2000 Grand Prix 3800 Part Throttle SURGE trans???

**rschap1** · 08-26-2011, 05:50 AM

I got a 2000 Pontiac Grand Prix that you guys have helped A LOT on, THANKS ! ! !
When the wife used to drive it it was diagnosed as having trans issues.
A couple shops said it needed to be rebuilt w/o even seeing it.
Another shop scanned the computer and said solenoids in the trans were sticking.
Those were replaced and it seemed fine for last 30,000 miles. It has over 180,000 on it now.
We have owned it since new though and had a pretty pamapered life.
But when I drive it now, it seems like it does not drop out of OD like I would expect it to.
If it were an old school carb motor and auto, I would think that was the case, or the lock up convertor was not releasing, but that is my old school likeness...
But when I am trying to accelerate or head up a hill at around 2500 rpms say, the tach will start to stary from 2200 to 2800 and the car kind of lugs and surges. Trying to describe as best I can.
About a year and a half ago I cleaned the mass air sensor, replaced the oxygen sensors, and ended up replacing the cat which fixed the SES light and it has ran realy good until now. If anyone thinks anyone of that is related at all, sorry if not. No light now, just the surging. I just give it a lil' more gas, stand on it harder and it takes off revs a lil' higher and all good.

Appreciate any ideas, known issues, or similar scenarios...THANKS again ! ! !

**bstuby** · 08-26-2011, 06:06 AM

Sounds like torque converter lockup solenoid is messed up. I have a 98 and it does the same thing. Go and check out grandprixforums.net There is a world of info on that site, and almost everyone on there has had that prob with there car.

**rschap1** · 08-26-2011, 06:10 AM

Will do THANKS

**rschap1** · 08-30-2011, 09:31 AM

Well, after reading all of the stuff on GP forums...I am thinking the TCC solenoid may be cause of my symptoms.
I am going to try and short the battery cables to clear codes and see what that does.
Also read that cleaning the MAF sensor. I still have a can of cleaner.
I also have 1/2 can of SeaFoam Trans Medic that I was told may have helped free up the other solenoids that ended up getting replaced about 30,000 miles ago. Back then I dropped the pan, changed fluid and fiter. Magnet had a VERY slight film of fuzz and fluid was still red and nice looking. But code kept showing up. I think that was like a 2-3 shift error. I am not sure if the torque convertor solenoid got replaced back then or not. I have got about 180,000+ miles now. Good except for the surge, fluttering during part throttle acceleration troubles.
I will be checking for vac. leaks around the intake too...
But,
Anything else I might be missing?
Anything to make the trans shop aware of if I gotta go back?
THANKS!!!!!

**cammed goat** · 08-30-2011, 09:56 AM

Well...if and when you replace the solenoid, and the issues go away, the trans shop might not find anything. HOWEVER...you can take the car back to the shop to have a tech look the car over once you complete the job and see if the tech finds anything else.

**rschap1** · 09-02-2011, 09:27 AM

I did the crossing the battery cable/code clearing deal, tossed 1/2 can of TransMedic SeaFoam in there and just about the same if not slightly worse. I am going to dig out my receipt from the trans shop and see if they did the TCC solenoid, give 'em a call, and see about getting it scanned at least. Doesn't sound like there is anything else to try or do w/o dropping the trans....is there?
THANKS AGAIN!

**rschap1** · 09-22-2011, 08:48 AM

The surging keeps getting worse now. Trying to decide what to do now. I pulled out my receipts from the trans shop. Over a year and a half and 50k miles ago. Guess I cannot complain too much since the "band aid" got me that much more use of the car (now @185+k miles). But...
Think I will ask the wife to take it back to the trans shop and ask them to scan it again. They said code # 1811. Their estimate originally said that they found faulty pressure control solenoid which is what I think they replaced in the trans. Also showed MAF not reading properly and recommend replacing sensor and connectors. So ... since I never did anything besides spray the MAF sensor with aerosol cleaner a couple times, that may be totally f'd now and need replacing or the torque convertor control like I had been reading. Gotta believe getting it scanned will tell me more, but thought I would see if there is anything special to ask the trans guys about, have them check specifically for, or "extras" or specifics to look at or repair IF the trans does have to get dropped again. (Being reminded of the MAF sensor has me hoping that is it, of course, but just in case). Appreciate anything I might need to know. Will check in again once the scan happens (I know I am just guessing until then). THANKS as always ! ! !

