Car won't shift until i let go of gas

[bogitto]

The car has been acting wierd lately. The car sometimes wont shift until i let go of gas. Sometimes i feel a slight jerk when it would shift.

There was one instance that it jerked real bad and there was a loud thud after driving it for about 400 miles. I parked it for 30 mins I was supposed to have it checked but it went away.

Maybe you guys have exeperienced this before. By the way mine is an 03 alero 3.4 GL automatic

thanks

[jawa]

check your fluid level

[spc2125]

Possible trans slipping?

Automatic I assume

[zzyzzx]

Did you check for codes?
How many miles are on the car?
Check your TPS.

[bogitto]

no codes, no check engine light, 178k miles

[MilzyZ34]

stock pcm?

any access to real-time data logger or good scanner?

[Nas Escobar]

I think I know what you're talking about... It shifts hard when you let off the pedal and it feels as if it was a stick and it was being driven by someone who can't shift.

I get this sometimes, and the "trac off" light turns on and can't be turned off.

I think it's computer related. It goes away when I restart the car. That's why It went away for you after letting it sit for 30 mins. I'm really thinking it's the computer.

Does it always do it, or is it sporadically?

[bogitto]

got the car fixed and fortunately its not the transmission, it is still good according to the mechanic, i had it flushed and replaced gasket and filter anyway since there is a leak around the gasket.... the real culprit is actually the cat converter....

thanks to all who gave their inputs

[bogitto]

by the way other issues that i encountered

- the car won't go past 60 mph
- the car works fine if it hasn't warmed up yet
- there's a leak in the exhaust manifold gasket

[fisdad]

If it happens again, have your local GM dealer re flash the pcm. Mine had some craziness going on after cold starts with hesitation and my tranny felt like it had a bit of a slip in it before I had this done. It was $89.00 and solved my problems.