QuestionThis car has 87,000 miles on it and I am using oil. There are no leaks on top,or on bottom, does not smoke, no oil burning smell, but is using a quart between 750/1000 miles, closer to the 750 mark. It also seems to lose power after driving for a hour or so. I appreciate your time and help.
Thanks,
Chuck
AnswerIf you've got no external leaks, check the coolant. Make sure you don't have any oil getting in the radiator. Then check the PCV system. If your pcv system isn't working properly, the crankcase can blow oil into the intake through the breather hose. Pull the plugs out and see if any are oil fouled. If you find only one that's fouled, you've located a cylinder with either a leaky valve stem seal or some sort of block or valve guide wear issue. If that's the case, you're looking at significant expense on the oil consumption. The fact that you don't see any smoke doesn't mean it's not an internal issue. Most modern engines run hot enough that there is little or any smoke unless they're burning a very large amount of oil.
The power loss could be from a different or the same cause. You should have it diagnosed to help you decide what you're going to do with this car. My initial thoughts are partially clogged catalytic converter or worn fuel pump, but the potential causes are many.
Oil usage is a minor concern as long as the car runs well. Even though you may have an internal engine problem causing the oil usage, it may run that way with no significant problems for quite a long time. It could be nothing more than rings stuck to the pistons.
A relative owns a Thunderbird which has used a quart in about the same interval since he's owned it. I believe he's put over 130,000 miles on it himself.
