Is Revving ok?

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I was bored in the parking lot today and decided to rev my engine in park a few times, but I was told that it could be bad for the engine, is that true? (It's an Automatic 1998 Nissan Altima GXE), and I didn't think it would hurt anything, but I wouldn't know...

posted by  ThirdeYe

It's not that bad, but it's not good either. Just don't do it. if you're that bored, read your car manual or something.

posted by  Godlaus

man... how do u find reving ur engine fun? might as well make fart noises with ur armpits.

posted by  Ki2AY

Ha, I didn't think it was fun, I just did it to scare someone that was walking by.

posted by  ThirdeYe

might wanna rethink the trade, new engine for the amusement of one scared kid.

posted by  monteofdoom

I believe it is harmful to your engine if you rev it high. Many cars have governors to limit the RPMs to about 4k. When you rev, the engine doesn't get the same lubrication that it would if you were driving because it is a sudden increase. The oil doesn't get to all the internal moving parts as in a gradual climb in RPMs as seen in normal driving.

posted by  968racer

which makes me think... how far did you rev it up to and for how long? i dont think its harmfull at all unless you kept it redline for awhile ...

posted by  Ki2AY

There's no inherent harm in revving an engine, so long as you don't exceed the redline and don't have it up there for too long. Yeah, oil circulation becomes an issue, but not on a little throttle blip. That's really only if it's at high revs for an extended period of time.

968Racer, all modern cars have rev limiters (so you can't grenade your engine by being careless) but the actual limit depends on the exact engine. An LS1 might cap out at 6000 for example, while the Honda 4 bangers are typically 8000-9000 (or more).

posted by  Martian

it didn't redline, and I just basically pushed the pedal down to make it loud enough, then let go.

posted by  ThirdeYe

revving it and then letting your foot off straight away wont do much damage to the engine if you do it every so often, but it is a bit childish (I'm 14 and i dont do it anymore!)

posted by  D4NDO

Interesting... these are the facts they don't quite mention in the manual. I got one, probably bad, but I'm curious of how bad it is. Is it bad if I'm at a red light and let go of the break and hit it again so my car shakes forward and back then repeat it, so it mimics hydraulics?

Lol
Lee Pham

posted by  leepham

what are rev limiters and governors for? Can you take them off?

posted by  CarEXPERT

if you read the posts before this then you would see that they are to stop you 'grenading' (blowing) your engine and yes you can but it would probably do more harm than good.

posted by  D4NDO

In my dads car when I drive it, I can go all the way to redline and it shifts. Is the limiter for making you not go PAST redline?

posted by  CarEXPERT

depends on manufacturer and what they set it at

posted by  carlos

Martian, yes almost all cars have rev limiters that limit the RPMs while in gear. Many of todays cars also limit the RPMs when there is no load on the engine (ie in neutral). Many are in the 4000 RPM range even though the redline can be at 6,500 or higher.

posted by  968racer

revving the engine doesnt do much damage in park. like everyone said theres a difference between revving it and holding it at 7000 rpms while in park. revving consists mostly of giving it gas and letting it wind up and shake the car, (or if your in a honda just making a louder farting noise than it was at idle) and then letting off the gas. but holding the gas down while in park and letting it rev continuously at any rpm above 4000 for more than id say about 5-10 secconds is just plain stupid and can do some slight damage. but i dont know why youd be reving up an altima 4 banger to begin with but what you did didnt do any damage. i probably do it more than anyone here. but then again when i rev my car it gets heard. and you dont hear burrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrr. but other than that the only bad thing about it is its a waste of gas in my car. (not so much in a little 4 banger) but still its more mature not to do it. but dont let a farse about it hurting your engine stop you. let your maturity stop you

posted by  72firebird

Revving your engine absolutely IS damaging it, just not catastrophically. Not immediately, anyway. Just by punching the throttle once or twice, regardless of whether it hits the redline or not, and especially when the engine is cold or you're just turning it over, you are causing irreparable damage to the cylinder walls, the piston heads, the piston rings, the piston seals, the valves, valve seats, seals, heads, block...etc. Additionally, you are dumping excessive amounts of gasoline into the engine that cannot burn off (larger drops of unaspirated fuel do not burn as well). When this happens, the excess fuel will drain down to the oil pan and mix with the oil, reducing it's viscosity and making it an ineffective lubricant, which will lead to more friction, to more heat, and eventually engine failure due to excessive wear.
Some of that excess fuel will be blown out with the exhaust, will create a large build up of carbon on your valves making the engine not able to "breath" correctly and will result in excessive fuel consumption. The fuel that makes it through the exhaust valve and out the manifold will burn off in either your catalytic converter or your muffler. Best case senario it produces a lot of carbon and obliterates your fuel economy, eventually causing the engine to run for a few seconds, suffocate, backfire and die. Worst case creates excessive heat and fire.
The biggest issue with revving your engine isn't the long term effects it WILL and DOES have on your engine, it's the damage you are causing your transmission. See, your transmission is bolted directly to the flywheel of your engine. As long as your engine is running, your transmission is moving too, even when in neutral. There are a lot more moving parts inside a transmission, which means a lot more friction and a lot more damage potential. Revving your engine is also revving your tranny, and heat build up will eventually lead to replacing one or the other, or both.

There is NEVER any need to rev your engine unless you're working on/tuning certain engine components.

An Actual Mechanic   14 Jul 2012 22:59

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