My Matrix (65,000 miles) had been starting a little rough at times but otherwise running fine. when I took it for my routine oil change, I mentioned this to my car guys. They said it could be several things which may be indicative of a more serious problem down the road. It was down almost a quart of oil since last oil change and after checking for leaks, etc. printed off material about possible oil consumption problems in the Matrix. Apparently, some of the 2009 models are sometimes doing this and I went to the dealer and they performed an ECM reprogramming procedure. I’ve been reading that this doesn’t always help. Anyone with knowledge or experience on this?
According to that TSB if the car has over 60,000 miles or is using less than one quart of oil in 1200 miles Toyota will not do the fix under warranty.
The OP say it used “almost a quart” over an oil change interval of presumably over 1200 miles, so this car fails both of the above criteria.
Toyota says it’s a 14.5 hour job to replace the pistons and essentially rebuild the bottom half of the engine.
I don’t think this problem is worth fixing out-of-pocket; the rough running may just be a matter of replacing dirty spark plugs or running a bottle of Chevron Techron in the gas tank.
I’m well aware that OP’s car doesn’t qualify for any “warranty” work, because of the age/mileage
However, it’s helpful to have an idea of what may be going on
As you said, it’s an extensive repair that may not be worth doing
My last car had bad rings, and it wasn’t worth repairing it. It was easier to just add oil as needed
Need to know the actual oil consumption, in quarts per 1000 miles to make an assessment. All cars use some oil. Except if a warranty applies, anything less than one quart per thousand miles is probably not worth worrying about, other than monitoring the consumption rate to see if it is getting higher. Newer cars are tending to use more oil, due to newer technology used to reduce weight, etc, and to lower viscosity oil used to improve mpg. You car may be using more oil than did cars 10 years ago, but it may never get significantly worse than it is now. Don’t assume the worst I guess is what I’m saying.