Accidental Downshift at WOT

[Syffe]

I know.. I know.. I goofed. I was on the highway doing a 2nd > 3rd > 4th pull in my 2017 civic si. I was about 6000rpm in 4th gear when I wanted to go to 5th but shifted into 3rd. After I released the clutch I realized what happened. I like to think I pressed the clutch down pretty quickly. The noise the car makes when you bounce off the rev limiter, happened like 3-4 times before I pressed the clutch. I saw I revved up to roughly 8000rpm in 3rd gear. Tires didn't lock up, nothing snapped, and it felt as if I almost shifted into neutral. Its really cold where I'm at and I'm probably just paranoid. This happened over a month ago and over 1500 miles ago. The car runs and drives like normal, but well after my engine warms up, I still see a great deal of "smoke/steam" coming from the exhaust. Even after a 30 minute trip. The temps here are roughly 25-35 degrees F. I plan on making sure once it warms up to see if there's still smoke. I guess what I'm trying to ask is, did I screw up my car? How badly can I damage my engine, cylinders, head gasket, block etc. I'm not the most car mechanics savvy but any help would be appreciated.

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[TimberWolf]

Yeah, you can damage the engine internals badly by doing that. Mostly by hitting the pistons into the valves (valve float). Hopefully nothing actually happened.

If my calculations are correct, you would have hit 8000 rpm when you shifted into 3rd. That's not horrendous, especially if it only lasted for a fraction of a second, but I certainly wouldn't want to do it again. There isn't much you can do about it right now. If the car runs ok, count yourself lucky. If it smokes or runs poorly, you might be looking at a big repair build. I know that some cars will record max rpm, so if you take it to the dealer for warranty repair, they can see what the max rpm you hit and will probably deny warranty repair.

 

[Green82]

The smoke your seeing is steam from the exhaust because of the cold temps

 

[latole]

Firs you must learn the basic how to drive a car ; " I was about 6000rpm in 4th gear "

Or you have lots of money......

 

[dallasjhawk]

I know.. I know.. I goofed. I was on the highway doing a 2nd > 3rd > 4th pull in my 2017 civic si. I was about 6000rpm in 4th gear when I wanted to go to 5th but shifted into 3rd. After I released the clutch I realized what happened. I like to think I pressed the clutch down pretty quickly. The noise the car makes when you bounce off the rev limiter, happened like 3-4 times before I pressed the clutch. I saw I revved up to roughly 8000rpm in 3rd gear. Tires didn't lock up, nothing snapped, and it felt as if I almost shifted into neutral. Its really cold where I'm at and I'm probably just paranoid. This happened over a month ago and over 1500 miles ago. The car runs and drives like normal, but well after my engine warms up, I still see a great deal of "smoke/steam" coming from the exhaust. Even after a 30 minute trip. The temps here are roughly 25-35 degrees F. I plan on making sure once it warms up to see if there's still smoke. I guess what I'm trying to ask is, did I screw up my car? How badly can I damage my engine, cylinders, head gasket, block etc. I'm not the most car mechanics savvy but any help would be appreciated.

You might have an over rev code stored on your ECU now too. Hopefully you caught it quick enough that you didnt do any damage, but mechanical over rev is really bad for the engine internals.

 

[NoKz]

I would have someone check the valve train if possible. The over-rev could easily put it out of tolerance and they may need an adjustment. If the smoke coming out is there when it's not cold, it's possible a valve isn't sealing properly. The issue can vary from loose lifters to a bent valve as I doubt you have a damaged piston ring. I don't think you revved high enough to cause serious damage. But I think it's high enough to where the valvetrain may be affected as its usually the first to go in this situation.

I'm sure there's going to be additional wear on the bearings as well. But you can't really do anything about that without pulling the motor.

I'll also add that I think you'll be fine, but may want to have someone give it a once over just to see if anything looks out of the ordinary.

You might have an over rev code stored on your ECU now too.

Absolutely this.

 

[360glitch]

8000 RPM is *probably* ok. Not much you can do about it at this point. If it seems like it's running fine, continue on.

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