Whine or whistle in engine bay under hard acceleration

Asking for help to find / fix a high pitched whine or whistle in my engine bay. I can reliably get the noise at 1/2 - 3/4 throttle if over 2500 RPM and accelerating.

This has been going on for a while now. It is not real loud - matter of fact if the radio is on you can't hear it much at all.

I am thinking it might be transmission - not gear noise but some kind of servo noise - as I can on ly get the noise under load. THat is, in Park if I move the throttle around I can not reproduce the noise. And it is easier to get the noise running uphill.

Any ideas?

abertj

you don't have a supercharged 3800 do you? it is a known issue with them.

Mine started doing this at around 110k miles, sounds louder driving in lower gears. At 138k miles, I wrote INTENSE Racing about the problem; they gave this reply:

"Usually when clutches are worn the pump will whine because the pcm commands the pcs to give more pressure to stop the slipping. I'd say with that mileage you have it's time for a rebuild."

That was from July of this year. I've decided that if the transmission dies, I'll pay for rebuild or replacement. Otherwise, I'm going to live with it. It actually reminds me of a racing trans... kind of like it!

Hmmm.... I have abot 172,000 miles. Transmission was rebuilt once, at about 97,000 miles, to repair the overdrive TCC solenoid. It is warranted. I am supposed to take it back every 40K or so for a checkup... so it might be time, have to look at my notes. That said, when it is time for a check I will talk to that mechanic about the whine. [in the meantime, pass the cheese...]

And I do have a supercharged 3800. I have never touched the blower except to open the fill hole to change or top off the special oil. The blower has always gently whined under hard acceleration (kind of pleasingly, actually). This sound is more of a whistle.

I have Alex Peper's Car-Code diagnostic software for my laptop. If I connect Car-Code to the car (it will take a log of the sensors and comptuers) can I see if the PCS is being commanded to apply extra pressure?

Thanks

albertj

I was just kidding about it being the SC

It's been more than a *decade* and I finally found this whistle - in my case it was a small air leak at the supercharger-plenum gasket (not the LIM). Fixed Wednesday.

Jason wasn't kidding, although his guess wasn't provable without a lot of wrenching.

Albertj

You are a very patient man!!

jbird wrote:

You are a very patient man!!

I figured I'd say what I found. This is why this *site is so helpful...

[/quote] I figured I'd say what I found. This is why this *site is so helpful...[/quote]

I agree 100%
There has been threads that I have read pages & pages of dialogue & the thread stops without the final fix/resolution.
I was seriously impressed you finally got to fixing the issue after all this time.
Sharing your finding is a great thing, it may help someone else down the road.

Jbird

I didn't know it was an issue... I changed the manifold gaskets for maintenance because I had pulled the throttle body and found that gasket had failed. So I set aside time for the manifold gaskets, which are the other coolant related gaksets on the engine.