'99 "Lurching" on the highway

[davidcarlhill1]

We have a 1999 Grand Am SE 6 cyl...have had for a couple of months; the problem is this:

When on the highway, usually between 40-55 MPH on a very mild incline, the RPM's will bounce back and forth, and you can feel the car lurch back and forth (for lack of a better way to put it)...

Usually, when you give it more gas, the overdrive (I guess) kicks in, and everything returns to normal...however, while on vacation in Tennessee, the check engine light came on after one of the episodes; after arriving at my relative's house, we added A LOT of transmission fluid; there is no leak in the transmission, and the whole reason it was so low probably had something to do with the fact that the guy who sold it to me didn't check it when refurbishing the car to sell (this was a salvage vehicle); as everyone probably knows--no dipstick.

ANYWAY, I had it taken in for error codes to be read, and they said that at one time, the torque convertor solenoid (sp?) had stuck, and that cylinder #4 had misfired three hundred and some times; by now, the check engine light was off (of course)...

Moving on, I changed the spark plugs (they were SHOT), but not the spark plug wires...while the check engine light has not come on, the car has done the "lurch thing" 3-4 times in the last 5 days while going to and from work...

Any ideas?

Oh, and it has around 104,000 miles.

Thanks in advance.

David

[xeroinfinity]

welcome davidcarlhill1 . the surge might be the transmission. Both of my GAs do it alittle. It feels like the over-drive just shifts up and down. I've heard other people comment on it too. Some times just being low on fluid can cause this 'slip-age' feeling. It does suck trying to check the level, the hole No dipstick thing was a Bad idea.

If you're still getting misfire codes I'd change those plugwires. My 99' needed new injectors to make those misfires go away. that was expensive but well worth it. Around $85-90 each. hope this helps.