Why is my car is burning through oil?

John Paul, aka “the Car Doctor,’’ answers readers’ car-related questions.

By John Paul @johnfpaul

January 26, 2016

4 minutes to read

Q. I have a 2006 Mitsubishi Outlander with 190,252 miles on it. Within the past two years I have replaced the catalytic converters and since then, the car has been burning oil. Recently I had an oil change, then drove 275 miles and the check engine light came on. I checked it and found the engine had no oil. What could be the problem? By the way, what do you think of the latest Mitsubishi Outlander?

A. The catalytic converter failure is most likely a result of your Mitsubishi burning oil. The first and simplest check would be to ensure the positive crankcase ventilation (PCV) system is operating properly. If the PCV system is not working properly, this can result in increased oil use. Oil consumption can also be a result of higher than normal engine temperatures, worn piston rings and damaged valve seals. At this point, I would have a repair shop perform a complete diagnostic check of the engine. This should also include cylinder leak down and compression tests. Regarding the latest Outlander (2015 model), it’s a pretty good vehicle, packed with some great features and an outstanding warranty, but as a complete package I just feel a couple of years behind the competition.

Q. I am a 69 year old woman who has re-entered the workforce (real-estate sales) and I am trying to locate a used sedan, large or midsized, with AWD and regular turn-key ignition. I would also prefer to have comfortable adjustable driver seating with lumbar support and a tilt/telescoping steering wheel without overly complicated electronics.

A. I would start with a later model Ford Taurus or Toyota Avalon. These cars are dependable, have a great all-wheel-drive system and should satisfy all of your requirements. As with any used car purchase, you should have the carefully inspected by a reputable repair shop.

Q. My 2004 Hyundai XG350L with 78,000 miles has the air bag light on. I took it to the Hyundai garage and was quoted a price of $1600 plus labor to have the car fixed. I love the car and would like to keep it but can’t decide if I should fix it. I would appreciate your thoughts.

A. The Hyundai XG350 is a great car but does suffer from some rust issues. Before spending what could easily amount to $2000 on your car, I would want a technician to fully inspect the car to look for rust (some repairs were under a recall). If the car looks good, I don’t see any reason not to perform the repair.

Q. I have an older Chevy truck with a 350 engine and spark plugs six and eight get oil fouled. What problems am I looking for?

A. It is not uncommon on this engine to see valve guide wear. As the valve guides wear, oil is sucked by the valve seals and ends up in the combustion chamber. I would perform a compression test on the engine; if the compression is low in those two cylinders, you may be faced with an engine overhaul. In the short term, you could put in a slightly hotter spark plug or even a sparkplug anti-fouler. The anti-fouler won’t solve the oil consumption problem, but will keep the plug clean and the engine from skipping.

Q. I have a 2016 F-150 and I have a problem keeping my interior windshield clean. Neither I nor my passengers smoke in my truck, but within a few days after washing my windshield, there is a film back on it similar to a smoke film. I’ve tried various cleaning solutions but none keep it clean any longer than a few days. This is the only vehicle I’ve owned that this happens with. Any suggestions would be appreciated.

A. This film on the inside of the windshield is from the outgassing of all the plastics and foam in your truck. I have found that there isn’t much you can do other than clean the windshield periodically. My favorite glass cleaners (approved by my wife) are ZEP Glass cleaner, Invisible Glass, RainX and Sprayway, with Sprayway getting the slight edge. Once the window is clean, follow up with a microfiber cloth. This should get the windows nice and clean. If the car is parked in a garage, leaving the windows open just a bit will allow quicker outgassing.

Q. I have a 2014 Subaru Crosstrek, the transmission is very slow to engage, especially from reverse to drive; it takes three to four seconds before the car moves. I am afraid that when I back out into traffic, I’ll get rear ended because I can’t get out of the way fast enough. The other day on the highway, the car in front of me slammed on their brakes, and when I went to move into the left lane, the car behind me almost hit me because my car just didn’t move. The salesman said the car needed to be re-programmed, but then the service manager told me that there was nothing wrong with the car and did nothing. I believe this car is dangerous, what do I do? I called Subaru and opened up a claim. Clearly they know about this. I have two friends with 2013 Subaru’s and their cars don’t have this problem. Help!

A. I have driven several 2014 Subaru models and haven’t experienced this problem but have heard from readers with similar concerns. One reader reports that it can take up to seven seconds for the transmission to shift from reverse to drive. Since not every 2014 Subaru has this problem, it seems to me that it can be fixed. I would continue to work with Subaru-Customer Service, not the dealership, to try to get the matter resolved.