[ZTR23]

I have a 2001 Automatic GT. So today I was getting on the freeway with the A/C on and I had to punch it just a little to get on before a semi. After I was able to get into the slow lane at about 70mph, I let off the gas. Just then I noticed the car "surge" and it felt almost as though I were braking, but I wasn't. The RPM pin decreased when this happened as well... I thought it might have just been a fluke, so I switched lanes and brought it back up to approximately 70mph again and let off the gas... Same result, but this time it was two quarter second pulses with the same "braking" sensation. Anyway, I got to my destination and let the car cool off for a bit. About 30 minutes later I got back in the car and went back home. I figured I'd do a little testing on the way home. When getting on the freeway, I turned off the A/C this time, punched it at about the same speed, got up to about 65 mph and let off... Same thing happened, but not as sever. I continued to drive it the next 20 miles by bringing it up to 70, 60, 65, and 55mph and letting off, but nothing happened after that.

From what I've read, some say that the air filter might need to be changed? (as far as I know, it's the stock filter and I have a K&N ready to be dropped in)

I'm kinda concerned as it might be a transmission problem, but who am I to know.

Thanks for any and all responses. :nervous

 

[jjandascog]

Could be your IAC, what do the RPM's do when this is happening?

 

[ZTR23]

Well from what I could see (I was was too busy worrying about throttle control on the freeway and not stalling), the RPM's went from about 2000 or so down to about 1500 or so when it surged... I'm pretty sure it was trying to shift down from the O/D setting to standard 4th, and that's when it started surging. But it also did it the first time I was on while driving and casually going up to 65 and letting off.

 

[wmburns]

Sure sounds like the lock up torque converter isn't releasing. What's the level and condition of the fluid?

 

[ZTR23]

I'm gonna take it out for a freeway spin tomorrow... It also revs a bit different with the A/C on... pretty sure that's normal though. I'm HOPING it was just a fluke in the fuel lines or something. Or stuck in 3rd and was engine braking.