96 Monte Carlo Z34 RPM problems

[SleepyBrownReese]

my car is a 1996 Monte Carlo Z34...it is a 3.4 V6 DOHC, automatic(dk if they even made manuals for them)...my question is this...sometimes, when my car is in park or drive, the RPMs will be very high, as in around 3500 to 6500...it's not near the red line, but enough for me to be worried...I have to put the car in 1st to get the RPMs down, causing a slam in the gears when it drops back down to first...I know this can't be good for the car, but I have no idea what to do about it b/c I'm not car smart at all...if somebody knows anything about it, even in general, it'd help 2 let me know what I can do......thanks!

[maxwedge]

No check engine lites? Get this scanned or looked at by a competent mechanic,

[CEO Wrench]

Originally Posted by SleepyBrownReese

my car is a 1996 Monte Carlo Z34...it is a 3.4 V6 DOHC, automatic(dk if they even made manuals for them)...my question is this...sometimes, when my car is in park or drive, the RPMs will be very high, as in around 3500 to 6500...it's not near the red line, but enough for me to be worried...I have to put the car in 1st to get the RPMs down, causing a slam in the gears when it drops back down to first...I know this can't be good for the car, but I have no idea what to do about it b/c I'm not car smart at all...if somebody knows anything about it, even in general, it'd help 2 let me know what I can do......thanks!

It sounds like the idle air control motor, or it has a vacuum leak - this is usually the lower intake manifold gaskets, but it could be the brake booster hose, or other vacuum lines. Use a can of brake cleaner (with the straw in the nozzle) and spray small squirts with the engine running in the lower intake area or other areas you suspect there could be a leak. If there is no change in how the engine is running, that would rule out the lower intake gasket.
Don't slam the car into gear with an idle above 1,300; this will surely destroy the transmission.

[Ethan504]

my dad has a 96 Monte Carlo and it did the same thing, it kept dying and revinng up real hard when he was in park and then goin real low
it was the o2 sensor, had it replaced and has never done this since