Hi All,

About six months ago, the Lesabre wasn't coming off the line well. It was like it wasn't grabbing first gear to get going but then once it got going, was normal. I checked the fluid level, it was about 1.5 pints down, so I added that amount. I checked the stick and no improvement on the level even after about 1 hour of waiting in a completely warm engine.

Next day, wife drove it to work and said it was fine. I checked when warm the next day and the level was at the exact same level, no movement at all even after adding almost 1 quart. That is weird, I have never seen that before. Car ran normal until now, 4 and half months later. By the way, never saw any leaks, maybe its real slow? I thought for sure the unit was fried but it shifted great for months like the original condition never happened.

Fast forward to last Sunday. Same condition started, same level on the stick. Car would barely move at all coming off the line then once it going, same as usual, all normal. I added fluid like the last time along with Lucas fluid. It got a little better, but not much. By Wednesday, I had added about 4 pints out of a 12 pint capacity plus the Lucas. By Thursday and Friday, there was a marked difference. It was getting off the line almost as normal but not quite. I noticed that if I started off in gear one or two, start off was completely normal. Maybe I don't have a first gear? What is also weird is that the condition has gotten significantly better since last Sunday. Its about 70 percent normal.


So tonight, I checked the stick and I actually got a reading. It was not one pint low. So I added the pint when warm. No noticeable difference but I'm wondering if tomorrow it will be normal as it seems to lag over a day or so.

I'd start by checking the vacuum modulator for a leak, most-specifically leaking transmission fluid through from the hydraulic side to the vacuum side. Start by pulling the vacuum line off of it and see if there'* transmission fluid in it.

You may have had a burp which it took up. If it'* still low add whatever.

In all honesty, I have always had trouble getting a fluid level read on these transmissions. Every one of mine has been happy showing considerably overfilled. My low fluid symptoms usually began as odd shifting behavior, especially on a downshift to 1st at 25mph, and slipping as I turned while accelerating.

Has the transmission been serviced? What is the history, and what work has been done in this area? How many miles?

As CathedralCub said, pull the vacuum line from the modulator to check for leaks. Also look elsewhere for significant transmission leaks as well, especially at the transmission cooler lines, as those will likely be significantly aged if original, and likely leaking.

1992 Buick Lesabre with 137 000 miles. We bought it seven years ago from original owner with 41000 miles. Has been fantastic. Still had the original brake rotor as of last year which I changed along with calipers. Doing first tuneup now, still has original ac compressor and just about everything else as well. No leaks at cooler lines, original transmission gasket never changed. Engine and trans never touched other than battery, changed hoses, and serpentine. Wife drives it over 14000 miles per year, no rust and looks very good. So much for Toyota, how comes no one talks about these?

They do. The problem is a lot of them died early, and often due to stupid stuff, and often the stupid broken stuff was expensive to fix. This was right after two decades of quality control issues and corporate shenanigans testing stuff on consumers. Meanwhile, Buick television commercials had that same guy telling us to "See your Buick dealer TODAY!" while Toyota/Honda/Nissan made us want to buy their exciting cars for less money instead. That being said, yours and many Buicks of the era were purchased by older folks, treated nicely, driven little, and maintained well, such that a few lucky folks can come across one that'* in great shape like yours. I'd challenge you to find a same-year Bonneville in as good of condition.

My $0.02 .

I get what you're saying but I think these cars are so well made and ill put that up against any japanese car which many in my family own. I believe in these where as in 2000 I wasn't so sure. I also have a 2000 Park Avenue and can tell from a guy with amateur racing experience, that although I wouldn't call it a fast car, it drives excellent. The chassis is rigid, brake balance excellent. I get behind the wheel of this boat and push it to the limit and its there with me, I still can't believe it years later.

There is a 1997 Motorweek review of a Park Avenue and they were shocked how they drive. Watch the review on Youtube, its not just me. So yes i agree with you, i found a great preserve one but preserved or not, these cars were made so well from the get go and they last. People I know that haven't been exposed to these and take a ride are very surprised. I'm glad you know this but Im telling you, a lot of people don't know.

I think a lot of it has a lot to do with luck and maintenance.

Luck: How well was the car was built in the first place.

Luck: How well did the design modifications of older parts for newer cars actually work?

Luck: How well was it repaired when it had problems.

Maintenance: If it got maintained well, it would last a long time. A lot of the ferrin' cars could put up with lower maintenance from the start. A lot of them caused `murican manufacturers to start trying longer intervals and less maintenance.

If the transmission has never been touched, then it is definitely overdue for a service. Every 30k miles the pan is supposed to be dropped and filter changed. When done, the standing recommendation is to refill with Dexron VI fluid.

My Park Ave still has the original Transmission. I normally go to GM & buy their gasket & filter kit.
Maintenance schedule for me is every 50K with the Dex6, so far so good.
Definitely inspect for leaks & fix what ever is needed. The pan gaskets can leak pretty good too if not been changed in a while.
Check your owners manual under capacities & specifications. My ole Pk Ave requires 11 quarts so the manual states, and definitely use DEX 6.
I normally let it drain for an hour, & add about 6.5 quarts, take a reading and then drive with a small funnel handy, stopping frequently, adding a bit at a time until it'* at the hot/full line.
Check hot in park, on level ground, after driving 20 minutes or more.