Help! Slipping In/Out of Torque Conv. Lockup

[Eric]

For level set, it's a 98 A4 with 68K on it. The problem occurs more when the fluid is still pretty cold, under 100 degrees, but still occurs with less severity at normal operating temps. I had the filter replaced and a flush performed with Mobil1 trans fluid but the problem persists.

After the car shifts into fourth and I hit cruising speed it feels as though it drops in and out of lockup for a couple of seconds then it seems to fins its place and is fine. The times when it doesn't do the in/out thing, it just feels like it slams into lockup instead of the smooth operation it should be.

Any ideas what is causing this? I have pulled codes and nothing powertrain related shows up at all. Could low fluid level cause this? If so, how do I actually check the level? I know I have to remove the plug with the car running, but how do I know what the proper fill level is?;help

Thanks,

 

[c5y2k]

Eric, not sure I can offer any help the the diagnostic work but I can with the fluid level check.

A big thanks to Hib for this. I have had this bookmarked for just this sort of thing.

http://www.idavette.net/hib/C5diy/c5diy2.htm

 

[DRTH VTR]

Eric-
I have no idea whether this could apply to you or not, but this was what I experienced with my '97 A4.

It would also come in and out of lock, or not lock up at all. One day, I noticed that when I pulled up on the brake pedal, the torque converter would lock up. It makes sense, as the lock-up is released when you step on the brakes. Somebody adjusted the switch that is activated by application of the brakes, and the problem was solved.

 

[Eric]

Thanks Jim and Shan!

Being one who has never been fond of being under a running car, even with all six jack stands and steel wheels underneath, I think I'll see if Jim's brake pedal issue is at fault. Then maybe I'll make my wife nervous by crawling under the car while it's running:eek.

Ain't this place the best! (rhetorical question, we all know the answer)

-Eric

 

[c4c5specialist]

HI there,
Just remember, the vehicle does NOT look at vehicle speed to determine shift points.
It looks at rpm of the output shaft itself.
So, that being said, MAP, MAF, temperature all can have a bearing on this.
Tech 2 data should be the next course of action here.
If you want to take a drive, Eric, come by and see me.
Id be happy to nail down a diagnosis for a cup of coffee!!!
Allthebest, c4c5