches the rpm to a point then evens out at about 2000 rpm. Let off the gas and growl is gone instantly. Oh, and you still can't hear the growl from outside even when moving.

How can the loud noise and the tranny be connected? I can understand the growl, but still?