2kobw: auto trans can't decide on a gear

[hustler]

I searched through the forum, and apparently this problem is unique. The trans can't seem to pick a gear. Half the time the engine turns more rpm than it should for the gear...imagine slipping the clutch as you go down the highway. Then if it goes to 4th, it will cut to roughly 50% of what rpm should be. I can go 80mph down the highway in 4th, and the engine will turn 2000rpm. The trans also can't decide if it wants to stay in 4th, or drop down to 3rd when cruising.

 

Also, the car builds rpm slowly, like there is resistance somewhere, slowing acceleration. I have to cruise at roughly 3/4-throttle position to maintain highway speed

 

I've replaced the ATF and filter (although this did not trigger the issue), attempted to reset the computer by disconnecting the battery and leaving the car to sit for a few weeks, but not hooked it up to an obd scanner. I did a brake job, all the way around, then this problem started. Where should I start to diagnose this problem?

 

Thanks

[idosubaru]

the issue started immediately after a brake job?

most of the time if that's the case, then something happened to cause it.

 

mileage?

 

are all the tires matching in size and tire tread depth/wear/pressure?

 

has the check engine light come on at all during this time?

 

if so, read the codes and let us know what they are.

 

have you checked the fluid - was it ever low or leaking?

 

have you ever run mismatched tires on this car or has it been towed?

 

does the POWER/AT/TEMP light, or whatever the trans light is for a 2000 OBW flash 16 times when you first start the car?

 

if so - you need to pull that code.

[hustler]

the issue started immediately after a brake job?

most of the time if that's the case, then something happened to cause it.

 

mileage?

 

are all the tires matching in size and tire tread depth/wear/pressure?

 

has the check engine light come on at all during this time?

 

if so, read the codes and let us know what they are.

 

have you checked the fluid - was it ever low or leaking?

 

have you ever run mismatched tires on this car or has it been towed?

 

does the POWER/AT/TEMP light, or whatever the trans light is for a 2000 OBW flash 16 times when you first start the car?

 

if so - you need to pull that code.

 

153k miles

same size tires

no idiot lights

ATF was never low

I need to take it somewhere to get the codes pulled.

[nipper]

Sounds like a clogged cat. Put a vacume gauge on the car then tell us exactly what it does when the condition happens.

 

Any CEL lights?

 

Any flashing tranny light at startup?

 

What happens if you downshift to 3rd?

 

 

nipper

[subyfreak]

Jack up the car and see if your wheels are easy to turn by hand and the brakes not dragging or just drive it and check the wheels to see if one is getting hot. Possibly e-brake not releasing all of the way? Just some ideas.

Edited February 2, 2009 by subyfreak

[hustler]

Sounds like a clogged cat. Put a vacume gauge on the car then tell us exactly what it does when the condition happens.

 

Any CEL lights?

 

Any flashing tranny light at startup?

 

What happens if you downshift to 3rd?

 

 

nipper

 

no lights of any kind

If I drop it in 3rd, it revs slowly, then stays in gear, but rpm changes independent of wheel speed.

 

I'll have to put the mechanical boost gauge on the intake plenum and let you know what I get...but that may take a couple weeks because I'm out of town.

 

Obviously this is something really weird and atypical.

 

Thanks.

[hustler]

Jack up the car and see if your wheels are easy to turn by hand and the brakes not dragging or just drive it and check the wheels to see if one is getting hot. Possibly e-brake not releasing all of the way? Just some ideas.

 

the brakes do not drag. How should the wheels behave when I spin one, I'm not accustom to the AWD system in these cars.

[rverdoold]

I go with Nipper, Had a blocked muffler once and gave very similar results/problems.

How is the throttle response in neutral, quick or hard to get in the higher range. Problem is that the air can not get out as quick.

Hope its the muffler and not the cat since cats are very expensive. (not the onces that say miauw).

[hustler]

I go with Nipper, Had a blocked muffler once and gave very similar results/problems.

How is the throttle response in neutral, quick or hard to get in the higher range. Problem is that the air can not get out as quick.

Hope its the muffler and not the cat since cats are very expensive. (not the onces that say miauw).

 

It revs fine in neutral and will bury the tach as expected...but you guys are right about it driving like the cat is clogged although this problem occurred suddenly.

 

Can I just unbolt the cat at the downpipe, leave the 2nd o2 sensor outside the exhaust pipe, and not get a code/limp mode? That would be an easy way to rule-out the clogged cat problem.

[nipper]

It revs fine in neutral and will bury the tach as expected...but you guys are right about it driving like the cat is clogged although this problem occurred suddenly.

 

Can I just unbolt the cat at the downpipe, leave the 2nd o2 sensor outside the exhaust pipe, and not get a code/limp mode? That would be an easy way to rule-out the clogged cat problem.

 

You could, but since modern cars are so quiet, when you run with an open pipe they are so incredibly noisey in comparison. A vac gauge is a much better tool for this.

 

nipper