2004 Buick LeSabre Drivability Issues
After inheriting the 2004 Buick LeSabre (99,730 miles). I noticed a bit of sluggishness, low gas mileage (15 mpg city) and a bit of a rough idle. So I decided to get a tune up. The mechanic changed plugs and wires and done an oil change. (New AC Delco plugs and wires). The next day I noticed a huge change in the cars function, BUT NOT FOR THE BETTER! I drove my daughter to school. Upon my drive home I felt a lag. Next I felt the car begin to stutter, shimmy then surge. This happened approx 4-5 times as I tried to drive home. I prayed I'd make it home! The car never stalled out and no check engine light shown. Next I decided to look for anything loose, worn out or odd under the hood.. Nothing looked odd, but I did locate a couple loose connections. I then secured them. Next day I took the car for a 5 mile drive. The car ran fine. The next day I drove approx 2 miles. I thought I felt what seemed like a delay in the transmission shifting. I stopped at the store for a couple things. Upon my trip home (approx 1/4 mile after leaving store) the car began to stutter, shimmy and then surge (engine temp was still warm). This behavior continued on and off all the way home. *Car never stalled out and no check engine light ever appeared at this point. Next day I decided to let the car idle to see if I could recreate the issue. Once the engine was fully warmed the car once again started to shimmy, stutter and then surge. The car then returned to normal (well the normal slightly rough idle). After approx 5 minutes the car again began to shimmy, stutter and then surge, but this time it stalled out. I decided at this point to leave well enough alone. *No check engine light has come on yet! I took it back to the mechanic.. The mechanic has supposedly checked the spark plugs and wires. They showed no issues. He also supposedly cleaned the MAF. He thinks it could be the MAF or Ignition control module.However, he is totally unsure due no check engine light. He is telling me it's fine to drive (The surging SCARES ME!) The mechanic is hoping I continue to drive the car in hopes the check engine light will come on. As I mentioned I feel it's too unsafe! I am confused why all of this started after a tune. I am also confused as to why the car only carries on when fully warmed. PLEASE point me in the correct direction as to what could be wrong with this car!?!? * Car normal idle is at 1000 rpm. During surge jumps to 1500. After surge with no stall idle dropped to approx 750. Thank you!