29th Oct 2007, 21:30

Here is another notch in Buick's gun! I have a 2001 Le Sabre - 43,000 miles and the transmission problem is as described in this string of complaints. At just over 38,000 miles it started the intermittent hard shifting. My mechanic replaced a loose front motor mount and changed trany fluid and filter. This made no difference. The hard shift problem does not start right away; but after everything warms up, then it happens. Turn the car off and let it set 3 to 5 minutes and the problem is gone for a little while. Glad to hear that this is an annoyance. I'm surprised that GM has not done something about this issue.

31st Oct 2007, 12:59

I bought my fathers 2000 Buick Century 4 years ago with 19k miles on it and immediately started having troubles with it.

First the intake manifold gasket went out at a cost of about $1,100

Next thing the blower fan motor will only work on high or not at all, and the knob to turn it off and on broke off.

I am also getting a very weird response when opening and closing the back windows, kind of works when it wants to, and from what I am reading it sounds like the power window motor is going?

Now at 80k I am too getting the hard shift and whinny sound from the transmission, and almost to the T on what every other post is saying it only happens when the motor warms up, I too just shut the car off for a few seconds and restart and all works well for a while.

I did talk to a transmission mechanic and he to said that it is a solenoid that was bad and suggested getting it replaced at a cost of about $700.00. He recomended getting it fixed as the whinning sound is the transmission working way to hard and eventually will cause damage?

Have not had the other electrical problems that some posters have had, but do not think I am going to hang on to the car too much longer to find out.

Good luck to all! I too will "never buy another GM product"

11th Dec 2007, 15:11

December 11 2007.

I too have a Buick Century 2000 with the same problems. It was good till about 80000 km when my solenoid went. I had it repaired at a qualified trans shop for a fee of 600.00 Cd.

A year later it started to shift hard if I would step on it a little, especially on a little incline (the hard shift would shake the whole car). I took it back to the same trans shop, who then put it on his computer and gave me a quote of 2000 to 2500.00 to fix it. I have a personal friend in Edmonton who has a 30 years of trans experience. In my frustration I hadn't observed the code that he requested.

Now what he told me might help some of you. Without knowing the code or spending 2500.00, try this. He explained (unquote) your trans is somewhat computer controlled, and your pump's pressure runs between 60 to 80 pounds. If your oil is a little low, the computer will program it to around 140 pounds, thus the hard shift. He suggested add 2 litres of oil to your transmission (he said it won't hurt it even if it shows overfull, I only did 1) and disconnect the positive battery cable for about 2-5 minutes. That will program your computer back to zero and should fix your problem. I did what he told me to do, and I've drove about 5000 km now, and no trouble.

9th Jan 2008, 11:28

I had the intermittent transmission problem with my 2000 Century starting at about 80,000 miles or so. Same symptoms, drive the car for a while and starts to hard shift. If I shut it off for a few it stops the problem for a bit. I went to have it looked at back in April 2007 at Amoco (I will never go back there) - they didn't even really do any in depth diagnostics, just said I needed a new tranny or a rebuild. I took it to a local place that specializes in transmissions and they knew all about the PCS valve problem, ran a bunch of tests and determined that was the problem. They told me they had an upgrade kit for the PCS Valve assembly so once they fixed it (900.00 later) it shouldn't be an issue... Fast forward to a couple of days ago and lo and behold SAME issue again! I called the place I had it fixed and they need to look it over again... The guy did tell me that the computer will try to compensate for the tranny when it senses trouble, but at some point the computer 'can't keep up anymore' which is why the problem happens after a long period of driving and then goes away after re-starting the car.

I'll re-post after I've had it looked at and let you know what they came up with. More than 1k and I'm ditching the car.

11th Feb 2008, 07:20

I too have a 2000 Buick century - bought it two days ago with full knowledge of the shifting problem... this is what I've found-out so far...

http://www.automotiveforums.com/vbulletin/showpost.php?p=3500495&postcount=7

I will keep you all updated. Past Centuries I've bought have performed extremely well. The car I have now has very low miles, and was serviced well.

11th Feb 2008, 08:32

http://www.automotiveforums.com/vbulletin/showthread.php?t=398499

I've added this link to give everyone an idea what a GMC certified mechanic is looking at when he replaces a bad PCV solenoid. These pictures and the accompanying text show clearly the problem and why it occurs. If you go for the fix, please ask them to replace the solenoid with a non-Delphi compatible solenoid. All Delphi PCV solenoids #10478146 are considered defective, and the supply chain is full of this part for various cars and years.

This is the technical memo distributed to all GMC transmission shops. It's a bit heady, but you all get the picture:

http://ww2.justanswer.com/uploads/jettadan1/2010-12-01_163622_tranny.pdf

11th Feb 2008, 14:29

Same problem here. I have a 2000 Century with about 52,000 miles on it. Car shifts hard after 20-30 minutes of driving. Seems to be better in cold weather. As I recall, the problem started when the car hit about 30,000 miles. I've had two mechanics look at it and both said that nothing appeared to be wrong with the transmission. Neither could figure out what the problem was.

I've resigned myself to just continue driving it until the wheels fall off and then put the thing in a junk yard. No sense spending $2,500 to realize (as many of you have experienced) that the repairs did no good.

Lesson learned. No more Buicks for me.

12th Feb 2008, 07:06

THERE IS HOPE!!!

Don't fret because this will be the last entry I make regarding the century 4T65-E transmission on this site. I have entered two of the past three comments, and I've found the sure fire cure!

As I stated earlier, it doesn't pay to have a faulty part put into your already ailing transmission. There is an alternative:

http://www.tripleedgeperformance.com/New_Home_Page.html

This site lists the Pressure Control Solenoid for the 4T65E, made by a company called Borg Warner (force motor) and is considered worthy of high performance racing. It retails for $47.95, and can be purchased at the above mentioned site. Take it to your mechanic, or if you are mechanically inclined, install it yourself, if you are serious about fixing the problem.

Good luck!

This should conclude this thread for all time.