The wife came home in her Neon the other day and the tranny was acting crazy. I checked the fluid and pulled off the cooler hose to make sure the pump was pumping. It had been about 5K miles and just under a year since my last fluid and filter change and it didn't smell burned. It gave me about 5 different codes; all transmission related. Went to the junkyard the next day and found a wrecked Neon, assuming it was running when it crashed, I pulled the solenoid pack and put it on my car. I went out for a drive and for a while it was ok, but then it started acting up again. It started making a whining noise, and it was like it would engage and disengage. Checked codes and got all the same codes again. After reading some threads on here and other places, I convinced myself I would have to pull the tranny and rebuild it. I was pissed, because the car only has 81K miles on it and I've taken good care of it since it was new. I decided for the hell of it I would try changing the fluid and filter before I pulled it. I put in a new filter and Valvoline ATF+4 and strangely enough the tranny has been working normally since then. It's really weird, but I'm not complaining. One thing I'm curious about is the fluid. Last time I changed it, I used Super Tech ATF+4 from Walmart because it is ridiculously cheaper than any other place. I have no reason to suspect the fluid, but I don't think I'll use it anymore. I'm curious if anybody else has had any experience with it?

 

I've been using Super Tech ATF+4 in a 41TE trans with no problems.

Any issue with the speed sensors can cause weird problems, sometimes overtime metal shavings can get stuck to the speed sensors because they have a magnet in them.

Putting an inline filter is a very good idea to help prevent problems.

This is the filter I use

 

Well, my luck didn't hold out for long. After the wife drove the car quite a bit, Tranny problems started again last night. Put the car in gear and nothing happens. Makes a whining sound. Sometimes it would engage, move a few feet then disengage. Almost like it's low on fluid, but it's not. Now I'm at a loss whether to look towards the TCM or something mechanical inside. Pulled codes this morning. P0871, P0733, P0736, P0732, P0846. Any suggestions or ideas would be greatly appreciated.

 

Maybe check the wiring between the TCM and solenoid pack.

Also the TCM relay, if it has one. And the Transmission ground strap / cable.

And did you check or replace the input speed sensor? It threads in right above the solenoid pack.

 

I'll check those items tonight. The speed sensors were the next thing I was planning on checking after you mentioned it, until I thought it was fixed after the fluid change. Not sure if it has a relay or not. Have to research that more.

 

Went out this evening, disconnected the battery, swapped both speed sensors with ones I got from the junkyard. Disconnected all electrical connectors on the trans and ECM/TCM, cleaned and reconnected. Checked all wiring and grounds. All look good. Hooked the battery back up, started it up and right away it started whining. Put it in gear and after a few seconds it finally engaged. So, basically no change. I decided to check the pump again. Disconnected the hose to the cooler. Hooked up a hose and ran it into a container. By the time I started the car, looked underneath at the container and shut it off, it pumped out probably close to a quart of fluid, so I assume the pump is ok. Here's the weird part. After hooking the hose back up, I started the car to back it off the ramps. There was no whining and it went into gear as soon as I shifted it. Intermittant problems suck!

 

Well, you can go ahead and install an inline filter like the one in the above link.

It should have one anyway, maybe there's something circulating that the filter would catch.

Or maybe the solenoid pack is intermittently getting clogged up, sometimes used ones can be bad too. If all else fails try a new solenoid pack on ebay.

 

I still haven't figured it out. Checked flow through the cooler and it was good. I think I'm leaning toward somehting failing inside the trans, so I'm probably going to drop it and rebuild. I was hoping it was something electrical, but from everything I've read it should go into limp mode if it was and it doesn't do that. I found an awesome trans diagnostic manual on the web that has connector pin outs and everything, but it's only for the 03-05 models.