Going to battle it out with Mitsubishi

[Trogdor]

So, they're going to try and deny my warranty claim. Here's the full background.

While on the cruise I threw an SES light: p0302 cylinder #2 misfire. Schiedes reset the ECU to clear the code. It came on again (later found out it was P0300 random/multiple misfires). The car seamed fine in 1st-4th. But when I got in to 5th and started to accelerate it would shudder. I could drive it in 5th fine, but couldn't really get on it.

This was probably 30 miles from the hotel when all this happened. Drove it there just fine, staying off the accelerator. On the way home the next day, the rod blew, in 5th gear at about 60-65 mph.

Somewhere on one of the computers (not the ECU) it says the car over revved. The OEM rev limiter in the car is 7599 (redline is 7000). The car over revved to ~7900PRMs.

Being that the car is totally stock, Mitsu is trying to deny my claim based on this over rev. What I'm wondering is how the connection from an over rev could (if at all) lead to a blown rod. Over rev should in theory either spin a bearing or damage the valvetrain, right? Either of those could lead to a busted rod. But I want to see either of those or something else in between is actually the case before they try to deny it, cuz it feels like they're jumping from A to C with out knowing what's in between.

Also, how did it over rev in the first place? I could see if it was at high RPMs and I down shifted several gears and the engine continued to roll on. But that's not the case here.

Or, am I totally wrong and simply the over rev and directly cause the blown rod?

[shurikss]

If your car rev limiter at 7599 , no way you can rev up to 7900 , unless you down shift in high rpms then you can record 7900.

[Trogdor]

This is what I thought too.

[shurikss]

Good luck with battle !!!

[turbotalon1g]

Is there anytime that you went over the stock redline?

[Goat Blower]

It could potentially weaken it to the point of failure depending on exactly how the rod failed. I highly doubt it though, DSM factory rods and pistons have gone way higher than that repeatedly, something else is wrong here.

[scheides]

Revs, high torque load....any sharp, sudden change could lead to problems...theoretically.

I've rev'd both of my evos to 8000 though, that's really not much of an over-rev.

[scheides]

Originally Posted by Goat Blower

It could potentially weaken it to the point of failure depending on exactly how the rod failed. I highly doubt it though, DSM factory rods and pistons have gone way higher than that repeatedly, something else is wrong here.

This is an X remember...not a 6-bolt

[93gtpeater]

Good luck on getting a new motor.

[Super Bleeder!!]

I have a real hard time believing you can throw a rod on those things by running 500rpm over the factory fuel cut.

The factor of safety used to design the rotating assembly is usually enough to accommodate all sorts of unforseen load factors, because its easier to overdesign something than it is to constantly fix it under warranty.

Maybe you had a slightly defective rod from the factory and over time it fatigued and failed.

[Trogdor]

So, I guess the first thing is: is it even possible to over rev it in neutral?

[Murlo26]

You can misshift and over rev as well, free revving essentially.

Ask me how I know

[10EVO]

Originally Posted by Murlo26

You can misshift and over rev as well, free revving essentially.

Ask me how I know

Oh boy haha how??

[Murlo26]

Originally Posted by 10EVO

Oh boy haha how??

Over 9000 when I was getting clutch lockout at the track

[10EVO]

Originally Posted by Murlo26

Over 9000 when I was getting clutch lockout at the track

Damn!!!!!!!!!

[Halon]

Time to back out of that lease.

[Trogdor]

So sounds like it is possible for it to rev past the rev limiter.

The next question is what actual damage does that cause? Things like a spun bearing, floating a valve... What else could an over rev directly cause.

[Kracka]

Didn't you say you missed a gear and grabbed another by accident? That would be a mechanical over-rev, no rev-limiter can stop that.

My theory is that the over-rev damaged a spark plug and then the damaged spark plug caused some crazy detonation damaging the rod.

[Trogdor]

No, it was in neutral. I understand that a mechanic over rev can happen if I were to have downshifted at high Rpms, but that wasn't the case.

[A//// Guy]

You cant over rev in neutral, It just isn't possible unless your factory rev limiter was removed. Maybe you miss shifted and it all happened so fast you cant remember. But that should cause damage to the motor right then, not 50 miles later?