This is my 1999 Bonneville SE with 114,000 miles. I've had it about 3 weeks now and have replaced the thermostat because it was stuck open and only would hit about 150 on the temp gauge. Replaced the air filter and the fuel filter which was a replacement and not the original. I have a new Gator belt, AC Delco plugs and wires to replace still. Also fixed the nasty rust holes in the right rear wheel well. Also found that my rear bumper reinforcement tube is really rusted out.
I was going to replace it with a straight tube, but decided to just drive the car for the cheap transportation that it was bought for.
So now that it has gotten cold out, and I replaced my thermostat, I expected a nice hot ride in to work. But that isn't the case. It only blows mildly warm air and it seriously takes 30 minutes of driving before it feels warm in the cabin. Plus my temp gauge on the dash seems like it fluctuates alot between about 195 and down to like 160? I don't think it gets down to like 150 where the needle stayed before I replaced the thermostat. It does seem to rise back up to 195 fairly quickly after it was down to about 160. I'm guessing the heater core is bad? When I replaced the thermostat, I syphined out about a gallon and a half of coolant and it was fairly pink/orange still, so I'm guessing that it has had the coolant replaced because it isn't a nasty brown color. I thought about flushing the radiator, but would like to just flush it after/while replacing the intake manifold gaskets which I know I should have done pretty soon..... just finding the money to do it though.... The previous owner who had the car for 6 1/2 yrs and had it since it had 32,000 miles did not have the UIM and LIM gaskets replaced, so I'm assuming they are still originals.
It still feels like the motor bogs/hesitates when I am making a turn, either while moving or from a stop sign. Maybe a bad wire grounding out while turning the car? Sometimes I think that the tranny just isn't kicking down? From a stop going straight it runs fine and shifts fine.
Thanks for any input.