97 Buick Le Sabre problem automatic transmission

[Guest]

97 Buick LeSabre with 57500 miles. auto transmission seems to search for correct gear between overdrive and fourth (i believe it is 4th) while under load going up hills. it "hunts", "stumbles" and searches for correct gear to stay in. if i can get a long enough run at a hill such as on a freeway - no problem. but if i am in hilly country where there is no opportunity for long run the trans will not stay in 4th or overdrive. trans has developed a whine which it never had before. any ideas out there as to what needs to be done to correct this? the engine checks out as not having a miss (new plugs, air filter) and i have the car up to 90 (one time only) on level freeway, recently

to see if the problem would show up and the trans did not do the "stumble" etc.

[86 2dr.ltd]

We live in the hills. Have a 86 LeSabre with the four speed overdrive tranny and a 97 Olds LSS (same basic car as yours) with the updated version of the FWD 4sp overdrive tranny. We do not use overdrive but leave it in D around home. The overdrive is no good in the hills its to high of a gear , but its an automatic so it tries to shift up then realizes its no good so it down shifts. Its that simple. You will also get better gas milage in drive (D) around town or in the hills.

Just to check it out - be in high gear (OD) going up a slight grade.

Hold the gas pedal steady and pull the shifter down one click into D notice the car will actually speed up, and you will be able to let off a little. Check out the manual shifting of the lever while sitting in you driveway before you do it while driving (in case you have never done it) if you pull it down into 2nd or 1st accidently while doing 55 you may take some life out of your tranny or engine. Just one notch into D.

OD is for flatlanders and highway cruisin'.

Its a 4 speed tranny 1 - 2 - D - OD .

[86 2dr.ltd]

Also if you have long steep hills like we do here D will help on the brakes going down hill also. I dont know how your car is but the LSS will get up to 70-75 just coasting down our hills in OD . It takes much riding of the brakes to keep it close to legal so atleast D keeps it down to 60-65 without to much braking.

[NTX5467]

Just by chance, have you had the transmission fluid and filter changed lately? If not, it might be advisable as that whine could be a pump wanting more fluid flow.

The Buick V-6 is very torquey at lower rpm levels, but there's not enough there to lug that car with several people up a hill at 40mph in OD and it not first unlock the lock-up torque converter and then grab a downshift to the next lower gear. If you try to run that route with the cruise control on, it'll really be doing that stuff. The current LeSabres, in OD, for example, take 80mph to get to 2000rpm on the tach on the level roads.

You might also check with the dealer to see if there are some updates they can "flash" into the computer to possibly help what's going on, but the best advice would be (as stated) to just put it in "D" and not "OD" when you are in the hills.

An engine that runs at a little higher rpms (and stays up on the torque curve in so doing) under less load will probably get better mpg than one that's lugging around under higher load at lower speeds. It will take less throttle to let the engine run in "D" and therefore keep the computer from putting more fuel into the engine also. Everything will be much happier that way and the transmission will see less wear and tear also. Same with non-fuel injected and non-computered cars with OD transmissions too.

Just some additional thoughts,

NTX5467