Any real chance of engine damage?

[Betrayer00GT]

So,

Recently dropped to second gear a bit prematurely and got the engine up to about 6.6K RPM. I was down shifting to slow down, so I didn't have any throttle applied. It was only up that high for a split second before it climbed quickly down as I decelerated with brakes plus engine-braking.

No unusual signs/symptoms, but I was wondering if anyone thought there might be a good chance of un-obvious weakening/damage that I could not tell with my own ears or just by feel, etc.

So, any one think there is a good chance there might be?

 

[shook0002]

If its still sounds good your probably ok. Usually the clutch will explode b4 the motor with a downshift like that.

 

[mity2]

i'd run compression check. If your valve got intimate with piston, compression check would tell ya

 

[the98stang]

So,

Recently dropped to second gear a bit prematurely and got the engine up to about 6.6K RPM. I was down shifting to slow down, so I didn't have any throttle applied. It was only up that high for a split second before it climbed quickly down as I decelerated with brakes plus engine-braking.

No unusual signs/symptoms, but I was wondering if anyone thought there might be a good chance of un-obvious weakening/damage that I could not tell with my own ears or just by feel, etc.

So, any one think there is a good chance there might be?

Honestly I wouldn't worry about it. If you did any serious damage, you would know, trust me. If you are really worried about it, do a quick compression check to see how the engine looks. Although, even there is damage, you would never know what actually caused the problem. I say you drive it like you stole it.

 

[Betrayer00GT]

So, seems like the agreement is "likely ok - want to check, do a compression test", right?

So, related question:

What is a good compression value for a 2000 GT with <56K on it? I believe my compression is less than an 01+, but what exactly would I be looking for?

Second, what does everyone think of buying something like this from HF (they are local) so I can check when I want? I am not worried about using it, I installed the spark plugs that are in there now. I can remove/reinstall them to use this thing.

If not the HF unit though, where and how much?

Thanks guys.

:SNSign:

 

[mity2]

unless your car was running funny before, exact compression value is unimportant, as more then likely your compression was fine before.
Just run the test. And make sure that lowest reading cylinder must be within 15 psi of highest reading cylinder. If more then that, then add bit of oil to cylinder. if compression returne significantly, then you have ring issue, and if compression don't return, valve dmg is more then likely

 

[Barrier]

Just go grab a compression tester from autozone or something for 20 bucks... it's easy as pie for these cars. Takes about 45 minutes if youve ever changed your plugs before. Some people say to grab an exact amount of spikes of the needle, like around 6, and some people say to keep cranking the car until the needle stops... either way you'll know if theres a problem with one cylinder. Also remember to disable the fuel injectors/supply unless you want fuel to be squirting into the cyls while the plugs are out

EDIT: Yeah... harbor freight is very cheap quality but it's a compression tester. It's gonna be 20 bucks pretty much anywhere.

 

[5spd GT]

If you didn't or don't hear of 'feel' anything, don't sweat it.

 

[the98stang]

unless your car was running funny before, exact compression value is unimportant, as more then likely your compression was fine before.
Just run the test. And make sure that lowest reading cylinder must be within 15 psi of highest reading cylinder. If more then that, then add bit of oil to cylinder. if compression returne significantly, then you have ring issue, and if compression don't return, valve dmg is more then likely

I believe you want to compare the AVERAGE of all the numbers combined with the lowest number. Then if the difference is more than 15%, you have a problem with either the rings or valves.

 

[Barrier]

Or head gasket

srsl though... the compression test is just a double check. If your cars running, and not making any death notes, you're perfectly fine.

 

[rugster]

I spun a rod bearing by shifting into 2nd instead of 4th on a WOT run....rpms went all the way around Spun a rod bearing, blew the motor, but if you dont hear the ticking, and only went to 6600 I wouldnt sweat it. Good luck

 

[RedDaemon]

funny...i did the same exact thing today..only i caught it at about 4-5k (i think )

you should be fine

 

[Betrayer00GT]

Well, the drag strip didn't shake anything loose, as I feared it might.

14.3 was the best I could do ( ), but the conditions at Sacramento Raceway for the Street-legal Fun Drags tonight were fairly bad. From the dead 60' sensor in the lane I used every time but the last one, to the complete lack of track-prep (normal for Wednesdays), to the fact that I didn't get a run in after 7PM - which was way before the weather really cooled down.

Anyway, seems nothing is majorly wrong with the stang, or I never could have even pulled that out of it. I am happy. Not ecstatic, but definitely happy.

Fun was had by all; me and my newly reunited brother.

 

[showstopper2]

how could the car rev that high without bouncing off the rev limiter? the car is set with a 6250 limiter unless you have a chip and had it changed.

 

[SVT32VDOHC]

The car had to hit the limiter. IF the tach said 6,600 it could have just jumped. Stock tachs are not as accurate as the aftermarket tachs. If you motor runs fine, don't worry about it.

 

[BennyBlown2v]

I spun a rod bearing by shifting into 2nd instead of 4th on a WOT run....rpms went all the way around Spun a rod bearing, blew the motor, but if you dont hear the ticking, and only went to 6600 I wouldnt sweat it. Good luck

Lol I did that in my old SVTf when some douche bag cut in front of me when a car club I was in was caravaning (literally 30 cars all in a row, in the right lane...) to a car show - 5-2 shift = BOOM! Luckily the knock sensors killed the motor and I coasted to a safe stop....but it did rev out to 9k rpm or so before it cut off haha! Those motors are damn stout though...

And guys, the rev limiter is only for when you're powering the car, its so it doesn't give it enough fuel/spark to keep gaining RPM - when you downshift the speed of the wheels is directly translated into engine RPM. So, it is physically causing the motor to rev higher....rev limiter has no use then, because you're already going faster (MPH), and the rev limiter itself can't do anything about that.

 

[Betrayer00GT]

And guys, the rev limiter is only for when you're powering the car, its so it doesn't give it enough fuel/spark to keep gaining RPM - when you downshift the speed of the wheels is directly translated into engine RPM. So, it is physically causing the motor to rev higher....rev limiter has no use then, because you're already going faster (MPH), and the rev limiter itself can't do anything about that.

Exactly, it was mechanical with the tire speed spinning the engine too fast. It had nothing to do with how much I was on the throttle (which was not at all).

Also, my tach tells me I have an idle of ~950, so it probably reads high. The previous owner put in a white gauge face sheet (with the cobra redline, which I didn't reach - lol) in my GT, so that could have tweaked its accuracy a bit, if nothing else does.

 

[5spd GT]

Yeah, you could have revved right at the 'potential' rev-limiter...

You don't set rpm at idle with installing new guages, which I'm sure you know You should set it at a higher rpm cruise, like 3,000 or so.

 

[mity2]

how could the car rev that high without bouncing off the rev limiter? the car is set with a 6250 limiter unless you have a chip and had it changed.

Would not have mattered.
He said he downshifted in to 2nd prematurely and got the engine up to about 6.6K RPM while car is moving.