Patsum

I have a 1998 ls with 122K on it

she is making a bit of a whining noise I am trying ti diagnose.

The noise is a constant low noise I can hear in the cabin and outside the car.

The noise happens when I either turn the a/c compressor on
or turn the headlights on
or turn the steering wheel while stopped using the PS pump

It will dip the rpms bb 100-150 RPM of normal idle and then I get this noise.. sounds like it is straining a little. I know the rpm's should CLIMB when I turn on things like the a/c or power steering use.

a/c off but the headlights on = noise
a/c and headlights on = noise
a/c on and ps pump use = noise
a/c off and ps pump use = noise
a/c off and headlight high AND low on = noise

what the heck could this be? I think the P/S pump and a/c comp and alternator are all run off the same belt. Could this possibly have to do with that? seems like whenever I am loading the accessory belt down I get this noise . That is, assuming they all run off the same belt.

I tried to take a video of the noise. you do have to turn your volume up and I am so sorry my voice is so loud. Just listen and see if you can hear.


I don't want to just throw money at it or pay $100 for a diagnosis...if I can help it.

with my stereo off and the windows up I can certainly hear this without trying at all. It's not just a regular thing as my 1991 LS400 never did this.

rogzballz

iTrader: (9)

Your alternator clutch has gone bad. Happened to me because I replaced AC compressor, tensioner and belts with the same sound and shaking.

Patsum

Alternator clutch? Hmm never even thought about that! It just confused the hell out of me with the symptoms not all matching any specific part. alt/ a/c / power steering units all affecting the noise and shake.

Thanks!
Think I can have the clutch replaced by itself without the entire alternator? or is this a buy a new alternator and suck it up kinda deal?
Pretty much trying to see what to tell my mechanic to do to keep this as cheap as possible while fixing the issue.

Patsum

my mechanic informed me by showing me that my alternator has no clutch of any sorts. Any other ideas?

PureDrifter

iTrader: (10)

alternators don't have clutches lol.

I suspect the headlight involvement is transitory in nature and due to a minor issue with the vehicle's electrical system. When working properly, having the headlights and taillights on will not cause any noticeable change in engine RPM. the fact that yours changes, even slightly, indicates the system is loading high, due to an alternator issue, dying battery, or bad/dirty ground (or any combination of these).

The actual source of your problem lies with the AC and idle control. The AC compressor and clutch should be checked for any unusual noise and proper clutch function, and to ensure the system is properly charged with refrigerant. if it works fine and and checks out fine, you should pull the throttle body of the car and properly clean it (be careful with the electronics), paying special attention to the idle ports as they get gunked up.

Your car is idling somewhat high. With no load and in neutral it should be around ~600RPM, +/- 50. Yours was at around 800+ from what I saw.

Patsum

PureDrifter

I will check out the alternator and battery both today!
I will also check to make sure I have enough refrigerant, I may be a little low...

I also just had the throttle body cleaned out with new gasket. No difference.

Shouldn't the idle go UP when I turn the a/c on? not down?

I will adjust the TPS today for a 600-650 RPM idle speed as it is a high idle.

WIll report back after I do all this.

billydpowe

iTrader: (1)

While you are doing the water pump and timing belt and all the bearings, just put a new drive belt on and it might all go away...

PureDrifter

iTrader: (10)

unless you have a service manual don't touch the TPS, the way the '98-00 manage idle control is very different from earlier models because it's a DBW system.

Yamae

I don't know my problem was related to yours but let me write what I had experienced last summer. The noise you are having sounds like a bearing noise to me but my noise a year ago was different. It was like a whistle but it varied a lot. sometimes none, sometimes high pitched or low pitched depending on the temperature under the food. So my experience might not be related to yours directly.

When I had a cracked hose below right side on my 98 Celsior 145,000km, I had some unusual noise and a high idle rpm with a strange idle up or even sometimes down turning the AC on.


Depending on the temperature, both the noise and the rpm have changed some. The hose was used between the PCV valve and the throttle body and it was absorbing the air. The crack was at the lower side of the hose and you could not notice it easily. The amount of absorbed air was varied depending on the temperature of the hose since the temperature affected the stiffness of the hose and this varied the gap of it.

Since the absorbed air was giving the engine some extra amount of air and the idle control function of the ECU was not properly done. This may be the reason why the idle up was not done well when the AC was turned on. The problem was completely fixed after changing the hose new shown left side.

It has been nearly a year since I had changed the hose, the grommet of the PCV valve and the transmission mount . Last summer I had been wondering why the idle was not stable and what was the noise source. I also had some unusual vibration running at highways. All the problems had gone and this summer, my Celsior is running like a new. Aged rubbers are what you have to pay attentions on your car, I understand.

rogzballz

iTrader: (9)

Yeah they do! But maybe not for his car....

http://www.qualitypowerauto.com/catalog.php?item=168

http://www.lexussouthatlantaparts.co...74150W130.html

PureDrifter

iTrader: (10)

a one-way decoupler is not the same style traditional clutch that's found in AC compressors, nor are cars made 5 years later, fwd, with V6 engines relevant in this case.

mikes7ke

iTrader: (1)

I never knew the temperature under the food was so important.