frankheat

Hey All,

Recently purchased a LS400–engine felt and sounded good. Recently took it for a standard tuneup(spark plugs, filters).

I didn’t realized it at first but when I got the car back the engine has been making a whining noise. It follows the RPM and is loudest while idling in park. It isn’t more distinct in any gear and the pitch follows acceleration. I also detect a slight crunching sound when shifting to reverse but it’s hard to hear over the sound of automatic side view mirrors lowering. The AC has an effect on the whining where it momentarily causes it to change pitch. Turning the steering wheel has no effect on the whining noise.

I’m kinda in the middle of nowhere right now with limited options for mechanics. The guy seemed ok but it was definitely a hole-in-the-wall type of place.

Does this sound like incorrect tranny fluid? It seems strange that it would happen right after a supposed tune-up. I could find fragments of similar problems in other postings but couldn’t find identical symptoms. Any help is appreciated.

Thanks,
Frank

RA40

iTrader: (6)

Did they change the transmission fluid? When was the timing belt service? Check the engine oil level since you are in there as well as the power steering fluid. Does this whining come through the radio or is it a mechanical engine bay noise? The suspects that come to mind: power steering pump, A/C compressor, serpentine idler pulley and alternator.

frankheat

Thanks for responding. Not sure about the timing belt. All the levels are ok. It is coming from the engine bay. The mechanic says he didn’t mess with any of the fluids so I guess it’s not a case of incorrect type.

It was just curious to me that it started after being serviced. Do noises from power steering issues correspond with rpm? Because it changes pitch with acceleration. Also the sound it makes when put in reverse.

Thanks again for responding—I haven’t owned a car in 10 years and even then I didn’t know much.

400fanboy

Poke around under the hood to see if you can hear a specific area it's coming from. Or, better yet, record a video or something with sound and post it so we can hear as well.

Though do have one question - does the noise change at all when the car is cold vs. operating temperature?

And anything that's belt driven could make noise that's tied to the RPM. The accessories are all belt driven so the pullies are all linked to engine RPM.

FloridaCam

You can isolate isolation the problem with power steering or AC by removing the serpentine belt. Let it runs for under 30 seconds and listen if the noise is still there. If it is, then it has nothing to do with Powersteering or AC or anything connected to the serpentine belt.