I have a bone stock '96 4L auto. On an almost daily basis I push it up to pretty high rpm's. I had it at 5500 rpm's a few times, is this bad? rpm meter goes to 6000rpm with no red lines.

 

this is a huge controversial topic.

Your vehicle does have a redline...its called the rev-limiter. You cannot bypass it without a tune. I say NO this isnt bad. I regularly push my 2000 3.0 to 4700-5000 out of 6000 daily with gear drops and so forth.

Heres my reasoning. I know idling is not so good for your vehicle. Neither is engine revolutions past 6000. From prior knowledge of general engine mechanics on go karts and other trucks however I know that my 3.0 has more power and can do more than what my truck lets me (this is true of any engine) but they limit it for your safety. But I know my truck cannot do less than 0rpms (obviously). So I would say the upper end of your rpms is about the middle range of what the engine can handle. I wouldn't recommend running your truck without proper maintenance at these rigorous levels but yes you can run your truck at the upper spectrum of power regularly without ill effects.

others will say otherwise.

Just be safe. use the right gears. Use the right fuel. use the right oil. Feed your engine lots of air and yes you will be fine.

 

Well I meant their is no literal redline where the rpm's obviously shouldn't go. But thanks for the information, that's good to know.

 

Unless you get your engine past the mid way point once and a while you aren''t breaking any carbon loose and heating those pistons and valves up all the way. I do a pull to at least 4.5k once a ride.