1991 Previa, 188,000 miles, original owner
My wife borrowed my van while I worked on her Subaru. The ingrate complained about the high-pitch whining from my car. Said it was so loud it gave her a headache.
The van emits a high pitch whining (screech) when I accelerate. The whining stops when I stop accelerating. The pitch and loudness increase with acceleration, and step down a notch when the transmission upshifts . No whining noticeable when idling in the driveway. I heard no whining when I supported the rear with jack stands and revved the engine up to 60mph (previa is rear-wheel drive). The whining has been occurring for at least 10,000 miles (2 years driving for me).
Yesterday, I replaced the two belts (pwr steering/alternator and air). No change in the noise. The pwr steering, alternator, and a/c compressor are original. Alternator seems to be performing it’s electrical functions.
The van is running fine otherwise. I’d like to eliminate the whine, but don’t want to shotgun parts, especially if there is a possibility this is incipient tranmission failure.
I don’t know this car but the belts are always a great bet. Are there only 2 belts? Is the tension correct?
I can only tell you that gutting my own car from the B-pillars back, lining the sheetmetal with structural dameping material, and overlaying that (and lining the cavities) with carpet padding, really made a huge difference in the level of road noise. I don’t know if it would help your siruation, but I offer the idea for thought. It’s simply a matter of getting the proper body manual and spending some quality time with the vehicle.
I’ve heard similar sounds on that model van before, and yes, it does sound like the transmission will eventually be taking a left turn on you. However, if you keep up with the services, you can still put another 100K or more on it. If you have the 4WD version, it could be (just) the transfer case input shaft spinning, so you could ignore it forever.
Whatever the final diagnosis, good luck…
I owned one of these for years. ( great van just odd ) I remember the early ones ( yours ) having a sort of whine whistle problem that owners figured out was a small hole in the exhaust somewhere. I am thinking it was the muffler. I hope I am remembering this correctly. If I were you I would check around on the net for Previa exhaust whistle as I am sure the old posts are still out there.
Thanks, all! (I was expecting a notice when people replied, but didn’t receive one…)
waterboy: Not sure the tension is right. I tightened to about a 1/4" deflection in the middle of belts with pressure. There are only 2 belts. I tried to find a tension gauge at the local parts stores, but they told me the stores haven’t carried them for years.
the same mountainbike: the van has always been noisy, but this is a new, much louder noise.
chaissos: it’s 2WD. I flush the AT myself, but haven’t made any adjustments (bands, etc)
kinsha: I’ll check it out.