Haven't had much luck finding info on this. Back in the spring I bought my wife a 97 TJ/auto. Seemed to run great and it was in good shape. Then back in August, I think, it started idling rough in gear and threw a TCC solenoid code. Cleaned IAC, checked TPS, dug a little deeper and asked around on some Jeep forums. Seemed the Converter lockup solenoid was to blame. Jeep no longer offered the part, so I bought an Airtex from rockauto. I replaced the solenoid and filter. Problem seemed worse afterward. I then did a little checking after talking to a few guys, and found that the solenoid I removed (which was an aftermarket) would close up when heated to around 200F.

I then found two companies online selling the OEM solenoid. Both returned my money after they realized they didn't have it, and couldn't get it. So, I bought a Borg Warner from O'Reilly. Comparing it to the two previous it looked identical. Same stampings on the metal, however the plastics looked slightly different, and when heated up to 200f it seemed to function properly. So, I put it in with another new filter, and no change.

When it's cold, everything works just fine. As soon as it warms up, it almost dies when coming to a stop, then slowly recovers. Put it in reverse and it dies.

This was supposed to be my wife's daily driver. She takes the kids to her parents quite often. I no longer trust this vehicle. I guess I should have listened to that little voice in my head saying don't buy a 90's Mopar auto.

Just thought I'd see if anyone on here could offer any advice before I sell and let someone else sort it out...

thanks!

That sounds like the torque converter clutch is staying fully or partially engaged when you come to a stop. It should disengage anytime it sees the TPS show you let off the gas and the eng is at idle and also anytime it sees you stepped on the brake pedal. How does the fluid look. It can be the cooler is partly clogged as I have seen it cause the fluid press to cause the lock-up clutch want to apply some when it is off from the cooler being clogged up some and restricting fluid flow and I have see it cause it to be worse in reverse. But if the solenoid is staying closed it may be causing your problem also. The pressure to the lock-up solenoid circuit and the lock-up valve on yours should come through the 1-2 shift valve as it wont let the lock-up valve get fluid pressure to work until it shifts into at least second and then the fail safe valve which is also part of the lock-up circuit wont move over for lock-up until it shifts into third and then the 2-3 shift valve sends fluid pressure to the fail safe valve. The lock-up solenoid blocks a fluid vent when on so if it sticks closed it can cause the lock-up converter to come of to slowly by not letting the fluid pressure vent out of the circuit which may also cause it to still be partly on when you come to a stop. Hope this helps some. Also many cooler lines have a factory check valve in them that can also get clogged some so you may want to check it. You may have to do some pressure check testing. Ron

Thanks. Someone on another forum suggested a clogged cooler. What gets me is that it seems to function fine till it warms up. I did unplug the solenoid and the problem persisted. Also, the problem appears before the solenoid should ever be engaging.

So, now you have me thinking the problem might be in the cooler. If it is, and not in the lines, I should be able to just loop the hose and bypass the cooler temporarily and see if the problem goes away, correct?

Did a little more homework. The check valve is built into the hard line to the cooler and is known for causing problems. Seems it usually sticks open and drains back. Going to first try bypassing the cooler. If that doesn't work, going to cut the line behind the valve and bypass it. If that works, there is a Mopar replacement valve. Just need a hose barb to thread into it.

You are right as the check valve does stick open sometimes and cause to much drainback but thats not to say it cant stick closed or be a point that could clog. Yea you can bypass the cooler and line and just drive it easy around town a little as not to make to much heat in the trans system since your driving around with no cooler. Just drive it nice and easy while driving with no cooler and see how it does like that. You can also try flushing the cooler to test it or unhook the cooler return line at the trans and start it in neutral with the unhooked cooler line at the trans in a bucket as you can see how much fluid it pumps in 30 seconds. The spec is in the service manual for your trans. But for you its most likely easy enough to just bypass the cooler and drive it around to see if its better. Good luck , Ron

I think I made some progress. I found the check valve is threaded on the end of the pressure side hard line. I pulled it and found that roughly 10psi of air would open it. Have no idea what it will flow though. I also managed to blow through the cooler with my mouth. Didn't seem like any restrictions. However, I was not able to blow throw the check valve with my mouth, only an air hose.

I then put the check valve back and ran the hose from one hard line to the other bypassing the cooler and drove around the yard till it would have died before in reverse. Stopping in drive was almost normal and putting it in reverse was about like it was in drive before. Other than no cooling, it could be driven this way. Before it would die.

I think I'm going to see if I can find a hose barb to put in place of the check valve. I'm wondering if maybe I cleaned it out some, but it still isn't flowing enough.

Well, I swapped out the check valve for a hose barb. No change. It's driveable, but not right. Think I may have other problems. I've noticed that it seems to rev up around 1500-2000 as soon as I put in nuetral. After a few seconds it settles back down. Now, I'm wondering if I have a vacuum leak or bad TPS.

