Follow the exhaust pipe on the passenger side. The modulator is a metal can located above the oil pan, right next to the exhaust pipe on the passenger side. To open it, you need to reach over the exhaust pipe with a 10mm wrench and open one bolt there. Then the retaining clip would come out and the modulator can be pulled off. Just pull it straight out since there is nothing but an O-ring seal. Be extra careful with the small black steel pin that most likely will come out with the modulator. You have to reuse that pin, so don't lose it. All in all, I'd say a half hour job, really easy, except for NOT losing that pin

 

Thanks for the information! I'm going to try and work on it tomorrow by first taking off the vacuum line to see if there is any tranny fluid.

Is there a secret to NOT losing the pin? haha.. I've read so much about that darn pin!

I have all the symptoms of a bad valve......

Shawn

 

Ok... Here is the data thus far..

In the morning after the car sat overnight, the fluid level was extremely high.. Drove the van for 30 minutes and let it idle for another 2 before I checked it again. There was nothing on the dipstick.. I had to add 1 quart before it was where it should be.

Symptoms are... In the morning the car I put the car in reverse and back up. I shift to drive and there is nothing there. Give it some gas and it finally comes in. The next 20 minutes it will shift very odd, sometimes giving the same neutral feeling.. It will act this way when I turn as well as well. After 30 minutes of driving it is back to normal.

The car doesn't leak any fluid and that is what brought me to this post.

It pings or something under load and I have always noticed some stains on the rear door after a few thousand miles. It also has a slight rough idle unless I give it ~50-100 rpm (guessing)

It sure sounds like I have some symptoms of low fluid combined with this modulator thingi.. I went to autozone today and looked at one.. It looks fairly simple. The one at autozone looked to have a screw you can turn to adjust it. I didn't, however, see a place where the infamous pin might go?

Thanks for reading and if you want to pitch in, let me know.. I plan to change this modulator valve this sat... I just don't know which one to get.. The Napa Gold, Carquest or Autozone!

 

Napa Gold gets my vote

there should be a hole in one end - pin goes in there but sticks out

 

You could have a vaccum leak too. That would affect the idle and maybe the pinging too.

 

I thought of that too... I'm hoping it's one of the lines near this modulator or the vacuum distribution.. Other then that, it will be hard to find!

 

Update:

After filling the mysteriously dissapearing fluid yesterday, I had zero problems this morning.. I am 100% confident that it is the vacuum modulator since I have no leaks!

I'll report back on Saturday after I replace it... Feel free to add suggestions if you want

 

One clue is that while mine was doing this it never went low on oil.
At 220K miles you would expect some oil use, mine stayed full way past the "3 months or 30K miles". Before it started it was using a quart between oil changes. The trans fluid added to the oil didn't seem to do any harm, but I'm happier now keeping all the right fluids where they belong