2001 Limited transmission woes

[airplane69]

For the past two years, my LeSabre has had trouble shifting from first to second in the mornings. Rather than shifting smoothly, the engine revs and I get stuck in intersections, moving slowly. Usually within five minutes of starting, it will slam into gear and the car will buck, but will be fine for the remainder of the day. Back when the car was under warranty, I took it to two different dealerships at least five times and they insisted that there was no problem. The final time, I finally was able to show them (the other times it wouldnt' do it..for a while it wasn't *every* morning) and they claimed to adjust the solenoid and the problem went away for awhile. Then, once the warranty expired the problem came back. I just kept driving, reluctant to take it back. Well, tonight the car bucked hard while driving and fell out of gear. I pushed it to the side, called AAA and they took me to a garage that I do not know.

I'll find out what they say tomorrow, of course. But, in the meantime, I wanted to know if anyone else had had a similar problem and what the problem might be. I searched the forums and couldn't find anything.

[Allbert]

Originally Posted by airplane69

For the past two years, my LeSabre has had trouble shifting from first to second in the mornings. Rather than shifting smoothly, the engine revs and I get stuck in intersections, moving slowly. Usually within five minutes of starting, it will slam into gear and the car will buck, but will be fine for the remainder of the day. Back when the car was under warranty, I took it to two different dealerships at least five times and they insisted that there was no problem. The final time, I finally was able to show them (the other times it wouldnt' do it..for a while it wasn't *every* morning) and they claimed to adjust the solenoid and the problem went away for awhile. Then, once the warranty expired the problem came back. I just kept driving, reluctant to take it back. Well, tonight the car bucked hard while driving and fell out of gear. I pushed it to the side, called AAA and they took me to a garage that I do not know.

I'll find out what they say tomorrow, of course. But, in the meantime, I wanted to know if anyone else had had a similar problem and what the problem might be. I searched the forums and couldn't find anything.

From your symptoms, I'd bet a dollar that you do have an issue with your pressure control solenoid (PCS). If you've had the vehicle in while under warranty for the same symptoms, I'd try to make the dealership replace the part now since they obviously did not fix it before. By the way, there is no "adjustment" that will correct the defect in the Delphi pressure control solenoids... they need to be replaced when they are bad. It's a good bit of labor to get to the part, so having someone else do it could run $500 or $600. The part itself (part number 10478146) is only $29.00 plus shipping from gmpartsdirect.com.

[airplane69]

Thanks for your reply, Allbert.

I found the invoice from that trip to the dealership and I was wrong, they didn't "adjust" the solenoids, but they replaced the 1-2 shift solenoid and the 3-4 shift solenoid. Is this the same thing as the PCS solenoid that you mentioned?

I'm obviously not as knowledgeable as I should be about this stuff and I'm dreading the call from the garage today...

[Allbert]

Originally Posted by airplane69

Thanks for your reply, Allbert.

I found the invoice from that trip to the dealership and I was wrong, they didn't "adjust" the solenoids, but they replaced the 1-2 shift solenoid and the 3-4 shift solenoid. Is this the same thing as the PCS solenoid that you mentioned?

I'm obviously not as knowledgeable as I should be about this stuff and I'm dreading the call from the garage today...

The shift solenoids control which clutches are engaged while the PCS controls the line pressure in the transmission to vary shift firmness and to maintain adequate clutch pressure to prevent slippage after shifts. Flatrater has a really good post over in the Buick Century forum http://www.automotiveforums.com/vbul...ht=pcs+problem that shows pictures of what may be wrong with the solenoid.

To be sure, you're problem could be a number of other things, but considering the level of teardown you or a tranny shop would have to do to diagnose other issues with any certainty, swapping the PCS is a pretty good gamble, especially if you do it yourself. Please come back and let us know what the garage says though.

[Allbert]

One more thing... I think California mandates an extended warranty (up to 50,000 miles and I'm not sure about the time limit) on emissions related components. I'm pretty sure the PCS is considered an emissions related component (check your warranty information to be sure), so even if you're outside the 3/36 warranty period, you may still be covered in CA.