Well if it is the converter trying to apply at idle which it kinda sounded like by how you told it but that dont mean it is. But it would feel like your letting the clutch out in a stick car if it is the converter clutch coming on any. It may also feel like the car wants to move some. But if it dont feel like that of course its alot of things that can just make the eng want to stall at idle. Ron

Yeah. That's pretty much it. What was kinda throwing me off was the jumping idle, but I guess the computer is trying to keep it running with the clutch engaged. So, when I shift to neutral it's over compensating for a few seconds.

The guy on the Jeep forum is a trans guy. Said he checked some manuals and it sounds like either the solenoid (which I've replaced twice, but can't say either wasn't bad somehow), blockage in the valve body or a clogged governor screen. Basically, I need to open it up some and clean it out.

I just really don't have the time or desire right now. May just let it sit a little longer till I can get to it...

I'm still not sure why it runs fine cold. Unless there is blockage and it shifts around. Or that solenoid is getting hot and locking up. Almost tempted to pull the solenoind out and try it. Just hate draining the pan. Should get a plug kit if I'm going to be doing this often.

Just thought I'd bring this back to life. I think I'm going to have some time this weekend to work on the Jeep.

I've since found two different guys with the exact same symptoms. Both of them had clogged coolers, and after going with an aftermarket cooler their symptoms went away. Both seemed to imply there was a coating or something in the cooler that broke loose. I've checked and bypassed my cooler, and that doesn't seem to be my problem. However, I didn't really check the hard lines themselves. Something could have worked it's way down the return line. I'm going to pull the return line, and make sure it's clear. If so, I'll pull the valve body, and see where the line goes inside, and make sure there is no blockage there...

that is unless someone has a better idea, or reason I shouldn't.

thanks...

It always bugs me when guys don't come back to update the fix. I'm sorry. I thought I had. I pulled the lines and checked the cooler. It was all clear. Finally dropped the valve body and started looking through it. Found a piece of aluminum fin holding a valve open and a chunk of rubber in the cooler return circuit. After I removed them and reassembled, it ran great until a few months ago.

This time it seemed like it was slipping as I was leaving the house one morning. Managed to get it back home and by that time it would barely move. Let it sit for a few hours, and when I came back it was all back to normal. Drove it down the road and back without issue. The next day it wouldn't move. I checked the fluid. It looked normal, but so high in neutral that I had to assume either filter is blocked (or something in that area), or the pump/seal has gone bad. But considering it was fine after a few hours, then not so later, I'm going to go with another blockage. When you put it in gear it moves a little , and if I give it a little gas it will just barely move forward or back.

It's sat a few months and we've decided now to sell and buy something with a little more towing capacity. Figure I'll drop the pan, see what I can see, if nothing, drop the valve body again. If I don't find anything at all, I'll probably put it up for sale as is, or drop the trans and take it to a shop, then sell.

You have a bad converter.

IT could be something as simple as a plugged filter that allows the trans to start working after drain back flushes the crap out and then quits working when it sucks the carp back up. I bought a duster for next to nothing because it acted this way and with a filter and fluid change it was back to normal.

I thought about convertor at first, but since it slipped, then worked then didn't made me think not. I've never actually had a convertor go bad and wouldn't know the exact symptoms.

I'm still leaning more towards a blockage, filter or otherwise. I did drain a little fluid after starting and running through the gears. Didn't see anything in it.

If you have enough junk to clog a filter, you got more going on inside there! I’m with guitar... I’d be pulling the trans with a pump and converter in the budget.

Btw.... the “check valve” in the outlet line on those trannys only purpose was to prevent converter drain back so customers wouldn’t complain of slow engagement after the vehicle had been sitting an extended period of time. In the days of old the owners manual and service information directed you to start the car in N so the cooler system would charge. I drilled the one out of my 01 47re.

Jeep's running again. Another piece of junk holding a valve open. I keep thinking I need to find a book on these transmission and learn a little more. I have one on GM 3 and 4 speeds. Need to at least read it.

From what I can find online it was the switch valve. Cleaned that out and new fluid and filter. Not sure where it came from.

Time to sell or trade now. We need something bigger.

It was the switch valve. It’s the only valve that can cause the converter not to fill. If it’s doesn’t fill the fluid will show high on the stick and with the converter not full it feels like it is slipping.

Delayed engagement is exactly that - a partially filled converter.

Thanks. Could you recommend any books, websites, etc for learning more about the specific functions each part and circuit?

My suggestion is to read it from the experts - find a Service Manual from Mopar.

If I recall the later manuals from around 2000 have much more detail on the function of each valve along with the overall function of the trans.

Alrighty. Thanks...