tbill,
You are getting some very good advice on this board from many people regarding your Malibu. Nobody has addressed your fuel economy issues, so I’ll try.
If your fuel economy is going down, check the simple things first like your tire pressure, air filter, spark plugs and wires.
The next culprit is usually your oxygen sensors. You have newer car, so you have 2 of them. One ahead of the catalytic convertor, and one after. Nowadays they are usually heated and last about 100,000 kms. After that, the fouling from various gases starts to slowly decrease their ability to measure the O2 content of the exhaust gases and you may notice your fuel economy ever so slowly decreasing. Then one day, you discover you have lousy fuel economy.
If you have an O2 sensor that is really gone, you can perform a simple check by using a paperclip to jump the A and B connector of the Assembly Line diagnostic Link port.
If it is slowly on it’s way out, you will have to get hold of an on board diagnostic computer and check your crosscounts and compare your Block Learn Mode values to your Integrator values. You should see your crosscounts fluctuating wildly, and your Int value should be 128, or close to it, and your BLM should be trying its best to match the Int value of 128.
The next on my list of things to check would be the Exhaust Gas Recirculation valve. Unfortunately, on new cars, this is also computer controlled, so you will have to get a computer to check it as well. The General Motors dealership or a good independent garage should have a Tech II computer that can open and close the valves individually to see if they work, and check when they do open to see if it works properly.
As far as your other concerns go, most people have provided good answers, so I’ll be brief on my opinions.
Front brakes on most FWD cars are crap. Don’t turn rotors, just throw them out. The longer a pad lasts, the harder they are, so the longer stopping distance you will have. I use Raybestos pads and rotors. Changing brakes on FWD GM cars is easy. All you need is a T55 socket, big C clamp and a hammer. Email me if you want to know the details.
Rear drums on FWD cars should last well over 100,000 kms. I would turn drums once.
Rear disks on FWD cars last about the same length of time as front disks, sometimes they go first. Don’t know why.
To check the squeak in your dash, pull the cosmetic covers off underneath your dash and see if there is anything there rattling around. Unfortunately, squeaks and rattles in new cars are common. In fact they are the biggest source of complaints from Honda and Toyota owners, so buying a different car may not help you.
I change my oil every 3 months regardless of mileage since moisture builds up in the oil from sitting and short trips where the oil doesn’t get a chance to heat up. Also, I’ve got a bad memory, so I pick a quarter of a year because it is easy to remember. Can you go longer, sure, but I choose not to because as far as I’m concerned, Toronto driving is hard miles.
I rotate tires. I find they last longer.
Don’t forget to change your transmission fluid. Your trans is the most complicated component in your car, so don’t neglet it.
Finally,
Find a good independent mechanic for your non warranty work.