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Beware of Sludge Buildup with Longer Oil Change Intervals

By Junior Damato, December 23rd, 2017

strong>Dear Doctor: I own a 2011 Hyundai Azera with the 3.8-liter V-6. Why would a #3 connecting rod bearing destruct, shedding bearing debris, inside a V-6 engine that's lubed with quality synthetic oil? I acquired the Azera when it had 30,000 miles from a Hyundai dealer and immediately changed to Mobil 1 extended service oil and used a NAPA oil filter. At 37,000 miles I again changed the oil and filter using a NAPA and Pennzoil synthetic. Now at 42,200 miles the engine developed a knock upon starting that sounded like a collapsed hydraulic lifter and the noise stopped after about 5 seconds. I took it to the dealership where I learned the problem is a rod bearing failure. My vehicle's engine interior is free of sludge and crud and the car has not been hot-rodded. Bob

Manufacturer photo: 2011 Hyundai Azera
Manufacturer photo: 2011 Hyundai Azera

strong>Dear Bob: There are many reasons for internal engine failure that develop without initial signs. Sludge still builds up, even with today's excellent engine oils when the oil is run low and hot, and then lacks proper lubrication properties. One of my biggest concerns is the automaker's longer engine oil intervals that they recommended today; I see 80 percent of the vehicles low on engine oil that we service at my shop. And these conditions show up at about the 40,000-mile/5-year mark.

strong>Dear Doctor: My Chevy Corvette is equipped with run-flat tires. The car has always had a hard ride and the tires are noisy. Would non-run-flat tires improve the ride? I am aware of the disadvantage of not having a spare tire in case of a flat. Melvin

strong>Dear Melvin: I personally have swapped out many vehicles with non-run-flat tires, including my own Corvette. I can tell you the ride will be much softer, smoother, and quieter. I do recommend the change over to non-run flats. When you select the tire choose a non-aggressive tread pattern tire. You do not need a performance-rated tire, unless you take the car to a track on a regular basis.

strong>Dear Doctor: My 2009 BMW has always used a lot of oil, but I've been told by my service center that "the engine was designed this way." Oil use is now to the point of adding 1 quart every 250 miles. A sour smell is evident, as is smoke from the exhaust. BMW quoted approximately $12,000 to fix, while a local mechanic quoted about $9,000. I believe the material BMW used for the 32-valve seals is inferior. My disappointment with this BMW is immeasurable; it's not worth spending $9-grand on a 2009 car. Do you have thoughts on this matter? Geri

strong>Dear Geri: BMW vehicles are known to be very expensive to repair and the majority of their engines burn oil. I see this every day on a variety of BMW vehicles. There is no easy fix and, as you found out, it's expensive. In my opinion, I think it's very unfortunate that BMW has not made monetary allowances for engine problems such as yours.

strong>Dear Doctor: I have a 2011 Chevy Traverse AWD with less than 23,000 miles. I plan on changing the transmission, rear differential, and transfer case fluids using OEM fluids. Is that small hex bolt really the transmission drain? Where is the transfer case located? Also, does my 2002 Honda CRV AWD have a transfer case? John

strong>Dear John: Before trying to do any service on this vehicle or any other vehicle, purchase a one-year subscription to Alldata. You can download and print all of the instructions for the drain and fill locations, the fluid amounts, and how to actually drain and refill the fluid. On your Honda, the transfer case is located on the front trans-axle assembly. Use only factory-approved fluids.

strong>Dear Doctor: Have you noticed any issues with the 2005-2007 Jeep Commander models? I see that Jeep no longer makes them. How will this affect someone who may want to purchase a used one? Candi

h2>Dear Candi: Automakers change vehicle models over time

Big Drop in Fuel Mileage: Get Engine Test


Big Drop in Fuel Mileage: Get Engine Test

strong>Dear Doctor: I have a 2014 Ford F-150 with the EcoBoost engine. The dealership cannot tell me why my gas mileage is at 9 mpg. It was 24 mpg when I purchased it. Can you help me out? Gerald

Gas Mileage Misread: Fuel System Needs Attention


Gas Mileage Misread: Fuel System Needs Attention

strong>Dear Doctor: I own a 2006 Ram 2500. The mileage calculator says I'm getting 30 miles per gallon in fuel economy, but I'm actually getting about 20 mpg. What should I do? Mark

Car Shakes at Idle: Check for Multiple Fault Codes


Car Shakes at Idle: Check for Multiple Fault Codes

strong>Dear Doctor: My 2009 Toyota Camry with 199,600 miles has a check engine light showing the codes P0101 and P0170. I have already replaced the MAF sensor, PCV valve, throttle body, the car's computer, O2 sensors, cam sensor, crank sensor, fuel pump, injectors, and fuel pressure regulator. I also checked for multiple vacuum or air leaks, and the cabin air filter, spark plugs, alternator, and battery have all been checked over the course of a year. Now the car has both codes showing consistently and it shakes at idle. What should we do? Cheyenne

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