Transmission acting weird !!! HELP !!!

[Slidster]

I have a strange problem with my transmission... Hopefully someone can help me to solve it...

I'm driving a Firebird 1999 with a 3.8L V-6

The transmission runs normally most of the time but after driving for a while it will sudenly change gears somewhat roughly mostly between 1st and 2nd gear... When it does that, all I have to do to stop it from doing it is stop the engine for about 30 seconds and restart the car and everything is back to normal...

The weirdest part is that it's not doing it all the time...
Very confusing, isn't it???

Does anybody have any idea what's goin on with that?
Please, Let me know !!!

Thanx !

[84fiero123]

sounds like u might have a blocked cooling line or trans cooler or just plain shit in the lines that is causing it to get hot. when was the last time u changed the fluid and filter, something most people never do. but then again its a lot newer than most everything im used to

[Slidster]

Originally Posted by 84fiero123

sounds like u might have a blocked cooling line or trans cooler or just plain shit in the lines that is causing it to get hot. when was the last time u changed the fluid and filter, something most people never do. but then again its a lot newer than most everything im used to

Thanx for the reply but I had the fluid changed not too long ago and even after changing the fluid it was still doing the same thing...

[GTP Dad]

Check the solenoid that changes the gears from first to second. You could have one going bad the other possibility is the vacuum modulator. They sometimes cause similar problems when they are going bad. They are not expensive and can be replaced very easily with simple tools.

[Slidster]

Originally Posted by GTP Dad

Check the solenoid that changes the gears from first to second. You could have one going bad the other possibility is the vacuum modulator. They sometimes cause similar problems when they are going bad. They are not expensive and can be replaced very easily with simple tools.

Thanx GTP... that something i will definitely check...

Another thing happened yesterday on my way back home from north Florida... I was driving on the highway and then the RPM was going up to 4000rpm while I was only driving at 65mph...
I stopped to check the fluid level but it was fine...
somehting weird is going on here...
I hope I won't have to replace the transmission