trekking

Hi guys, (my first post! I am from New Zealand!)

I am having a bit of a transmission problem on my Airtrek Turbo. It's only done 15000km, but I am getting a thump when I shift from 3th to 4th. It's automatic INVECS II 5 speed version.

I don't know if I had this problem from brand new, as I had to reset my ECU many times due to alarm, audio, tuning, mods, etc installs and I resetted ECU to pick up new stuff.

The Mitsubishi guys did say that there is something wrong, but after a week (calling Japan), they are still waiting to hear from a techie in Japan.

When I had my oil catch can installed, I did not make it a closed system, and got the catch can with small air filter on top, thus losing the fume. Thus there is the inlet tube from engine to the catch can, and the other outlet tube is into atmostphere. The outlet plug-in on throttle part (after AFM) has been blocked off by ball bearing and some silicon tube.

Can this cause any problems when shifting gears? I have no other problems than shift shock from 3rd 4th. All other gear changes are normal. The gear change shift up only happens when I am crawling or having very low revs.. i.e. going 3rd to 4th at 40km/h. If I give it some rev before I shift up manually (tiptronic) it changes smooth. When I accelerate from 0 to 100, it's smooth once again. Only does it when I go slow crawling up in constant light throttle. (shift shock I am talking about).

No other problems. ECU reset gives smooth ride for about 1000km, but the problem comes back. Can't figure out what it is?! Also when the car is cold, gear change is sweet. Only happens when warmed up. I can do manual mode drive all the time without getting thump by changing throttle, giving it some rev.

It can't be damaged honeycomb on AFM right? Well, I don't think I damaged it, but heard a lot of denting it with screw driver etc... I don't think I did that, (or my friend)... my idle is always smooth and power band through out rev to 7000rpm is sweet as.

So the symptoms: of shift shock / slight thump when shifting up from 3rd to 4th gear either manual or auto mode. When..
1) light speed crawling at 40km/h, light constant throttle either manual or auto mode
2) down hill, slight throttle going down.
3) When I accelerate fast from 0 to 50 then let the throttle off, then it stays 3rd then shift shock to 4th. I have to massage the throttle to make it shift smooth.

It's fine when...
1) Driving on motorways from 0 to 100km, or any moves at faster speed than 60km. When there is enough rev and throttle -> smooth
2) When I drive manual mode, and give it some rev before shifting from 3rd to 4th (that's what I am driving around in..) it's smooth
3) Reset ECU, and it's smooth for about 1000km no matter how I drive.
4) When cold and not warmed up, the shift is always smooth.

Once the shift shock starts after ECU reset, it's always there as if ECU has picked it up as my behaviour and tries to generate it more often..

Not sure if this is tranny issue or ECU issue.

Or from any of the modifications.. (airfilter + box / grounding kit / oil catch can / cat bypass etc / boost gauge install)

If you have any experience on automatic trans please let me know.
My car is still under warranty for next 2 years... but I really want to get this sorted out ASAP. Mitsi on the shore, have no idea at the moment, and not even willing to give me free trans oil change to test it out. (I talked about torque convertors before, but they said no. I should be getting shudder.. so I guess that's not it?)

Cheers.

trekking

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