Hello.I just found this forum and hope somebody might be able to give me an informed opinion of a problem I am having with my 1999 bonneville ssei with 182,000 miles.The transmission is slipping completely, however if the car is turned off, and started again immediatley, it drives just fine for a couple of blocks then slips again, could this be an electrical or control problem, or is the tranny most likely just shot. thanks for any help. Marc

When was the last time the transmission was serviced?

Is the trans fluid at the correct level?

Does the transmission make any noise after it starts slipping?

I would start with changing the fluid and filter.

Hi Marc...

The trans is toast. If you change the fluid and filter, it will run for a while, but not for long.

FWIW Steve (SGP) is a transmission rebuilder with years of experience. Sorry to say the diagnosis doesn't sound good.

Might be a good idea to check the line pressure. If you have good pressure, the trans is going out. If you have low pressure, it could be a simple clogged filter. However, it could also be a blown channel plate gasket. I just did a swap on a car that had one of those. It drove but slipped, sometimes it would not slip. Pull the dip stick and check the trans oil level, if it'* really high on the stick, that could be the problem.

Just remember 1 thing, filters only clog when there is trash floating around, which usually means something is coming apart.