Blew my valves
#41
Racer
Join Date: Jul 2006
Location: Phoenix...Greatest City on Earth
Age: 72
Posts: 362
Likes: 0
Received 1 Like
on
1 Post
Originally Posted by Formula 350
In my old Formula... which is an auto... I downshifted into second at about 80 mph by mistake... the RPMs did not go over redline, but the wheels were locked and sliding... only for maybe 1 to 2 seconds before I got it out... no damage at all...
Just curious why wheel lock would not occur??
Just curious why wheel lock would not occur??
And I disagree with the previous statement about damage from a missed shift not being covered by warranty. If the shifter fails, it should be covered.
#42
Dragging knees in
iTrader: (2)
Originally Posted by chfields
It won't/can't keep you from manually downshifting, but it's supposed to cut the power when it reachs a certain rpm, regardless of how you do it.
When you misshift into a lower gear while accelerating, say from 4th to 2nd, the opposite happens; the vehicle's moving speed is dictating the engine RPM speed... Let's say you're going about 80 mph and try to go into 4th but go into 2nd gear... well, 80 mph in second gear would require something like 11,000 RPM (just guessing here, but you get the point)... which the engine is not built for. Shit starts flying around, the valves can't keep up and come in contact with the pistons because the J-series is an interference engine... buh-bye.
So basically, the rev limiter really can't do anything when you misshift. All it can do is cut off fuel... when you misshift, fuel doesn't matter. It's only about engine RPM speed, which is too high for the components to withstand.
#43
SSM 6MT
Sorry to hear about your misfortune. It won't hurt to keep pushing Acura that it wasn't your fault for mis-shifting. This problem has happened since at least 2000 with the release of S2000's that I know of. I've heard of RSX drivers having the same problem. Most cases, Acura/Honda covered labor and you just have to cover parts.
#44
Senior Moderator
Accidents do happen. Sorry to read of your misfortune. If there's a good independent Honda garage in your town, now's a good time to get a quote.
#45
Safety Car
Originally Posted by Formula 350
In my old Formula... which is an auto... I downshifted into second at about 80 mph by mistake... the RPMs did not go over redline, but the wheels were locked and sliding... only for maybe 1 to 2 seconds before I got it out... no damage at all...
Just curious why wheel lock would not occur??
Just curious why wheel lock would not occur??
But they are right,FWD pushes all the weight down when you do this on the front wheels, so the tires actually do not lock up but it forces the engine to overrev.
#46
Originally Posted by KJSmitty
What was the RPM logged during the alleged mis-shift???
Floating the valves resulting in a decrease in immediate compression is one thing . Floating the valves resulting in them striking the piston is another..
Not an expert on the TL engine by any means but I would speculate floating to the point of contact with the piston would require several 1000's of rpm above the redline etc..
Is a Honda "V-tech" more susceptible to this????
I'll be interested to read the outcome on this one Papaman - Raise heck with Acura, after all, it was partially due to a known trans issue (whether your dealer admits it or not...).
Good luck!
Floating the valves resulting in a decrease in immediate compression is one thing . Floating the valves resulting in them striking the piston is another..
Not an expert on the TL engine by any means but I would speculate floating to the point of contact with the piston would require several 1000's of rpm above the redline etc..
Is a Honda "V-tech" more susceptible to this????
I'll be interested to read the outcome on this one Papaman - Raise heck with Acura, after all, it was partially due to a known trans issue (whether your dealer admits it or not...).
Good luck!
#47
Originally Posted by TL Jones
V-tech has a much longer duration of high valve lift. The longer the duration, the closer the piston comes to it, before it closes. A price we pay for performance.
Originally Posted by ubnpast
^ Vtec, vtech is a phone
#48
Intermediate
I'm sorry to hear about your story. I read this thread a few days ago, right before I bought my TL and it has stuck in my mind since then. I have been driving sticks for over 16 years and I don't believe I had ever miss-shifted on three separate cars that I have owned 4-spd, 5-spd, and 5-spd. Then on the second day owning my TL, I noticed that I had done a shift from 5 to 4 when I was expecting to go from 5 to 6. Luckily, I was going slow on an on ramp getting on the freeway and the RPMs never exceeded even 5K. I was originally in 6th doing probably 45 or so and downshifted to 5th to pass someone, then I meant to return to 6th and got surprise with going into 4th.
I can chalk it up to not knowing the car very well yet, but as soon as that happened, I thought about this thread. I was pondering how in the hell after 16 years of driving a stick I can't recall this ever happening before... Maybe a very few rare times (couple times a year) I might get a grind because of miss-timing clutch with stick (I would guess this occasionally happens to everyone?).
