I also had a 99 Seville that used oil at the time we bought it at a rate of about two quarts per oil change (3000 miles).
Cadillac said that was normal for the Northstar!!:eek:
Then it got worse,,, down to between 600 and 700 miles for two quarts.
On one trip of about 300 miles we used four quarts !!!
They, Cadillac, said that it was covered under the extended warranty for a engine rebuild but I had to do a carbon flush first saying that the rings gather carbon and get stuck which causes the oil use and this will cure it.
Well they did a double dose carbon flush which helped at first ,bu then within the next oil change (3000 miles) the oil use went back to the 6-700 mile range.
When I went back to Cadillac to get a rebuild they said due to the number of Northstars needing this rebuild the insurance company will no longer pay for an engine rebuild.
They said it was due to engine wear !!!
Screw them !! Adding oil was way cheaper then the $4000+ to rebuild the engine.
I later found out that GM hyad an update rebuild kit for the Northstar that used an updated ring set !!!
This should have been a recall or a class action law suit !!
I waited a long time to get a late model classy car only to be dissapointed in the engine !!
Like I said though,, I think most new cars are about equal in quality through the different models,,,
Stuff like this though causes the bad feeling people get for car makers,,,dq