Transmission - OD troubles

I've been reading about everyone's overdrive troubles with their transmissions, now it is time to post mine. It has just started this within the past 2 weeks. The car has no problem shifting into overdrive most of the time. Occasionally, it will slam into OD, namely if the throttle load is low and I'm under 50 mph, but this is only maybe once a week and I drive 800 miles/week, so I don't mind that. The real problem is that it won't stay in OD when I give it the slightest amount of gas. I used to be able to give a small amount of gas and have it accelerate without really changing the RPMS. Now, especially when I'm going up a slight grade at around 60mph, if I move my foot the slightest bit into the throttle, the rpms will go up a little bit, like maybe 100rpms max and then a second later drop back to where it was before. If I keep my foot there, it will continue to do this over and over until I either back off to almost no gas, or give it enough gas to allow the torque converter to unlock (i think that's whats happening) and increase RPMS to about 2500 - this is not 3rd gear. The jump in rpms to at least 2500 is normal when I give it more gas, but its the jump up by 100 from 1900rpm and back that worries me. Sometimes, when it falls back, I can feel it shudder a little.

My guess would be something with the torque converter clutch not locking properly, possibly the solenoid not telling it what to do or maybe a mechanical problem. The last time I had a fluid change was around 60k miles (about 18 months ago), now I have 96.5k miles. I do mostly highway driving, so lots of overdrive, which means I don't want to have real problems with it. Pretty soon, when I get time, I'll take it in and have a fluid change and have some lubeguard put in as well. I also have a bad pressure control solenoid, which acts up usually once a week and causes hard shifts when it isn't functioning. I wonder if it might have something to do with my other problem. Let me know what you guys think. by the way, for those of you who haven't read my posts before, its a 2001.

Two possibilities both require a full scan, the tps could be skewed fooling the pcm to kick out of o/d or there could be internal trans issues, the scan for the trans functions will need a scanner with programming capable of getting into the trans functions. I wouldn't worry about a trans service till the root cause is uncovered. BTW this sounds more like TCC engagement than o/d. But same diagnostics apply.

I thought about the throttle position sensor, as many other owners have had problems with it. I will get it checked. I say it is an overdrive problem because it happens only in overdrive, but yes, it does seem like tcc problems. Another thing, which could just be normal as it has happened for the 2 years I've had the car, after driving for a little bit in traffic, the torque converter is slow to react and clunks when you give it a little gas at speeds of 10-20mph, causing driveline lash.

Although worth a try the TPS very seldom if ever corrects the problem you are having with TCC operation. The TCC lock and unlock functions are only supposed to work in 4th - OD at speeds above 45 mph so it is overdrive related but technically not an overdrive problem. It sounds like ole TCC "fishbite"/"chuggle" problem. Other possibility is you could have a torque convertor with internal problems. As maxwedge pointed out get it checked out because there are many factors, variables or components including secondary ignition engine related that can cause the fishbite.

The transmission in my 1999 Intrigue also quit shifting into OD at 120,000 miles. I had the transmission replaced and all was well; it now has 154,000 and I would like to keep it until around 200,000. That was my solution; not cheap but effective.

The transmission in my 1999 Intrigue also quit shifting into OD at 120,000 miles. I had the transmission replaced and all was well; it now has 154,000 and I would like to keep it until around 200,000. That was my solution; not cheap but effective.

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