free revving on park/neutral

[Nissan101]

So i got my injectors professionally clean, in the cleaning process at random times the guy revved my engine to about 5000rpm for a few seconds

i used to free revved also before
Its only now im asking if its bad to free rev.....thanks

 

[KGMtech]

No damage done. Relax.

 

[ShotGun429]

not a issue.

 

[Leo99]

It's bad to do on a regular basis. It's ok to do if your diagnosing or doing a repair like this.

 

[BrocLuno]

Depends on the tranny ...

Old Chrysler 727 TorqFlite, you could free rev to 4K and drop into gear and launch if you were drag racing. They called that a neutral start. Not many others could tolerate even one of those

I prolly would not do it more often than necessary ... Al lot depends on if your tranny internals use bushings or bearings on the shafts and drums. And how well inherently balanced things are ...

 

[4WD]

BL: same when I pulled stuck vehicles (worst case) with my old PowerWagon - reckon they called it a 727 LoadFlight in the Dodge trucks ... that and the Dana kit it fed was solid.

 

[Lolvoguy]

An Italian tune up seems comparable with similar results.
Also a lot more fun

 

[crazyoildude]

Its never a good thing to rev an engine with no load...

 

[4WD]

It's never a good thing to have a new pickup stuck at 3 mile inlet with the tide coming in ...

 

[supton]

Originally Posted By: crazyoildude
Its never a good thing to rev an engine with no load...


Why is that? Not enough cylinder pressure to properly seal rings, not enough heat generated to... do something?

I can't see it being worse than idling.

 

[mjoekingz28]

Its like throwing a tennis ball instead of a baseball. I used to do this in my younger days. I would throw the tennis ball as hard as I threw baseballs and kept having pains and arm issues.

 

[CT8]

Why would you think it is bad?

 

[mjoekingz28]

Originally Posted By: CT8
Why would you think it is bad?




Go fer it! The higher rpm the better! Just make sure the engine is stone cold in the middle of winter so no damage occurs!

 

[demarpaint]

Originally Posted By: crazyoildude
Its never a good thing to rev an engine with no load...


It's even worse to rev a cold engine with no load.

 

[Nissan101]

The engine was fully warmed up
and he was throttling the car for some reason with the injector cleaning kit attached.
But as said before he carried the rpm up to about 5000rpm for a second or less

 

[KrisZ]

Let's hear some technical reasons why it's "never" a good idea to rev the engine without load, and no made up, feel good nonsense please.

I can think of few undesirable effects such an event can produce, but nothing that would warrant a "never" advice.

 

[bdcardinal]

If revving an engine in neutral without load was really bad then every Mustang GT and Camaro SS in the world would have constant blown engines.

 

[mjoekingz28]

It doesnt have to 'blow' the engine bcardinal for it to be detrimental.

Also, some mfgs put a neutral/park rev limiter on their cars.

 

[demarpaint]

A one time event isn't going to ruin an engine, I think most people here are in agreement with that. People who make a steady diet of doing it can have problems down the road. I have a neighbor who does it as some kind of ritualistic behavior when she starts or shuts her car off. I've noticed over the years typically by the end of her lease the car is blowing blue smoke. It's a habit I'd certainly avoid. If I had to wager, I'd say its worse when the engine is cold or first started.

 

[bdcardinal]

There were some transmissions where you couldn't rev an engine in park/neutral or it would cause damage. It is in the smog check guide for California. The vehicles are known and the smog machine automatically skips the 2500RPM part of the TSI test.