Transmission Problems

[diablo5969]

Just before you get started reading: I must warn you this turned out to be a long post. But if you think you can help me diagnose a problem, I'd greatly encourage you to read it

I'm experiencing transmission problems (I think) with the Ex, and it's kind of worrying me.

Yesterday when I went out to lunch, the Ex started acting weirdly. Whenever it was in gear (reverse or overdrive, but not park) and I did not have my foot on the gas pedal (like at a traffic light or sitting in traffic), the Ex starts to jerk back and forth. It starts out as just a gentle rocking, but if I sit for long enough it will actually start jerking. The reason I originally thought it was the tranny was because the first thing I thought of when I felt it was that it feels like when you're driving a manual and you don't get the right combination of clutch/gas and it starts jerking.

At first I didn't think it was too big a deal, and I just thought I'd get it looked at whenever I got the chance. But then yesterday after school I was sitting in traffic driving to soccer practice, and the Ex stalled on me. That's when it became a more major thing for me.

After school I stopped by Peachtree Ford, and they said they wouldn't even get an opportunity to look at the Ex for 3-5 days. From there I went to Aamco, who also wouldn't look at it without me either dropping it off or missing school. Neither of which are viable solutions.

Tomorrow morning I'm going to try and take it out to Billy Howell Ford and have them look at it. I was just wondering if anyone here could help me get an idea of what the problem is.

Here are the details:

• When not accelerating, the Ex rocks back and forth. It starts as a gentle rocking, but progresses to a violent jerking.
• When it is doing that, the battery guage is going ballistic. It moves in coordination with the rocking/jerking.
• The headlights also dim and come back, following the battery guage.
• Though the battery guage is effecting the headlights, it doesn't affect the stereo.
• The engine/transmission/underworkings of vehicle is making an odd noise, also in sync with the rocking.
• As I mentioned earlier, it only rocks in gear, not in park. Originally I tried putting it in park at the traffic lights so it wouldn't rock, but the Ex put up a fight and didn't want to be put in park.
• The Ex stalled on me yesterday afternoon, but hasn't stalled since.
• While it's rocking, the RPMs are going from about 700 to about 1200, surging in sync with the rocking.

Original predictions from friends was that the transmission fluid was low, so I checked that, and that's fine.

I'm out of ideas.

If anyone has any suggestions for what could be ailing my transmission?

Just some background on the Ex:
It's a '94 with an automatic transmission with 92,000 miles on it. As far as I know it's had no major work done on it, and I'm not positive if the previous owner was exactly on top of maintenance.

I know this has been a long post, and anyone who's read this far, I must thank you. However, if you could give me some suggestions about what's going on with my transmission (or other drivetrain component if I've wrongly diagnosed it), I would thank you even more

EDIT: I added more symptoms as I remembered them

 

[92KENNEY]

one question do you have a system in your vehicle and id just like to say off the record -you have a BEAUTIFUL pos FORD tranny, dont get me wrong im a ford driver all the way but the next time my x's tranny bites the dust im either getting a new x or putting in a 350turbo tranny by chevrolet

 

[Opera House]

I doubt its your tranny

Sounds like a sticking IAC, loose or cracked air tube going to the throttle body, loose tube on the vacuum tree or manifold leak. The tranny is doing what it is supposed to do, go into gear when the engine rpm's increase. IAC and computer are probably doing what they are supposed to do, compensate for fuel mixture and regulate speed. So you get this rocking. If the engine rpm had dropped, then it could have been the tranny. Try searching around with a rubber hose to your ear to find the sound of an air leak. Wiggle air tube. Clean IAC.

 

[diablo5969]

Wait a sec, I don't get that.

If the RPMs increase, it's not the tranny. But if the RPMs decrease, it is the tranny?

I'm getting both, the RPMs are just surging between about 700 to about 1200, so the RPMs are both increasing and decreasing.

Also, 92Kenney, I wouldn't say that I have a system, per se, but I got a new head unit, new speakers, and a new sub, with new amps and soundproofing on the way. All the stuff's in my sig

 

[Opera House]

I should have stated

That if the engine rpm dropped from 800 to 500 then there could be a problem wit the torque converter clutch coming on and loading down the engine. Never heard of this exact problem, usually it happens when coming to a stop and the clutch does not disengage and the engine stalls. The problem you are having is the same as sitting in gear at idle with one foot on the brake and the other foot pulsing the gas. This will torque the vehicle and cause it to rock. The torque converter has a normal slip speed but as the speed increases it will produce more and more torque. Your problem is something is causing the engine to speed up.

