Hi all,

Yesterday I was doing some spirited driving on a local mountain road in my AP2 when I hit a pretty long straightaway. I decided to go WOT, shifting near the redline of 8000rpm. As I was shifting from 3rd to 4th, I think I may have accidentally downshifted into 2nd, but I'm not 100% sure whether I went into 2nd or 4th. I definitely have accidentally shifted from 3rd to 2nd before, but never at 7k+ rpm. The engine immediately stalled, all the dash lights turned off, and if I recall correctly, the shifter never fully entered 2nd/4th before popping back into neutral (my memory is hazy on this part). My friend who was following me said he saw my rear tires lose traction when this happened. I braked to a stop immediately, pulled over, popped the hood, and let the engine cool down for about 5-10 minutes. Then I turned the car back on with nothing noticeably wrong. No abnormal noises and the car still pulled hard. I (perhaps stupidly) decided to keep driving pretty fast in the mountains for another 1.5 hours or so, drove it home, plugged in my OBD2 reader, and found no error codes using the TorquePro app.

1) I've read several other cases where people have mis-shifted down a gear and over-revved the engine, but none of them mentioned the engine turning off immediately after. Does anyone know why it would turn off?

2) I've read that I should do a valve retainer inspection, a compression test, and a leak down test. But judging solely by my account of what happened, how likely do you all think that the engine may have been damaged?

 

Take valve cover now and check your retainers for sings of cracking (seach for diy on what to look for as no cracks will be visible just the keeper will be little recesed when compared to good retainer) ...dont drive it and do it now!

 

My first thought wouldn't be a retainer issue, if your broke/cracked a retainer and your engine stalled you probably wouldn't be able to start the car or would have noticeable drive issues, and permanent damage to the valves. That's not to say it is impossible but if you never fully entered 2nd it is fairly unlikely.Do you have any mods to the car? Has it stalled before during other spirited driving adventures?

 

It sounds like you misshifted and stalled the engine when the wheels locked up. You need to look at the engine, and from your post, you need to learn how to shift properly - even if you didn't damage the engine this time, it sounds like you could have damaged it one of the other times you misshifted. If you're not sure what's happening in the car, you need to start paying better attention too.

 

from all the confusion you wrote.. ending with the, nothing seemed not working right after and you then drove another spirited 1.5 hours.. i'd go with who knows.. what happen..

checking it seems is always a good thing with this car.. yours may vary with use..

 

Sounds like you just stalled it out to me... if everything is working fine, maybe pull the valve cover and have a look to put your mind at ease. I think the AP2 retainers can handle the overrev better than AP1. Plus, if you went from 3 to 2 at 8k rpm, that only puts you at overrev to about 9k-ish (if Im not mistaken). I remember Billman saying the damage is caused if you put the engine into the 10k+ range (bent valves, cracked retainers etc). I did a "money shift" at 8800 rpm when my AP1 was at 60k miles. I have 250k on the same motor now and have not had any problems with the valves or retainers etc... so, you could be lucky and have missed doing any serious damage. Just don't do it again!

 

Thanks for all the input! I don't think anything was damaged. Like some of you said, I'm pretty sure I just stalled it due to the tires locking up. I will do a valve check as soon as I can, but in the meantime I will continue driving it and see if I notice anything unusual.

To answer some of the concerns above:

No, I've never stalled it while driving it before. The 2-3 times I've stalled the car prior to this was from accidentally releasing the clutch while in gear and parked.

The only mod I have installed is Bilstein PSS9 coilovers, which was installed by a previous owner.

I've never had this mis-shifting issue in any other car I've driven before. For some reason the S2000 shifter's short throws make it very easy for me to shift from 3 to 2 and 5 to 4 while meaning to upshift. From now on I'm going to try holding my shifting hand so that the thumb is pointed downward while shifting from 3 to 4 or 5 to 6 and push the shifter slightly to the right, and hopefully avoid accidentally downshifting again.

 

2nd - pull to back left tire
3rd - push to front of car
4th - push toward back of car
5th - push toward front right wheel
6th - push toward back right wheel

You should only be pulling the gear lever on the second-gear change.