98 3.8L Transmission concerns

[JenCel]

Hi. I had my tranny rebuilt one month ago after the transmission stuck in first gear and would only go into 1st, park and reverse. A new torque converter was put on as well. Last week the tranny was clunking into second after revving up a little and the rest of the gears were fine. The tranny has been fine for the 2.5 weeks I had the van back. I noticed some resisitance in going uphill or on grades at lower speeds as well.

Then it progressively got worse with the clunking and when I would put it into drive from park it will sometimes clunk and make the van shake. It was starting to rev up near 4K RPMs on the freeway at 45 mph and not going into the next gear, I noticed then the first time the O/D light flashing. I pulled off at the next exit and proceeded to the transmission shop where it was done. When driving I noticed my RPMs were very high and when slowing down to stop at the lights my RPMs and MPH were equally dropping. When accelerating my RPMs were again too high and I was very slowing gaining speed. Going 3K, 3.5K and 25, then 27, then 30 mps until it would go into the next gear at a clunk. I get to the shop and he runs a computer check and some things like the door sensor came up, and the idle air control system malfunction but nothing with the transmission. He drove it and said it was fine but it was sluggish getting to 2nd. So I was to bring it back if it happened again. I go about my business and when trying to get on the freeway on the graded onramp it is revving up again and not picking up much speed and then it finally goes and the light comes on but it is finally shifting somewhat normal.

I get home and hear a lot of clicking that was unusual, I check the engine smell burning something, look underneath and there is an oil that is splattered and leaked all over the frame and such, it is pink when blotted. I get the van towed back to that shop and the line was leaking, they fixed it, and "a" sensor was out and they replaced that. Unfortunately I forgot to ask which one. Test drove it said it was good. I go to get my new IAC valve, and it is doing the exact same thing!!! I get the stuff to clean my valve and to make a new gasket and take it back to the shop and took the mechanic with me to show him what is happening and he thinks it might be the wiring harness. They got an unspecified error and they are going to have me bring it back in tomorrow morning to have the dealer guy come out and test what is going on from the engine to the tranny.

Now I have noticed in my driving it this weekend (they said it was okay to drive to do the things I need to do--I have 3 kids and one is a baby and this is our only vehicle) that the O/D light is off, and the CEL came back on after cleaning and replacing my old IAC valve (which was all it needed as my rough idle and surge has stopped) but I know the door sensor is sending a code, that it will do the revving not going into gear then clunking into gear, that the light will then start flashing but it will run smoother and better. Not always but a huge huge difference in how it runs when I have to stop my van and then start it back up with it reset. Does this sound like an electrical issue, or could it be the VSS, TSP? I asked the guy at autozone about the TSP and he said it wouldn't do all that to my transmission.

Also in case this means anything, when I start the van and leave it in park the idle is up at 900/1,000 RPMs, then after about 5 minutes it will settle back down to 750. In drive it is at 750 but in park it goes up higher again. Any thoughts on this?

Thank you so much for any insight or thoughts or knowledge!

[wiswind]

Lots of issues!
I do know that the TPS can cause an issue with the transmission shifting.....I once forgot to plug it back in....van ran just fine.....but would not kick down when I romped on the accelerator. Of course this lit the CEL....as I had no signal from the TPS.

There is a Transmission Range Sensor (TRS) switch....also known as a "Neutral" switch. This senses what gear you have selected. This is known to fail.....as well as issues with the wiring harness (heat, fluid dripping on the connector, etc).

How long you drove....on how low of fluid...when it leaked? I would guess that the shop topped off the fluid.....so that should be correct now. One step that FORD has a TSB out on....that you should mention to the shop.... When the tranny is replaced or rebuilt.....you need to backflush the transmission fluid cooler that is part of the radiator assembly. When a transmission fails.....often bits and pieces of stuff get into the fluid....and lodge in the small passages in the cooler....which restrict the flow of fluid through the cooler. Also....the contaminated fluid in the cooler and lines....can contaminate the new fluid. If the cooler cannot deliver the correct flow....failure of the new or rebuilt tranny is likely. If the correct flow cannot be restored by the backflushing....then replacement of the radiator assembly needs to be done. I seem to remember that the correct flow rate of fluid through the cooler lines (as measured after the fluid flows out of the cooler, and before it re-enters the tranny) is 1/2 quart in about 30 seconds....with the engine at IDLE, and the transmission in NEUTRAL.

[JenCel]

I drove it for about 30 minutes total with leaking fluid, thank goodness. When I dabbed the fluid it was light pink so they thought that there was water in the line but when they went and inspected everything they found that that wasn't the case.

It is interesting because the tranny is really screwy and then when it finally malfunctions enough times the light goes on and it starts working nicely. There seems to be something going on that it is running okay in "safe mode" but not in regular operating conditions. I do have to give it a bit more gas I noticed and yes I do have some issues with trying to get power for quick accelerations or grades and it doesn't always downshift. It did before but not now. I will mention tomorrow about the flush and see if they are aware. Any others thoughts??

Thanks for responding