 

[92KENNEY]

ok im not sure on the trans i'll leave that to opera but your lights blinking/fading of your lights goes with the bass of your stereo if so you have s bit too much power draining on your starter and the fading will stop if you use higher rpm's and work your starter a little more

 

[diablo5969]

That was the suggestion my dad had when he drove the Ex, maybe the clutch wasn't disengaging properly. But as I said, it stalled on Thursday afternoon, but hasn't stalled since.

So you think the clutch might be having issues now?

Kenney, I know the fading headlights aren't from the system. When the Ex is rocking, the battery guage is surging along with the rocking, and the lights fade with the battery guage. It's all related somehow.

 

[Opera House]

I missed some of that

I had a problem with my 92 years ago. I was stopped waiting for traffic when the car suddenly surged. I thought my foot slipped on the gas. Then it happened again. Had to make a stop before I went home and when I tried to restart the vehicle, it wouldn't start. Popped the hood and found the battery connector had cracked. When it made an intermitant connection, it reset the computer. The computer then thought that you were starting the car and it opened the IAC valve wide open, causing engine to surge. Remove and clean battery connections. While battery disconnected loosen nuts on starter solenoid on fender and retighten. This is where they redistribute power on my 97. Could be the same on yours. Your problem could be a bad electrical connection.

 

[diablo5969]

It doesn't seem like we're talking about exactly the same thing. But I'll check that out next time I'm outside, thanks!

 

[TDG]

All of this and no CEL? That's weird. Does your CEL work? I would think that anything that is so out of whack that it's causing this much of a problem should throw a code if it's an engine sensor problem.

Like Opera House has been saying it could be a problem with the IAC or an electrical issue which may not throw a code.

Just for speculation, what if the pump in the transmission was failing to maintain adequate pressure at idle? If this were the case I could see the RPM surging up as the EEC thinks the vehicle is in drive and is compensating for the extra load that suddenly isn't there. In this case when the engine RPM comes up it may be enough to build up pressure again and it grabs dropping the engine RPM only to repeat the process.

From what I've seen so far on the 1st gen explorers the transmission is pretty much a separate entity off on it's own. The EEC doesn't really have any way to tell if something is wrong with it since the only sensor that I've found is the one that tells the EEC what gear you've manually selected. This explains why there can be transmission trouble and no CEL.

Sorry that I don't have a better answer, just speculation.

Tim

 

[diablo5969]

The CEL has been tripped in the past, so I assume that it works. When you initially turn the car on, and all the guages light up for a second, it lights up.

I don't like the sound of the theory of the pump in the transmission failing to maintain adequate pressure. It sounds like a pretty big deal. Hopefully it's something smaller.

My mind is drawing a blank at the moment, so time to ask an incredibly stupid question: What exactly is the IAC again?

 

[diablo5969]

Ahhh, thank you. I even got a picture, that's very professional.

So are there any things I can do to it to either A) give it a quick fix or B) find out for sure whether or not it's the IAC?

 

[TDG]

I took the picture down to help save bandwidth since you've already seen it.

You can clean the IAC, I forget how but there are a ton of threads on the subject and it's pretty simple from what I remember.

The whole transmission thing I came up with was more of a "could this happen?" type of thing.

 

[diablo5969]

Wow, you are being very professional with the picture, now taking it down.

Alright, I found one of the threads about cleaning the IAC: Dead Link Removed.

I'll try and clean it and see if the situation improves. Unfortunately, I probably won't get a chance to do it for another couple days though. But we'll see what happens when I do.

Thanks for all the help so far!

 

[TDG]

Originally posted by diablo5969
Wow, you are being very professional with the picture, now taking it down.

I helped get a thread closed yesterday so now I'm on my good behavior.

 

[diablo5969]

Ewwww, how did you pull that off?

 

[TDG]

It was a combination of things, probably others more than me but it got closed right after my post.

 

[diablo5969]

Now I want to read it

Can you post a link?

 

[TDG]

It's a little off the topic for here. But you have mail. And your PM box is full.

 

[Jason_25]

Chase, what's the condition of the fluid?

How long since it's been changed?

The torque converter clutch in mine messes up sometimes when coming to a stop, but not while just sitting still. When stopping, the idle will fall down really low around 400-500 and rock a little bit, and occasionally it will stall. I guess this could happen at a standstill too.

If this is the case, I beleive the tranny will need to be rebuilt to fix it.