[airplane69]

Originally Posted by Allbert

The shift solenoids control which clutches are engaged while the PCS controls the line pressure in the transmission to vary shift firmness and to maintain adequate clutch pressure to prevent slippage after shifts. Flatrater has a really good post over in the Buick Century forum http://www.automotiveforums.com/vbul...ht=pcs+problem that shows pictures of what may be wrong with the solenoid.

To be sure, you're problem could be a number of other things, but considering the level of teardown you or a tranny shop would have to do to diagnose other issues with any certainty, swapping the PCS is a pretty good gamble, especially if you do it yourself. Please come back and let us know what the garage says though.

Thanks for yr reply. The garage wanted $2200 to rebuild the transmission. So, I promptly got it out of there and had it towed back to the dealership that had switched the shift solenoids previously. The acknowledged the long history of my multiple visits for the problem back while it was under warranty and gave me the impression that they'd work with me to make things right. I will let you know what they say once they've taken a look at it.

[airplane69]

Originally Posted by Allbert

One more thing... I think California mandates an extended warranty (up to 50,000 miles and I'm not sure about the time limit) on emissions related components. I'm pretty sure the PCS is considered an emissions related component (check your warranty information to be sure), so even if you're outside the 3/36 warranty period, you may still be covered in CA.

Interesting, I'll look into this. The car was originally purchased in Iowa, but has been in California for two years now. Would it have to have been purchased here to be covered by the law?

[93buicklesabrelmtd]

Pressure Control Solenoid.
These trannys a very sensitive when it comes to the tranny pressure.
Your 4t65e tranny uses the solenoid to control the vaccum on shifts.
The older 4t60e used a vaccum modulator that was attached on the front of the tranny.

Im almost certain this is your problem.
This is a diffrent solenoid from the shift solenoids.
But why didnt dealership suspect that and replace it at the same time?

[93buicklesabrelmtd]

Once you replace the pressure control solenoid, your tranny should work brand new. It does not need a costly rebuilt!!!
Alot of people like saying to rebuild it, its easy to say.
But why?

And wasnt the new 4t65e designed to fix this very problem?
With vaccum pressure? they introduced the electronic solenoid. Pressure Controled Solenoid. I am very suprised this would happen on a 01.

And it is harder to access that solenoid, cause its not mounted to the front like the vaccum modulator on a 4t60e

[maxwedge]

The way to be sure what is going on here is the use of a bi-directional trans scanner that command and monitor the solenoid functions.

[stuzman]

Originally Posted by maxwedge

The way to be sure what is going on here is the use of a bi-directional trans scanner that command and monitor the solenoid functions.

I agree with you max to be fully sure of what's really going on with the solenoids. Also, a scope could also be used to do the same thing, but a scanner would be easier as far as the hookup.

[93buicklesabrelmtd]

Originally Posted by maxwedge

The way to be sure what is going on here is the use of a bi-directional trans scanner that command and monitor the solenoid functions.

Maxwedge, yes the best way to be positive is to use a Trans Scanner.
But from his problem of what he described, it just sounds like a really bad pressure problem. Any pressure problem will surely mess the shifting up.

[Allbert]

Originally Posted by maxwedge

The way to be sure what is going on here is the use of a bi-directional trans scanner that command and monitor the solenoid functions.

In conjunction with a pressure gage connected to the line pressure tap and a reference to indicate acceptable pressures at commanded currents, it would be possible to verify correct performance of the pump, actuator feed limit valve, pressure control solenoid (PCS), torque signal (TS) valve, boost valve, and pressure regulator valve with a trans scanner. If any of these components are not functioning properly, then (as far as I know) it is necessary to diagnose the individual valve body components either by disassembly and inspection/bench testing or replacement with a known good component. If a line pressure problem were detected, I would bet that most transmission shops and dealerships would probably replace the PCS before doing any other work unless other issues were clearly indicated (like metal chunks in the oil pan or noises from the pump indicating obvious mechanical damage).