3 vehicles with bad PCS!

this kind of sucks, my intrigue, my dads van and my friends gran prix all have the p1811 and harsh shifting once fully warmed up. All three cars have the 4t65E trans. My intrigue seems to be the worst and will noticably slip on take off unless I pull the shifter down to manual 1...then no slip (this started happenig very suddently so its not a worn trans). I pretty much am broke so theres no way im paying $1000 to fix a bad pcs on a car with 200k miles. I was talking to my neighbour with who drives a buick with the same transmission and he had the same problem for almost a year (slipping/shuddering/then eventually harsh shifting due to MAX line pressure being commanded). He ordered some sea-foam trans tune and said within a few hours it started to shift smoother and eventually his issues dissapeared. Anybody have any success stories? it seems this stuff is a powerful sludge/grime remover and will clean out hung up solenoids etc...I was thinking of running this stuff for a few weeks and then dropping the fluid out of the pan and re-fill. Is the stuff safe? do you have to change the fluid after you add it? whats the difference between this and lubegard?

Lubegard is just an ATF conditioner where Seafoam actually cleans it out. However, on most Seafoam applications the problem will return sooner or later so it is not the miracle cure all.

See the thread below and I suggest trying the fix. Could save you a lot of money. Your choice.

Click here (http://www.automotiveforums.com/vbulletin/showthread.php?t=899929)

Lubegard is just an ATF conditioner where Seafoam actually cleans it out. However, on most Seafoam applications the problem will return sooner or later so it is not the miracle cure all.

See the thread below and I suggest trying the fix. Could save you a lot of money. Your choice.

Click here (http://www.automotiveforums.com/vbulletin/showthread.php?t=899929)


hey thanks for the reply...so i guess i have a few questions


Can I add sea-foam, run for a few weeks and just drain the fluid or would i have to do the filter as well?...do you think the lubegard conditioner could have a similar outcome or does this stuff seem to be the best at freeing up a PCS?

I would use the Seafoam. It is up to you whether to replace the screen filter but personally I would replace it. After running the Seafoam through for any extended period of time this is what you will probably have in the pan. :eek:

http://i5.photobucket.com/albums/y186/lizzywiz/DSC00001-1.jpg

so if I dump some sea-foam into the trans, is it ok to run for a few weeks, and then just change the fluid by dropping the pan or would I have to get it all out with a flush?

With your mileage I would be very reluctant to get a flush whether a power or fluid exchange service like at the lube places. You won't get what ATF is left in the torque converter with a pan drop. ATF capacity is around 10 quarts. On a pan drop if you let it sit long enough gravity dripping you should be able to get about 7.5 qts out. So that will be approximately 75% old ATF.

so im gonna hope 75% is enough...:rofl:....what bugs me is the lack of history on this trans. When i got it the fluid was changed, very recently...because the pan was leaking (bolts not tight enough) and the fluid was like new. for all i know somebody went in there and overhauled the trans (i wish anyway :grinyes:) I personally cant see pulling almost 200k miles on the original trans? from my experience the 4th gear hub lasts TOPS 150k miles

Don't say that! I'm at 162k miles.

That fluid looks pretty nasty. But I do notice that you dont seem to have many shavings on your magnet, I had a good layer of what I assumed to be clutch material on mine when I changed it around 100k. But I dont know if it had ever been changed before.

I cant remember what year the hardened 4th gear shafts started showing up, I think it was '01, so some years should have better luck in that area.

Im starting to rub elbows with 160k and havent had any trans issues, of course lately ive been driving like Grandma Moses to try and cut back on some costs. Which means I only go WOT about twice a day haha.

Don't say that! I'm at 162k miles.


my fourth gear still works, although it does flare up before shifting into 4th (im gonna hope that's another side effect of a bad pressure control solenoid) But I realized the car likes to shift into 4th once i hit 80 km/h (which is the speed limit on most out of town highways, 100 km/h on major divided highways) so it kind of rides at the spot where it likes to shift in and out of 4th gear (slowing down a bit for traffic and re-accelerating) so I just drive in 3rd gear unless im doing a long haul on the highway...2k rpm vs 1400 rpm not too bad, I actually found i get better gas mileage because the engine isnt always lugging.

The bottom end of 4th gear is pretty gutless, I know what you mean by that spot, theres a few roads around here where I have to drop into 3rd as well.

What really sucks, is when you nail it to pass someone, and expect to drop into 2nd and sail around them, but it puts you at the bottom end of 3rd....not so good for the sailing. Im not sure what speed that happens at, between 60-65 for me I think.

