98 Transmission Problem

Hi all, I have a 98 buick regal ls, with the 3.8L V6. I am having a problem with the trans shifting from 1st to 2nd after the trans warms up( most of the time it is ok when cold) also has enough fluid. It will shutter and not go in as smooth as it should seems like it slips a little. It only has 58,000mi on it. I have been doing trans fluid changes at 30k intervals. Just recently i put Lubrication Engineers trans all 1150 fluid in so i wouldn't have to change the fluid til 100k, it was fine for a few months and all of a sudden it started to have this problem. I talked to my mechanic and he said, it might be the pressure control solenoid, or the valve body. Just wondering what you guys have to say about my problem, and what trans is in the car the 4T65E or the 4T60E? Thanks

The easiest way to tell whether you have a 4T65E or 4T60E tranny is by looking at the SPID label located on the back of the trunk lid. Look for RPO code M15 for 4T65E or M13 for 4T60E. The '98 model could have either depending on what month it was produced. In '99 Buick went to the 4T65E in all LS models with RPO code MN3. The Regal GS from '97 to '04 has the RPO MN7 4T65E-HD.

High probability you have a flaky PCS solenoid but to tell for sure get it scanned with a trans capable scanner and see if DTC P1811 is stored. This DTC does not trigger a SES light.

If I had the 4T60E tranny then do they have the same problems too with the PCS?

If I had the 4T60E tranny then do they have the same problems too with the PCS?

The 4T60E could have problems with the PCS since it has one. But it is less of an issue compared to the 4T65E problems. Shift firmness and line pressure on the 4T60E is controlled by a vacuum modulator whereas on the 4T65E by the PCM module.

I checked on the trunk lid and I have the 4T65E tranny, so i guess it will be the PCS. I was wondering can the valve body have the same effect on the tranny?

I checked on the trunk lid and I have the 4T65E tranny, so i guess it will be the PCS. I was wondering can the valve body have the same effect on the tranny?

The PCS is part of the valve body. It is located on the left hand side of the valve body. If a scan reveals P1811 then I would put money on the PCS.

I agree with Bob ^

i would also agree that the pressure control solenoid is your problem. but make sure the torque signal valve in the valve body( the valve behind the pc solenoid) is not sticking. with the solenoid removed for the body stick your finger in the bore and stroke the valve. if it fells scrathy then the valve body should be replaced also of you are in for more of the same problems