**rschap1** · 09-22-2011, 08:52 AM

I see as I look closer at my old receipt...part # was 33946 for the pressure control solenoid that got replaced.
Guessing that is different than the one which controls the torque convertor???
If it is, I guess that is why I am sstill fearful the trans needs to come back out again, if the TCC trouble and this are one in the same...maybe I will be lucky (luckier any ways) and focus more on the MAF sensor...

**bstuby** · 09-22-2011, 10:27 AM

Honestly, you got a good life out of the trans. Like I said, I have a 98 that has 199,000 on it (original trans) and I don't have 3rd gear anymore. It's been this way for almost 7 months now I would say. The trans in these cars are not the best. People are usually shocked when I tell them my car still has the original trans in it, seeing how they usually go out at about 150ish. Be lucky you have got this far with it haha.

Not trying to bring you down any, but my car started out the same way yours is now. Except mine would surge and buck in 3rd gear, guess that's why I don't have 3rd gear anymore? I know mine needs replaced, but I'm going to see how far I can make it. It may last another 20,000 miles or it may go out today. I know it will leave me stranded one day but hey, that's what insurance and free towing is for right?

As far as the tcs solenoid, I don't think it's the same as the tcc solenoid. I could be wrong. Your maf could have something to do with it also. Try unplugging it first to see if the car runs any different. If you unplug it and the car still runs the same, then you need a new maf. If it runs like crap when you unplug it then it's fine.
You would know if it was bad right off the bat tho, mine was bad and sitting at idle, the rpm's would bounce between 400 and 1100 rpm.

What did you use to clean it with?

**rschap1** · 09-22-2011, 10:36 AM

The wife bought this car brand new so it has had a relatively easy life. I got it handed down as my daily driver just about a year ago. Mostly highway and ... hhhmmm try to be nice to it. I have tried to keep up on the maintenance since she got it (and I paid for it). As soon as I called trans shops, they all said it was junk and needed rebuild replace right away since the year model it was and miles on it. But so far, pretty good. The trans was replaced just after she got the car under warranty. Maybe there was some upgrade or improvment way back then.
I know that it could be pretty much anything until I get it looked at, but will try the unplugging of the MAF and see what that tells me. THANKS. Autozone or NAPA actually sells a MAR sensor cleaner. I had never heard of it until I sent the wife to buy a new one and the counter person recomended trying it first. Said that they had 50/50 feedback from customers that had tried it, but for a few bucks may as well. I did try a new MAF sensor back then w/o anything getting better.
We'll see...
Thanks

**bstuby** · 09-22-2011, 11:02 AM

Here you go man, This is some good reading for the p1811 code you have. I got this off TEP (Triple Edge Performance) website. This guy is a the 4t65e god haha. Basically, he knows his shit!

Code P1811 is hands down the most common trouble code and commonly asked about problem. This code can set for numorous reasons and often by a failing pressure control, BUT on higher mileage transmissions this is often not the case or at least is not the only cause to the problem. With that said it is important to understand that replacing the pressure control solenoid is NOT a guaranteed fix!

This code will set when the pcm/tcm detects excessively long shift times. For every shift the pcm/tcm watches how long the shift takes to complete in milliseconds. If the shift times are over roughly the .06 second timeframe and the pcm/tcm tries to compensate for this by raising line pressure and still does not see acceptable shift times after a few shift cycle it will trigger code P1811. When this happens it puts the transmission in a max line pressure condition to help protect the transmission against excessive slippage and burnt clutches. While this condition is present you will feel harsh shifts, some vehicles more agressive than others, and you will also hear a whine noise similar to what a power steering pump that is low on fluid will sound like. You can shut the engine off for a brief moment and restart the vehicle and it will feel normal again until a few shift cycles of excessive shift times and the cycle will repeat itself. This typically only happens after you have driven for a short while and the transmission and its fluid warms up.

