Thread: Please Help!

Hello Everyone! Well here i am with my 1999 Pontiac Grand Prix GTP with something in the transmission acting up. Problem first started after the installation of headers and 3" exhaust on the vehicle. Just to note, plugs, wires, coil packs, TPS, MAF, MAP sensors were swapped. I even swapped a newer blower with yet newer sensors on it around a month and a half ago. I installed the exhaust earlier this year, i would say early march. Now for the issue... The transmission shifts throughout all gears as it should, smoothly and accurately, except for overdrive, fourth gear, whatever you refer to it as. Say for instance, ill be driving 45MPH and when you ease off the throttle once you reach your speed, the transmission shifts in to fourth or overdrive. Now once this occurs, whenever there is a hill or slight to minor throttle increase (load on engine), it seems as though the transmission fights to engage/disengage to compromise for the load. As you will see in the video, it sort of surges. When you see the RPMs jump and stay at 2500, i put the transmission into 3rd, once it drops again, i put it back into drive. This car is my daily driver and of course i don't let the transmission do this to the best of my ability. (I would accelerate enough to completely drop fourth and get up to speed, then let off, after all that's why we have BOOST!) I understand that in fourth, the the TCC (torque converter clutch solenoid) is responsible for the direct drive from engine to transmission hence no torque converter engagement. I also understand that my transmission may have a EPC solenoid, and or a PWM solenoid. I am unsure of their full responsibility in the transmission, although one most likely is a pressure control solenoid to some extent. Anyhow, i recently did a pan drop/service on my transmission. The fluid was in very good condition i must say and didn't see any problems until i found that piece of plastic in the bottom of the pan. I have absolutely no idea where this may have come from or its purpose, however it clearly broke off of something. Somebody that works with these transmissions may know what it is part of. Overall, i am posting this because i want to figure out if it is the torque converter itself, or the solenoids controlling it. The problem has not gotten any worse since its appearance. I know this is a book of a post, but thanks for reading and i am looking forward hearing what you all have to say.



VIDEO
http://www.youtube.com/watch?v=T-CGZ...ature=youtu.be


Picture of plastic piece (sharpie cap for size comparison)

IMAG0004.jpg

Looks like torque converter clutch slipping, see if you tap the brake pedal while keeping the gas steady if it jumps up a couple hundred rpm and the surge goes away. Usually I end up replacing the converter for this, and as a failsafe, I usually replace the TCC PWM and Pressure control (EPC) solenoids in the side cover (valvebody). The converter clutch failed in my GTP and the clutch came apart, and clogged the filter so I would loose all gears after a minute or 2 of running. Not sure about that plastic piece is from, hard to identify from the pic, could be small piece of the pressure switch or something. there are not too many plastic parts in our transmissions aside from the filter, the pressure switch on the vb a couple of lube shields and some thrust washers.. so not too sure on that one. Thats just my 2cents.

IT is part of the converter. It is possible that it is just the solenoid, but usually once they start slipping they have a tendency to glaze like overheated brakes and won't stop slipping even if you corrected the problem. That said, you could try either a good quality transmission flush or perhaps one of the additives on the market to try and help but no guarantees. Hard to say for certain without having a scanner on it watching TCC slip speed etc. HTH

Mine I never really had the slipping thing so I think when they come apart that may start as a different thing. I know a few that have lived with it for quite a while. Prob. best in your case to try lucas or one of the other better known additives and just keep driving it. Save your $ for a new ride.