Possible bad torque converter symptoms?

[markj]

Alright. I've been reading as much as I can about the way my transmission acts, and I think I've managed to narrow it all down to the torque converter, or something closely related...

A month after I started driving the car in March of this year, I noticed some shuddering under different circumstances. After driving a mile or so, and around the same time the engine has reached operating temperature, accelerating from a complete stop presents a slight shudder as the car starts to move. Starting up hills, the shudder is sometimes such that the RPMs sputter a little. I also have a leaking flex pipe, which makes the shudder more audible. This shudder on acceleration is NOT noticeable when the transmission is cold, like in the early morning hours after the car has sat overnight. As the car rolls faster, the shudder simply disappears and the engine revs freely as I accelerate. Feels almost as if there's a huge load being lifted off its shoulders.

Also only when warm, at about 40 MPH under constant load and light throttle, there is a slight "bumping" or shudder - almost like a misfire - that occurs until throttle is increased or released. Over time, this shudder at speed has expanded from occurring at only 40 MPH to up to 60 on the highway. Again, this does not happen when the trans is cold.

When cold, the transmission shifts perfectly - at the right RPMs, quickly, and hard as it should. However, as the engine coolant temp needle starts to rise, the shifts become delayed by 100-200 RPMs and are very soft and mushy, and always with a bit of slip on the 1-2; Upon first discovering the shuddering, I changed the trans fluid - all of it at once - with Honda ATF DW-1. The shuddering did not stop or worsen, didn't change at all. That was about 2,000 miles ago.

Over the summer, I noticed one extremely hot day that while trying to accelerate, no matter how hard I pushed the throttle, the engine bogged and the car shuddered hard, until I finally pushed the gas down so far that the "load" just disappeared and the car shot forward. That happened only once that day.

Sorry... I talk a lot. So after researching, I think I might have a bad torque converter. The shuddering seems to be related to the torque converter clutch (?) slipping or engaging and disengaging constantly. And the shuddering on acceleration, maybe that's the TC clutch staying on even to a dead stop and disengaging once I hit the gas? (Never mind) I've noticed that at highway speeds, lifting off the throttle (especially going downhill) will release the lockup, and hitting it again even slightly seems to lock the TC back. Plus when I decelerate to a stop using the brakes, I feel as if the car is trying to work against me - it tries to push forward as the brakes slow the car to a stop. TC staying locked up or something? I'm not very well-versed on how it all works..

I'm really stumped. The car has 218,500 miles. At first I thought the fluid was bad, so that's what made me change it. But after switching to the new DW-1 and not seeing any changes whatsoever, I guess that's out of the picture. I question whether the trans itself is physically bad because when cold, it drives amazing.. it's only when warm that it starts to shudder.

Ideas? Sorry for being so wordy. I'm just reaching the end of the line as to what this could be.

[nope]

Was the fluid that came out really dark and metallic? That would be a good sign that some of the clutch plates are failing.

[wed3k]

if the tc stayed locked at a dead stop, the motor would shut off. it's like keeping the clutch engaged and coming to a stop.

when you're crusing, lockup ill engage and disengage as you hit the gas.

a worn torque converter would "slip" when warmed up.

please make sure the engine isnt misfiring because i went through this on a lexus and went as far as replacing the engine and torque converter only to find out that it was a cracked spark plug that was brand new.

[markj]

Was the fluid that came out really dark and metallic? That would be a good sign that some of the clutch plates are failing.

It wasn't, actually. It was still relatively clean and not a dark shade at all, still red.

if the tc stayed locked at a dead stop, the motor would shut off. it's like keeping the clutch engaged and coming to a stop.

when you're crusing, lockup ill engage and disengage as you hit the gas.

a worn torque converter would "slip" when warmed up.

please make sure the engine isnt misfiring because i went through this on a lexus and went as far as replacing the engine and torque converter only to find out that it was a cracked spark plug that was brand new.

You're right about the TC staying locked. I actually realized that while driving and thinking about it earlier today. I changed the plugs and wires to NGKs (from Champions, bleh) two months ago with no change. However, I do remember now that the last time I had the distributor cap off, the rotor and contacts were very worn and there was red dust indicating the bearing going bad... if that ends up being the shuddering problem, then I'm going to hate myself a whole lot.

But a misfire wouldn't make for mushy shifts.. unless there is an actual reason why the trans shifts so soft when warm, I need to just live with the fact that it's old and has miles. When I find time to ohm out the shift solenoids, I'll post results.

[bravedude]

what i read when the torque convertor is bad you put the car in drive and give no gas, if the car moves without gas it's good. like mine it will stay still for a lil bit then move. so my tc is going slowly but surely.