Dear Doctor: I have a 2003 Hyundai Elantra with 135,000 miles. Occasionally when I fuel up the pumping continually stops, as if the tank were already filled. I then have to gingerly continue fueling until the tank is full. It's pretty frustrating. Also, sometimes when the tank is full the car runs with a rough idle and sometimes stalls. This disappears when I run the car a few miles. Is this something I can diagnose and repair easily? -- Victor
Dear Victor: Today's vehicles have a system to keep the gas fumes in a charcoal canister vs. emitting into the air, called the evaporative emission system. Connected to the gas tank by plastic hoses, electronic and vent solenoids, the fumes get trapped in the canister while driving and especially when filling the tank. There is another valve that opens as needed called a purge valve. This valve opens and sucks the fumes out of the canister and then burns the fuel in the engine. If the vent valve fails, then the pressure builds up and shuts the pump nozzle off. As for car the running rough after the fill up, the gas vapors travel up to the engine and cause a rich condition until the gas is sucked out of the canister. Have a technician check all the systems.
Dear Doctor: I have a 2000 GMC Jimmy with the V-6. I have tried to change the spark plugs, but I was unable to remove the spark plug on the driver's side behind the steering column. How do I do this? -- Chris
Dear Chris: Welcome to my world. On some vehicles the intake manifold has to be removed, but this is a simple removal on the Jimmy compared to other makes. You need a 5/8 flex spark plug socket or a regular spark plug socket with the 5/8 hex nut size on the end and use a 5/8 wrench on the socket. Another way is to move the intermittent steering shaft out of the way. Do not give up. You can do it.
Dear Doctor: I have a 2009 Chevy Suburban with a 5.3-liter engine. There's an oil consumption problem and I am going to the dealer every 1,000 miles to have the oil topped off. The dealer says this is acceptable. The Suburban only has 35,000 miles on it. Can you tell me the amount of oil loss there should be every 3,000 miles? -- Kenny
Dear Kenny: Oil consumption is common in a lot of today's engines. The 1,000-mile per quart of oil usage is in line with a lot of manufacturers. What can you do? Ask the dealer to check the PCV system and breather system to ensure they're working as designed. The dealer will not suggest a change in oil type or viscosity, but I would suggest a change in the oil viscosity to 10W40 or even 15W40. There is also a high-mileage full synthetic available.
Dear Doctor: I own a 2012 Lexus CT200 Hybrid. The original outside temperature gauge never reads correctly, but I was told there was nothing wrong with it according to the electrical diagnostics. Also, the gas gauge doesn't register properly. The car holds 11.9 gallons, so when the needle is on half full it should take about 6 gallons, but it takes somewhere roughly between 3.8 to 4.2 gallons. The service department keeps telling me their diagnostics say the gauge is perfectly fine. Do I have a bad gauge? -- Mel
Dear Mel: The outside temperature reading uses a small sensor and it is located in the front grille area. We replace faulty temperature sensors often and they are inexpensive. As for your gas gauge, it is a small float device. It's only a gauge and will never be 100 percent accurate. This holds true for all vehicles.
Dear Doctor: We're considering the purchase of a new Subaru Outback. My daughter has a 2005 Subaru Legacy, which required a major service at 30,000 miles. I learned the new Outback also requires a major service at 30,000 miles with an estimated cost of $600. Another major service is suggested at 60,000 miles. Our 2004 Toyota 4Runner didn't require such a service until 60,000 miles. Do you know why the difference? -- Jane
Dear Jane: All vehicles need service at specific mileage intervals. You need to find out exactly what is entailed in the services. You can also ask your local service center what the services would cost from them. The ownerís maintenance book should also have a list of recommended services and replacement of worn parts. -- Junior Damato, Motor Matters
Junior Damato is an ASE-certified Master Technician. Email questions to firstname.lastname@example.org