High-mileage car needs different oil

Dear Doctor: I have a 2007 Chevrolet Impala with 170,000 miles. It has some oil leaks. I’ve always used Mobil 1 Oil. Would changing over to a non-synthetic oil help? If I switch over and it doesn’t help, then can I revert back to synthetic oil?

– Jay

Dear Jay: No, I would not switch back to regular petroleum oil. At 170,000 miles of engine wear, the full-synthetic oil offers the best lubrication. I recommend using high-mileage synthetic oil.

Dear Doctor: I see many carmakers have 200- and 400-horsepower 2.0-liter engines – most are turbocharged and / or supercharged. Many of today’s engines with lesser horsepower output have materials, build tolerances and modern engine oil formulas to propel engine life expectancy to over 200,000 miles. Can the same be said with these high output 2.0-liter engines? What is your opinion on the expected life span of such high output engines?

– Tony

Dear Tony: All of my vehicles are either turbocharged or supercharged, with two of them having twin turbochargers. They have full synthetic oils, which offer great lubrication, and the engine fuel and timing management are also precise. The oil type and oil change intervals are very important. I have no problem recommending these high output 2.0-liter engines – as long as the car owner knows that regular service and premium gasoline are highly recommended.

Dear Doctor: My 2004 Honda Accord four-cylinder is hard to start after refueling. Eventually, after a few minutes of cranking, along with pumping the gas pedal, the engine starts up. I have tried leaving the car running when fueling, but it stalls anyway. Can you help?

– Jerry

Dear Jerry: The reason a vehicle is hard to start after a gas fill-up is the vent valve – or charcoal canister – has stopped allowing gas to be sucked into the engine by the vacuum when the engine is started. A failed EVAP part can also allow gas to flow up to the engine during the fill-up process, even without the engine running. Consult with an ASE-certified technician who has access to Identifix and Alldata to solve this problem.

Dear Doctor: I purchased the new 2016 Honda Pilot. After it rains or after washing the vehicle, water accumulates in the rear window seam. When I open the rear hatch water pours out of a hole surrounding the window. The water pours from the right side of the window. The dealer said this is normal. How can this be normal when I end up getting soaked sometimes? I noticed the roof liner trim has a gap – could this be the problem?

– John

Dear John: All vehicles have designs that will shed water. And it is true that some vehicles have only one drain. You should go back to the dealer and look at another Pilot. Honda’s redesigned Pilot (like all vehicles) is water-tested before leaving the factory. There should not be any water leaking to the inside of the vehicle.

Dear Doctor: In many articles the use of a “professional scan tool” is recommended. What are the brand names of the scan tools?

– Bill

Dear Bill: There are many professional scan tools available through tool dealers, such as Snap-On, Mac and Matco, who visit auto repair shops weekly. These scan tools can all communicate with the multiple computers and circuits that are in today’s vehicles. These professional scan tools cost $3,000 to $9,000 and require updates, either once or twice a year at an average cost of $1,000. If you are thinking of buying a used scan tool, then check to see if it can be updated and the cost to make it current.