intermittent AT light and hard shifting

[pingwin77]

Along with my spark plug issue, Sunday, my "AT" light came on. Once I got home I cycled through the gears to see what was up. It shifter quite hard into Reverse but fine into drive.

I shut the car off and let it sit for a min. I started it back up, the "AT" light went away and it shifted fine. So I figured it was a fluke.

I woke up Monday morning and it was back on again, with the same symptoms. I got to work and let it sit all day, the light went away and it was fine.

This morning the light came on about half way to work and when I went to lunch it was still on.

Any ideas? A buddy of mine said the tranny could be going out but I thought that the issues would be more consistent. could it be a computer issue?

 

[dmention7]

Maybe low transmission fluid?

 

[ZoomZoom Diva]

Low or old transmission fluid could be an issue... A friend of mine had this happen when the transmission fluid got worn out and cooked.

 

[pingwin77]

That's what I was hoping, I looked at the fluid, the level was good and it was dark so the color was hard to see. Rumor has it that the 3's go through tranny fluid rather quick. How ofter should it be replaced? Maybe it is the filter as well?

 

[ZoomZoom Diva]

I'm a believer in changing tranny fluid every 30K. (statement of opinion)

 

[dmention7]

Rumor has it that the 3's go through tranny fluid rather quick.

I've heard this as well. If you're on your original fluid, I'd say it's definitely time for a flush & fill

James' figure of 30k miles sounds like about what I've heard anecdotally about the 3's automatic.

 

[pingwin77]

Yeah, it has been about 40-45k since the last one. Time to get her in. Thanks for all the tips!

 

[DrWebster]

The ATX in the 3, both the 4 and 5 speed, eat fluid for lunch. I'm flushing mine every 25k, and the old stuff still comes out looking like shit. Synthetic fluid is a very good idea for this transmission as well, I'm using Mobil 1 ATF in mine.

 

[pingwin77]

So I drained the fluid, replaced the filter, scrapped about 3/16 of an inch of metal off of the magnet, wiped the pan clean, replaced the gasket, filled then drained a second time.

I'm still having the same issue. Any other ideas of what it could be? I'm also wondering if you know any place that will scan the AT light other than the dealership? Morrie's wants $160 just to scan the light and tell me what is wrong. That's a lot of money right now with my hours being cut at work.

 

[dmention7]

Many auto parts stores will scan codes for free, and many repair shops will also, but charge you for a diagnosis. Pep Boys and Advance Auto are the two that come to mind first.

 

[pingwin77]

I know they do a CEL but they can also do a transmission light?

 

[DrWebster]

I doubt a generic code reader could pull a tranny code.

What I'd do is call up each of the 4 dealers in town and play dumb. Tell them what the symptoms are, then ask how much to diagnose. Pick the lowest cost. $160 is like 2 hours of labor, which isn't nearly how long it takes to hook the laptop up to the car and interrogate the ECM.

 

[pingwin77]

Morrie's in Minnetonka, Walser in Burnsville, Polar.....who is the 4th?

 

[DrWebster]

Luther

 

[pingwin77]

So I figured I would give a quick update since this seemed pretty weird to everyone I talked to.

The father of a guy I work with owns a transmission shop and brought home the code scanner so I could see what the AT light was from. It ended up being a fluid pressure solenoid. Most (if not all) cars run at almost twice the pressure in reverse than in any forward gear, hence the hard shifts into R.

The real funky thing is that electronic things like this are not intermittent. The guy was totally confused so he just cleared the code and told me to call him if it came back on. It has not been back since. The best we can figure is that was some bigger piece or some build up on the solenoid that was preventing it from opening/closing all the way and with the new fluid and filter, it eventually cleaned it all out. :banana::banana:

If for any reason it comes back or something changes, I'll keep you posted but it seems to be fixed so far!

 

[pingwin77]

So the light came back on and all the same symptoms are back. I ran a can of Seafoam Trans Tune into the devil and that seems to be helping.

I was only going to run it for about 10 miles and go get a flush and fill from a buddy that is a manager at Jiffy Lube. When he went to look at my car they could not find any place to hook the machine up to. There are lines for a tranny cooler down there aren't there? If so, does anyone have picture so I can show my friend?