The old winter car 98 Lesabre has been acting up recently. Monday when a few miles from home it started going between gears upshifting and downshifting and giving a decent clunk when starting from a dead stop, Checked the Trany fluid level and it was not low, A bit over full. It sat in the yard for maybe an hour, and I took it for a ride, It worked perfect. Tuesday it worked fine till 10 miles from home and did the same thing. I went slow and made it home No problem. When this happens the cruise control never works. Today the transmission worked well, the cruise did go out for a short time then started to work again.
I had auto zone check for codes and nothing came up but a map sensor because the manifold intake upper has some minor damage causing the sensor to not read perfectly. it idles a bit rough but runs fine past idle. I should just change the intake manifold. It’s not a hard job and is cheap. But that would not be causing the tranny issues. So far, its only done this after running for maybe 30 minutes.
If its the servos inside the tranny I will not be fixing it. I am considering changing the tranny fluid and filter which is easy and cheap. But how likely is that to help?
The transmission pressure control solenoid may fail causing erratic shifting. Our technicians tell us that partial dis-assembly of the transmission is necessary to replace a failed pressure control solenoid.
Affected Model Years
This issue affects Buick LeSabre model years 1991, 1993, 1994, 1995, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005