tootall

My Lancer has 112k miles and has been a great car but the transmission is possesed. It will shift very rough and get progressivly worse as you drive it. It will shift so hard, it feels like you are being hit from behind. If I let it go, I''m afraid it''s going to break a motor mount.
If I pop the battery off and then reconnect so the ECU resets, it will drive like a brand new car and shift smooth as silk for maybe a day or 2. Then is will slowly start shifting rough again but very slightly and get worse, the more you drive it. The longer you drive it, the worse it gets. I have to pop the batter every 2 days or so to keep it driving smooth. I took it to the stealership and they charged me 200 bucks to change the fluid and re-flash the TCU but it still does it. The tech said he has never seen this before. Since it drives so smooth after a reset it can''t be mechanical, right? Has anyone ever seen this? Does the main ECU control shifting? The car is totally stock with no mods.

doctorjon

Did the people at the dealership check for any bad mounts? Could be numerous of things. Don't just think the only issue lies with the ECU. Sounds like it could just be a worn tranny. Did they check for normal fluids?

Jehuty

iTrader: (3)

I had this same problem, your best bet is going to be to put some seafoam in the tranny, and drive for a couple of days, then change it yourself. I don't think it's a bad mount, but mine still does it but it's not as bad, but it's only going into 3rd gear. Try what I said though and when you're checking it SMELL for burnt oil.

tootall

Yes, the dealer tech said I needed tranny flush since it has over 100k miles, so they pumped it out and refilled it. He said my old fluid looked fine. Strange that he was a dealership tech and said he has never seen this issue before. The motor mounts look good but it is bizzare that it shifts so smooth during driving for an entire day after an ecu reset. The next time the car is shut off, then started again it will get a little worse, then much worse each time it shuts off and restarted until it gets so bad it becomes undriveable.
It almost feels like the gear is shifting up then down, then up again but very fast, like it can't decide which gear it wants to go in or the command that is telling it to shift is stuttering.
If anyone has any ideas please post. Im going to try a different dealership and see if they can help.

I appreciate the feedback!

*02Lancer*

iTrader: (3)

Being that the car will shift fine at first and as it learn's it Progressively goes down hill I would say that Mechanically/Hydraulically you are fine. Do you notice the problem at a certain RPM or point? Does the problem happen at different RPM and intensity according to throttle position?

Green_Bandit

iTrader: (25)

My car is doing the exact same thing!

tootall

No, it seems to shift at the correct rpm's up and down. I am trying to find a used ECU since I have heard the PCM ( the dealership caled it a PCM, powertrain control module) is actually located in the ECU under the center console.
I have done some more testing with it and can do a reset (I pull the battery positive cable, turn the key to ON to drain and power, then turn back off and reconnect battery) and after a reset, it will shift all the way up and all the way down, even manually with the D2, d3, etc. and it is as smooth as silk. Honestly it drives like a brand new car for about a day, or 20 or so miles. Then if shifts with a jerk, but very slight, then gets worse and worse as you drive.
I let it go for 4 days straight and when it shifts at a high rpm, it will actually sqeaul the tires when it shifts. My son thinks its cool. I'm scared it will break a motor mount or one of the cv joints.
It has to be the computer....

Im going this weekend to find a used ECU.

I'll post more once I swap it out.

Green_Bandit

iTrader: (25)

That's the conclusion I'm coming to also. But On the other hand it just doesnt make since that all of a sudden something in the ECU would go bad. I'm modded and my tranny is doing the same thing youre unmodded and doing the same thing.

There has to be some common condition. I took it to a tranny shop and the guy there there shot me some bull**** and said my problem is "internal". I asked him Why does he think that and he said it could be a number of things and passed me a quote the whole time I was thinking "then how come is it when I reset my ECU the problem goes away?"

As some advice when you're driving and your car goes to shift before the shift take your foot off the throttle and the shift will not as be as hard but there will still be that knock.

If you happen to come up with a solution be sure to let us know.

Jehuty

iTrader: (3)

Nobody listened to me.....lol.

I HAD this problem and it went away after the seafoam. You guys have to realize that 80% of the time when you take it to a dealership all they do is unplug and plug the battery and just reset the ECU. Try changing the fluid yourself, when I did it I had some dirt come out. Do this guys when your car is cold feel the shifting is it AS bad? Or is it worse when the car is warmed up?

luischav3z

iTrader: (3)

well i have that problem too but it threw up a code for Solenoids electrical malfunction.. the Service engine soon light came on.. I had some problems with the solenoids inside the tranny.. the guy at the tranny shop just replace them and now it shifts like new.. maybe the guy at the tranny shop GREEN BANDIT went its correct cause me too the shift was like being hit from behind I disconnected the battery and connected it when good for about a day until it did the same thing.. I just leaved the problem thought it could fixed by itself but the rough shifting became more constant.. Im not sure if this is even as close as what its happening to you but it can give you an idea..

luischav3z

iTrader: (3)

it was about $300 bucks..

Jehuty

iTrader: (3)

it's all good. How much was that?

Green_Bandit

iTrader: (25)

I think I'll give the Seafoam and a flush a try.

On a side note I think the hard shifting happends when its cold and gets lighter when the car warms up.

But one thing still confuses me. Why the hell would an ECU reset make it go away but eventually come back? And why would that make the tranny start beating itself up?

Jehuty

iTrader: (3)

That's why it's related to the solenoid, if it was something wrong with the transmission itself the problem would be there no matter what you do.

luischav3z

iTrader: (3)

so is it better now?? any updates