This may seem a little simplistic but I've noticed that many of the PCS issues happen after driving for a while (warmed up). Could an external transmission cooler aid in this area? Maybe there isn't enough heat disbursement with our engine bays and radiator setups? I too have a 01 Intrigue and noticed this happen a few times. I've had the transmission fluid and filter changed at 97K and all looked really good. I also read in a thread somewhere that adding about a 1/2 quart more of ATF will help with this issue. Not sure how accurate that is. Just my .02 worth.

This may seem a little simplistic but I've noticed that many of the PCS issues happen after driving for a while (warmed up). Could an external transmission cooler aid in this area? Maybe there isn't enough heat disbursement with our engine bays and radiator setups? I too have a 01 Intrigue and noticed this happen a few times. I've had the transmission fluid and filter changed at 97K and all looked really good. I also read in a thread somewhere that adding about a 1/2 quart more of ATF will help with this issue. Not sure how accurate that is. Just my .02 worth.

Im doing a cooler, for this exact reason. The sea-foam has been in my trans for a few days and seems to be helping. My transmission is 100% perfect when its cold in the morning, but give it 10-15 minutes when the temp hits the 1/2 point is when the sluggish shifting/shuddering and slipping start up. Im thinking a cooler will keep the trans temp down enough to avoid these issues. Another problem with the factory trans cooler is the fact it gets as hot as the engine antifreeze regardless of airflow, I think if you got rid of the factory cooler all together and went with an AUX cooler it would solve alot of problems....Just cut the lines with a saws-all, clamp metal hoses and run the cooler.

I wouldn't bypass the cooler in the radiator myself. I beleive it is not only there to cool the transmission, but to help heat it up as well, especially in colder climates. I do agree on adding an aux. cooler though, especially when it is hot out and especially if you are going to be towing.

I would say adding an additional one is a good place to start. It just seems funny to me that most of the issues start to happen when things get heated up. I'd like to see the long term results of this and if it helps. I'm going to go out and get one and start doing some testing.

I bought my 01 Intrigue in March when it was cold out and never had an issue. I've had the transmission fluid and filter changed before the scheduled 100k maintenance. I've got 97K on it now and noticed that after the first few hot days my trans starting shifting wierd (just like the TB's say). If I shut the car off for a few seconds the problem goes away. The problem is only intermittent.

Maybe the answer is as simple as keeping the fluid cooler?

Also, another thing we could try is adding a switch that allows us to turn on the cooling fans. I've got a 95 Bonneville SSEi that I've added a Aux fan over ride switch and that moves the heat out when I'm in standing traffic.

ooooh me want an SSEi, wanna trade?

But, the Casper's fan override kit for the GP,Regal, etc has successfully worked on one car here that I know of, a member named Rolm installed one, but I believe he has a 3.8, so Im not sure if the fan setup is different or not. I know the radiator, etc is so the fans very well may be.

I would say adding an additional one is a good place to start. It just seems funny to me that most of the issues start to happen when things get heated up. I'd like to see the long term results of this and if it helps. I'm going to go out and get one and start doing some testing.

I bought my 01 Intrigue in March when it was cold out and never had an issue. I've had the transmission fluid and filter changed before the scheduled 100k maintenance. I've got 97K on it now and noticed that after the first few hot days my trans starting shifting wierd (just like the TB's say). If I shut the car off for a few seconds the problem goes away. The problem is only intermittent.

Maybe the answer is as simple as keeping the fluid cooler?

Also, another thing we could try is adding a switch that allows us to turn on the cooling fans. I've got a 95 Bonneville SSEi that I've added a Aux fan over ride switch and that moves the heat out when I'm in standing traffic.

I think what happens is the PCS changes characteristics when heated up, whether the thinner fluid affects it or the actual PCS expands slightly like all things do in the heat, I dont know. What i do know is if my temp gauge never broke the 1/3 point my transmission would always shift perfectly...problem is most intrigues like to break the 1/2 point when sitting and it takes forever to cool back down (turning it off for 5 minutes seems to make it get hotter!) I see a nice spot down in front of the rad to get a cooler mounted, so I think I am going to do it as well. Should be able to get a cooler kit for $50...just a universal oil cooler. Comes with rubber hose, clamps etc. just cut one of the trans lines going into the rad, route it down through the new cooler, than back up to the other side of the cut line. Couple more quarts of fluid (plus the fluid lost from cutting the line) and your good to go. Saws-all should work ok for those lines...if not a pipe cutter should suffice...


The entire problem is basically the transmission doesnt have enough pressure to keep the shift points accurate, and if the pressure falls too low it will slip (like mine)..once the computer sees a few shifts that are outside the set paramiters, it will max out the line pressure so the trans wont slip and destroy itself. This essentially fixes the issue, but your left with very hard shifting and pump whining sometimes..and it resets after you turn the car off. So even though the PCS may still be faulty, if its only faulty in the hot conditions, cool it down and the problem should be much less noticable.