How high is it safe to rev your car engine when at idle? RPM?

As long as your not red lining it you will be OK, I don't know what year your trans am is but the newer ones have a built in rev limiter built into the computer so it will only rev so high in park or neutral before it cuts the engine out so it doesn't do damage.

Rev it as high as you like - but only up to the redline. Never past it.

Most GM stuff built after 1995 has at least 1 rev limiter, some have 2.

A rev limiter stops the engine from revving past a pre-set RPM. It doesn't hurt the engine to "bounce it" off the rev limiter. Rev limiters may work in several ways. Some cut off the fuel, some cut off the spark plugs, some do both. Some, on cars with electronic - i.e. no physical connection between your accelerator pedal and the actual throttle - may actually take control of the throttle and close it.

Basically, if you have a rev limiter, you can put your foot to the floor, and the engine will not rev past it's preset limits (as long as the rev limiter, engine computer, sensors... etc. are all working as they should).

The most common rev limiter is set just at, or just past redline. This rev limiter keeps people who are foolish and/or not paying attention from blowing their motor (hopefully).

The second one is set lower, usually around the 4000 RPM mark. This second one is speed sensitive on my GM car.

I have a GM 5 speed, and if I'm completely stopped in neutral (or any gear), and I accidentally rest my foot on the gas or something like that, it will only rev to 4000 RPMs. If I get the car rolling, even 2-3 miles per hour, I can rev it to redline.

Since you mentioned "park" in your question, you probably have an automatic. And unless it's a really old trans am - it should have a rev limiter.

And I agree... it's fun to rev it. Especially a nicely tuned V8. It sounds good - like a symphony... have fun.

Just don't do it in front of a cop. At the very least, he'll tail you.

At worst - you will get a B.S. ticket for some trumped up charge.

Have fun.

Rev away!!!

Revving the engine does no harm.

NOW... if you rev it up, and then drop it into Drive or let the clutch out very quickly... that can possibly cause harm. Usually, transmissions, clutches, drive axles...etc (all together called the drivetrain) can handle a "hard launch". But if you do it over and over and over, you'll either brake something expensive, or at least put excessive wear and tear on the engine and drivetrain.

So, again, unless it's very old, you probably have a rev limiter.

Either way - young or old - revving it short of redline should.... do no harm.

"a trans am is a sports car if you did not know that and revving helps clear the exhaust system for performance"

And who fed you that line of bullshit? It doesn't do ANYTHING of the sort.

Whether it's a Trans Am or not, you still look like a complete retard just reving the engine. And I drive a 1970 Mustang, before you decide I'm just another "minivan" driver.

Clear the exhaust of WHAT? - exhaust gas??? - carbon build up???

You cannot even measure the difference between a so called dirty exhaust and a new one - so how on earth can revving the engine up improve performance???

Someone is filling your head with rubbish.

Do you see REAL sports car drivers rev engines up to clear the exhaust??? And I am not talking about your average red neck at the race track on weekends - look at the PRO's.

First of all, locate, remove, and clean your IDLE AIR CONTROL VALVE. I always recommend using Amsoil Foaming Cleaner and Gum-out for this job. You can run these chemicals through a running engine and remove unwanted deposits from O2 sensors and converters. You're on the right track by cleaning your throttle body, just go a little bit deeper. You can reset the computers on most Nissan products by turning the key on and off 5-6 times, waiting 5 seconds in between. Good luck!!

nascar uses carbed engines making 800+ HP at 9000 RPM's. Those engines have virtually no vacuum at idle and are tuned to run above 5 grand. They don't idle on their own for long. Thats why they rev them. Your car has no comparison to that.

Newer cars you can put it to the floor. The vehicle has a limiter that will only let it rev so high and will go up and down while on the floor!

2-3k is fine while sitting still!

as high as you like however, do not go over 5,000 when in gear or you will blow your tranny, revving your engine, DOES NOT CLEAR YOUR EXHAUST PERIOD. however you could wind up forcing an objext that was stuck inside right into your catalytic converter and render that useless.

There's absolutely ZERO point in doing so.

But 2k rpm won't hurt anything.

Just make you look like an idiot, as you sit there and make your engine sound obnoxious.

Think of it this way.

You could ask "how loud can I talk, without hurting anything?"

Point is, you can talk pretty loud, if you want. But no one else will appreciate it. Just get annoyed.

revving the engine won't do any harm...but for what purpose would you need or want to?