I'm thinking that this miss-shift phenomenon has to do with the fact that the shifter is a short-throw (or “shorter-throw” than most) and the ergonomics of the cabin in relation to your arm/hand and the position of the shift knob. In every day use, I find it incredibly difficult to tell what gear I am in (or gear I am going into) compared to many other manuals I have driven in the past.
Anyway, ever since this little eye-opener and reading your thread I have made sure to put a little extra push to the right when going from 5 to 6 or any other shift requiring pulling down. Usually pulling straight down is fine in most cars, but straight down seems to sometimes lean to the left. I am assuming this can happen with the other pull-down shifts, also.
While we are on the topic of shifts---I have always been able to do a double-downshift in my past cars as long as the car is going slow enough such as a 5 to 3 or 4 to 2, for extreme acceleration such as passing someone on a one-lane highway when you need max power. It is not something I have done regularly, but I was never worried doing this in past cars as long as the RPMs were low enough. Does anyone do double-downshifts without having issues (the assumption is that you are not doing this when RPMs are already high)?
BTW, good luck with getting your car serviced. I am curious to know what something like this costs, if you are willing to share. My sister had a 93’ Honda Prelude when a timing belt blew and it trashed her engine so she had to get a valve job.
I can chalk it up to not knowing the car very well yet, but as soon as that happened, I thought about this thread. I was pondering how in the hell after 16 years of driving a stick I can't recall this ever happening before... Maybe a very few rare times (couple times a year) I might get a grind because of miss-timing clutch with stick (I would guess this occasionally happens to everyone?).
I'm thinking that this miss-shift phenomenon has to do with the fact that the shifter is a short-throw (or “shorter-throw” than most) and the ergonomics of the cabin in relation to your arm/hand and the position of the shift knob. In every day use, I find it incredibly difficult to tell what gear I am in (or gear I am going into) compared to many other manuals I have driven in the past.
Anyway, ever since this little eye-opener and reading your thread I have made sure to put a little extra push to the right when going from 5 to 6 or any other shift requiring pulling down. Usually pulling straight down is fine in most cars, but straight down seems to sometimes lean to the left. I am assuming this can happen with the other pull-down shifts, also.
While we are on the topic of shifts---I have always been able to do a double-downshift in my past cars as long as the car is going slow enough such as a 5 to 3 or 4 to 2, for extreme acceleration such as passing someone on a one-lane highway when you need max power. It is not something I have done regularly, but I was never worried doing this in past cars as long as the RPMs were low enough. Does anyone do double-downshifts without having issues (the assumption is that you are not doing this when RPMs are already high)?
BTW, good luck with getting your car serviced. I am curious to know what something like this costs, if you are willing to share. My sister had a 93’ Honda Prelude when a timing belt blew and it trashed her engine so she had to get a valve job.
#50
Racer
Originally Posted by chfields
How can that happen if there is a rev limiter? I understood that the TL has a rev limiter to prevent things such as this. Well, I'm sure he'll learn to be more careful shifting in the future. Expensive lesson.
Heres a video of an RSX Type S Mis shift.
http://cometvr4.freeyellow.com/RSX-S_misshift.mpeg
#51
When I was buying my car, the salesman told me that just a week previous he had a test driver blow the engine in a new 6MT TL by shifing from 3 to 2 at redline by mistake. He said it nearly put him through the windshield.
#52
The DVD-A Script Guy
Originally Posted by CometVR4
The owners manual clearly explians how the rev limiter works. It says in bold it would not prevent over-revving in mis-shifts.
Heres a video of an RSX Type S Mis shift.
http://cometvr4.freeyellow.com/RSX-S_misshift.mpeg
Heres a video of an RSX Type S Mis shift.
http://cometvr4.freeyellow.com/RSX-S_misshift.mpeg
Originally Posted by BG74
When I was buying my car, the salesman told me that just a week previous he had a test driver blow the engine in a new 6MT TL by shifing from 3 to 2 at redline by mistake. He said it nearly put him through the windshield.
Not to be an asshole but a you gotta miss really bad and be wandering around red line to blow the motor. I've (and probably lots of others have) "found" 6th-->3rd instead of 6th-->5th on the highway and all I get is startled and embarrassed. Yeah, I push the car sometimes too but missed shifts on acceleration gotta be a byproduct of racing, showing off or speed shifting. That always comes with risk.
Thread
Thread Starter
Forum
Replies
Last Post