1997 Pontiac Transport with 185,000 miles.
I have determined that my Pontiac minivan needs a Sonnax valve body
rebuild kit. Does anyone have access to the GM TSB on Valve Body R&R??
(See below for background info.)
A month or so back, I started getting a 2-3 second squeel that sounded
like a slipping belt that eventually engaged at the end of the 2-3
second squeel. I noticed the power steering was dripping onto the
Serpentine belt and dismissed the problem as a slipping belt. Then on
a subsequent trip down to South Carolina, the Service Engine Soon
(SES) light appeared and the tranmission would no longer lock up the
Autozone found two (2) error codes, both of which were P1870.
After surfing the web last night I found a bunch of info on the P1870
that had to do with slipping Torque Converter Clutch (TCC) problems.
Most of the posts had to do with Chevy Trucks, not minivans. It
appears that GM replaced cast iron their valve body with Aluminum and
suffered loss of wear resistance. Apparently the valve gets worn and
fails to generate proper pressure to the TCC, and causes it to slip.
Last evening I pulled the PowerTrain Control Module (PCM) fuse in
effort to clear the code. This didn't work, but this morning I once
again experienced the 2-3 second squeel as the TCC tried to engage.
I have called the Transmission shop and they are quoting prices from
$800 to $2000. I am about ready to sell the minivan for $2000-2500;
hence, this sort of investment seems foolish.