95 Ga Transmission Trouble

I have a 95 Grand Am 3100 engine w 150,000 on it. It would start out in second gear and shift to third fine but wouldn't go into overdrive.

I drove it about 40 miles sped up to 80mph and it finally went into overdrive. I got off the freeway and it went into first and acted fine. After work on the way home it started out in first gear but upon acclerating it would rev up to 3 to 4 grand before shifting out of first gear.

The next day I changed the fluid and filter, the vacum modulator, and the vehicle speed sensor. Took it for a drive and no change. It starts out in first ok but doesn't want to shift out of first unless I lift off the gas (pedal not floored either). If i lift off the gas at say 3 grand and let it shift then get back on the gas it downshifts back to first and then shifts again to second or third depending on how fast it's going.

If I'm going say 40 and maat the gas it will downshift but it doesn't catch a gear and the motor will redline if you let it.

Thanx for the help.

How did the fluid look when you replaced it?

The fluid looked good , didn't smell bad and there was no debris in pan just some grease / graphite looking stuff.

Maybe your trans is just starting to go. The clutches inside could be sticking? a plugged valve or passage way?

one guy told me I have a bad shift solenoid but there's no room to get the cover off without dropping the tranny

We own a Hyundai Sonata it broke down a few years ago and had to replace the car because the transmission wouldn't shift, well we found out from a friend who is a mechanic that the place that was servicing it put engine oil in the transmission by error, is this fixable, what kind of problems could it cause and would they cause permanent damage to the transmission?

It wouldn't cost to much to find out if your doing it yourself, you might have to change the fluid a couple of times to get the motor oil out.

Your best bet is to get it scanned for trans codes,
which if thiers any trans trouble codes stored it would probly say what the problem is.

Though it does sound like a shift solinoid,
but thiers a hundred things that could be wrong.

And darmissino, if thiers oil in the trany, its junk!
It'll need totally disassembled and new clutches will probly be needed.
They'll soak up the oil and be ruined.

A bad SS won't make it slip.

It's not slipping , it's not shifting properly. The stealership wants 90.00 bucks to hook it up. Have you ever heard of a car that you can't get codes from yourself ? It's an obd 1 type but has only 3 pins in it. Autozone says only the dealer can check it. I've tried the paper clip thing but nothing flashes.

These years 94-95 are complicate as they are a hybrid ODB. It was between ODB I and ODB II.

If 90$ is what it takes to find out, it may be worth knowing.
That is a typical dealer price on diagnostics.

That is if its a full diagnostic test with a report givin to you,
then $90 is better then second guessing whats wrong and throwing money at the car.

Good Luck