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2000, 2.5RS, STM
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163 Posts
Discussion Starter · #1 · (Edited)
So I want to know what sort of damage may have been caused by an inadvertent down shift.

I was heading home from the mountains the other day when I came upon a slow group of cars that were stuck behind a huge boat. After I could take it no longer I decided to pass the group. No problem, I shift into third, pull into the oncoming lane and floor it. As I reach my shift point in third (somewhere between 5-6k I think) I try to slam it into fourth as I pass the slow boat hauler--but disaster, oops, I shift into second.

Now I only released for the briefest of seconds, there was a clunk with clutch engagement (not sure if it was from the clutch or normal rear dif clunk) and the care roared loudly as I saw the dial almost instantly reach towards red line. I don't think It went beyond red line, I put the clutch back in immediately, but it certainly engaged somewhat. I was paranoid over every sound from the car the rest of the way home, but really it made the rest of the 200 miles home without any mechanical quirks.

My question: could I have done something bad despite it running alright? Should I check something or change fluids or something?

CN:
1. Stupidly tried to pass lots of cars
2. Down shifted into second instead of going up to fourth
3. Am I screwed?
 

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James incognito
Black 06 STi & 07 Wagon
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324 Posts
I've done that in the past. It's really not a big deal. Most cars can occasionally run at redline for a few minutes before they blow up. A second or two? They're built to handle that!
 

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Banned
'04 RS PBP w/ Black Tarmacs
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1,805 Posts
Our cars have built in rev-limiters. I've bounced off mine a few times already. I think the only way you can do engine damage by over revving is by putting the car in too low a gear at high speed and allowing the gearing to force the engine past redline. This would possibly cause valve float and/or bend connecting rod(s).
 

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00 2.5RS BRP
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687 Posts
don't sweat it....have you seen what honda kids do to their cars? A Subaru motor can take it for a little.
 

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95 GC 371hp/355tq ej25 1.5xtr
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4,494 Posts
Our cars have built in rev-limiters. I've bounced off mine a few times already. I think the only way you can do engine damage by over revving is by putting the car in too low a gear at high speed and allowing the gearing to force the engine past redline. This would possibly cause valve float and/or bend connecting rod(s).
yea your right, our cars have an electronic rev-limiter, the ECU cant control if we dont shift by accident and lets say the rpms jump to 7k. the car doesnt have a limiter MECHANICALLY, the ECU helps limit it by cutting off fuel and shit like that.

oh... and dont bounce of the rev limiter
 

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98 2.5RS ~ EJ257D Hybrid
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864 Posts
they call that a money shift, buddy of mine did that in his 04 bmw 330, had to rebuild the heads, wern't priddy
 

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2000, 2.5RS, STM
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Discussion Starter · #8 ·
they call that a money shift, buddy of mine did that in his 04 bmw 330, had to rebuild the heads, wern't priddy
This is the sort of thing I'm worried about. The potential damage to my transmission/ clutch is the most obvious. Now there isn't much I could do in either case; save perhaps changing the trans fluid.

The less obvious damage is concerning, I just did a HG rebuild about 3 months and 5000 miles ago; could I have f*ed up my HG again. What other engine internals might be prone to damage from brief excessive RPM. Could I have hurt the timing belt or anything?

Thanks for the input, the car does run like it did before, I'm just paranoid.
 

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2000 2.5 RS Impreza 4 door
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So you accidently put it in 2nd gear when going like 50 or 55 or higher? I wouldnt be confident in saying nothing is wrong but Im no professional.
 

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James incognito
Black 06 STi & 07 Wagon
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324 Posts
This is the sort of thing I'm worried about. The potential damage to my transmission/ clutch is the most obvious. Now there isn't much I could do in either case; save perhaps changing the trans fluid.
Uhh... you can't screw up the transmission by over-revving the engine...

The less obvious damage is concerning, I just did a HG rebuild about 3 months and 5000 miles ago; could I have f*ed up my HG again.
Your headgasket is more likely going to be damaged by an overheated engine, not revving too high...

What other engine internals might be prone to damage from brief excessive RPM. Could I have hurt the timing belt or anything?
Whoa, you need to calm down. About the worst you could have done would be to float the valves and hit them, which could damage a valve or bend a rod. Now, if that was the case, you'd KNOW. You car would not be running.

Thanks for the input, the car does run like it did before, I'm just paranoid.
Yeah, you're WAY paranoid here. Have you ever seen someone TRY to kill an engine? It's pretty hard. Engines are pretty tough.
 

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Discussion Starter · #12 ·
So you accidently put it in 2nd gear when going like 50 or 55 or higher? I wouldnt be confident in saying nothing is wrong but Im no professional.
Yea that sounds about right, I was accelerating from 50-60mph when it happened. So that means in essence that I engaged second gear at that speed.

How brief, and how excessive of an RPM?
I let out the clutch, heard a clunk, and the engine roared up RPMs; as soon as i noticed I put the clutch back in. All told it was only engaged for a split second; but it did rev the engine very high and loudly.

So it sounds like if I had floated the valves I'd know it.
 

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sold it to Susie the Subie
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3,233 Posts
going by the deatils provided, you are fine. I've done it before too, no biggie. If you
dind't go over redline think of it as just driving like a person who likes to redline. If you
went over it a little, not biggie. They wouldn't make the 'destroy my car zone' reachable
like that. There is some buffer between your redline and where you don't want to be.
Your car would have jerked crazy too if you got to that point to slow itself down.
Don't worry about it. Nothing is wrong with your car.
 

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Meany Head
2000 RSC
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10,236 Posts
I re-iterate my original post. I doubt you have anything to worry about. The stock EJ251 can handle spinning up a few RPMs past redline without any damage. You'd have to have really let it spin high for more than a faction of a second to pop a valve or something.
 

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sold it to Susie the Subie
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+1 at what the Honda kids do to their cars too, lol
 

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'98 RS, '13 BRZ
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689 Posts
yeah, if you never went over red-line, or een if you did a little, your fine. Just try not to make a habit out of it. I've caught myself a few times accidentally letting it rev to over 7k, which i didnt even think possible with the rev limiter, and my engine was fine.
 

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2005 Subaru Impreza RS 5MT
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Yea that sounds about right, I was accelerating from 50-60mph when it happened. So that means in essence that I engaged second gear at that speed.
50-60 mph and 5-6k rpm don't really line up...6 thousand rpm should put you at almost 80 mph in third gear. Second gear is good for something like 55 mph at redline.
 

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2005 Baja Turbo
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1,448 Posts
Duuuuude... Subies are good up to about 8,000-8,500 rpm. I dumped a 1995 BK (SOHC 2.2) into second on the freeway, revved the piss out of the motor, and it was fine for a long time after that. In fact, I frequently put that car into too low of a gear at too high of a speed, running way too many rpm, and only after doing that a bunch of times, did a valve bend. Doing it once and not letting it rev for 20 seconds while you decelerate isn't going to hurt anything.
 

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98 rswrx
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27 Posts
ive seen lot porters at my work downshift a mini cooper s from 5th to 2nd accidently, over reved the turd and nothing happened, as long as u dont hold it there forever ur good to go. no worries. if by now nothing is wrong then i highly doubt u did any damage.
 
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