Some common causes to this problem are-

-Poor working PCS (Pressure Control Solenoid), also called EPC or Force Motor
-Excessive clutch clearances
-Poor functioning accumulator system
-Worn internal seals and sealing rings
-Excessive valve body wear
-Dirty MAF sensor resulting in lower commanded line pressure

Due to the list of potential problems it is difficult to suggest just one or two items to cure code P1811 as everything above and many other parts and variables all play a role in the effect. Unfortunately because of the orientation of this transmission and how it sits in a vehicle it requires quite a bit of labor to access the pressure control solenoid as well as the valve body. One thing popular to try before diving into an expensive and labor enduring repair is to install a shift improver kit such as the Transgo SK4T65E shift kit that we offer. This kit includes a new set of accumulator springs and spacers to limit accumulator piston travel which greatly speeds up the time it takes to apply a clutch, which hand in hand will shorten the shift time. These kits are not made to create firm or harsh feeling shifts but to help speed up shift timing and keep what the pcm/tcm wants to see in check to prevent code P1811 from triggering. As mentioned above higher mileage plays a big role in how this transmission works and also means you should replace parts with caution and have the understanding that there is no 100% guaranteed fix to this problem without tearing into the entire transmission to address and upgrade the problem areas.

**Cutlass** · 09-22-2011, 05:06 PM

I have a feeling the whole surge issue is due to a faulty MAF sensor. Its a pretty common failure on these cars. It can also affect how the trans shifts and behaves.

**bstuby** · 09-22-2011, 05:35 PM

Originally Posted by Cutlass

I have a feeling the whole surge issue is due to a faulty MAF sensor. Its a pretty common failure on these cars. It can also affect how the trans shifts and behaves.

Yes it is, and very expensive to replace.

**rschap1** · 09-23-2011, 09:01 AM

The MAF sensor is easier and cheaper than a trans rebuild though right...?
Or should I should I stop hoping for that?
This weekend I will try the cleaner again, unhooking and seeing if it makes any difference, then go from there.
The trans shop's diagnosis (over a year ago) said to replace the wiring harness(pigtail) too. Is that a common failure?

THANKS again for all the help ! ! !

**rschap1** · 09-23-2011, 09:04 AM

bstuby, what does your car do w/o 3rd gear? still driveable?

**Cutlass** · 09-23-2011, 02:37 PM

Originally Posted by rschap1

The MAF sensor is easier and cheaper than a trans rebuild though right...?
Or should I should I stop hoping for that?
This weekend I will try the cleaner again, unhooking and seeing if it makes any difference, then go from there.
The trans shop's diagnosis (over a year ago) said to replace the wiring harness(pigtail) too. Is that a common failure?

THANKS again for all the help ! ! !

The harness is not common but certainly possible. I think the GM MAF is about $250ish and the are two tamper-proof torx screws holding it on. Double whammy, I know (expensive part and special tool to replace it.)

**bstuby** · 09-23-2011, 08:46 PM

$250

Go to your local auto parts store and get a Cardone for 170ish brand new. If you don't feel like spending that much money, then get a BWD reman one for around $100 plus core charge. Same warranty as the rest of them. I'm sure you already have the T20 bit for the screws since you said you cleaned the maf, so no loss there.

**bstuby** · 09-23-2011, 08:57 PM

Originally Posted by rschap1

bstuby, what does your car do w/o 3rd gear? still driveable?

Yup, drive it 60 miles every day. It goes from 1st,2nd,4th. Kinda annoying at times, I asked around about it and I guess it's not that common of an issue. Said something about it being a sprag issue? But basically my 3rd gear is toast from what I gathered. Which doesn't surprise me since 3rd was slipping for a awhile before it went out.

**rschap1** · 09-26-2011, 09:44 AM

I do have the tamper proof torx bits, hopefully this week I will try the unplug trick, pull the sensor, spray it down with the cleaner, try and get in at the throttle body blade too since it sticks when you first apply accelerator too. If no different, I will trade rides with the wife for a day and ask her to visit the trans shop again for a scan...
Come on MAF sensor (at least I can handle that myself).

THANKS gain for the help(s) ! ! !