With driving now limited, can I delay my next oil change?
John Paul, AAA Northeast's Car Doctor, answers a question from a reader who is unsure whether to put off an oil change.
Q. Now with limited driving due to coronavirus, when do I get the oil changed on my car? Based on the driving I am doing now, it only looks like I’ll be driving about 4,000 miles this year. Anything else I should do? A. Most vehicles use both time and mileage to determine service. Since you’re driving less, use the time measurement. As an example, in my car it is recommended that I change the oil at 7,000 miles or six months. I generally drive quite a bit, with recent changes. I will change the oil at about six months from the previous oil change. It is a good idea to also drive your car once a week or so to help keep the battery charged, wear any surface rust off the brake system, and exercise the car a bit. Q. I have a 2011 Chevy truck and the heater fan has suddenly quit working. I usually try to fix smaller repairs like this myself. I replaced the motor and checked and bypassed the resistor, and still the motor doesn’t turn. Any thoughts would be appreciated.A. The first step is to start with the basics and to check for current to the motor. In this case a voltmeter may mislead you and a test light could be a better tool. The meter may show 12 volts but may not have the current necessary to run the motor. Check the under-hood fuse box, where the fuse that protects the blower circuit is located. If the fuse is good, then check the power supply to the fuse. A broken or crimped wire at the firewall connection could certainly cause this problem. Q. I was with a group of high school kids at an event (I’m the car-pool dad) when a jacked-up diesel truck drove by and was spewing black smoke. The kids were commenting about it “rolling coal.” What on earth does that mean and what was up with this truck? A. Rolling coal is a slang term for modifying a diesel engine to billow large amounts of soot by burning extra fuel. The extra fuel allows the engine to produce more power. Doing this modification violates the Clean Air Act. In fact a couple of television hosts were recently ordered to pay $750,00 in fines for modifying and selling diesel trucks that violated the Clean Air Act. Q. I just purchased my first new car and I love it, but one thing has me concerned. After a long drive when I shut the car off, it crackles like a popcorn maker. What is wrong and should I be concerned? A. This is a normal occurrence. It is nothing more than the exhaust system and heat shields expanding and contracting as they cool. Especially the exhaust pipes, as the catalytic converter can reach temperatures of 1,500 degrees. As the heat shield around the converter cools it can make a snap, crackle, and popping noise. Q. I have a 2005 Hyundai Santa-Fe and the engine has started to knock. The vehicle has 190,000 miles on it and runs great, but has this slight knocking noise. I noticed it most recently after I changed the oil. I have always used the correct oil and a quality oil filter. What do you think is wrong and how long can I drive it this way?A. At this point you need to do a little more trouble shooting to determine where the noise is coming from. Using a piece of hose (a three-foot piece of garden hose would work) as a stethoscope will help determine if the noise is coming from the top or bottom of the engine. Listen at the valve covers and the oil pan. If the noise is in the oil pan, there is most likely a worn connecting rod or crankshaft bearing. I remember an older guy that I knew had a Ford F-150 with a bad rod bearing and he drove that truck (nice and easy) for years until the engine finally made so much noise it was too embarrassing to drive.
John Paul is AAA Northeast’s Car Doctor. He has over 40 years of experience in the automotive business and is an ASE-certified master technician. E-mail your car question to [email protected].
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