How To
John Paul, AAA Northeast’s Car Doctor, hears from a reader experiencing engine shaking in a 2016 Audi.
The Car Doctor hears from a reader experiencing engine shaking in a 2016 Audi. Audi
May 10, 2026 | 5:13 PM
4 minutes to read
Q. I would like your advice about a problem with my 2016 Audi Q5. The car started shaking while I was driving on the highway at around 75 to 80 mph. The check engine light came on, and the EPC light also came on. After that, the engine continued to shake at idle, and it sometimes took longer than normal to start. Later, when I had to move the car a short distance uphill into my driveway, the check engine light started flashing for a few seconds, then became solid again when I put the car in reverse. At this point, the car is parked at home, and I am not driving it. Could you please advise me on whether this sounds like an engine misfire, whether it is unsafe to drive, and whether I should have it towed directly to a mechanic?
A. A flashing check engine light is a strong indicator that the engine is misfiring. The EPC (Electronic Power Control) light signals a fault in the throttle system or related electronics and often appears along with a misfire condition. The misfire could be the shake you are feeling at an idle. I would recommend having the car towed rather than driving it, as continued operation could cause further damage.
Q. I own a 2021 Chevy Colorado with an automatic transmission and a four-cylinder engine. The truck has only 37,000 miles. In December 2024, the truck overheated and had to be towed to a dealer. A freeze plug had to be replaced, which was expensive mostly due to high labor costs. While I feel the truck may not be the most robustly built, its size is perfect for my needs. Recently, I have noticed a shudder in the transmission during acceleration and downshifts. My initial research suggests this model has had torque converter issues and that a transmission fluid service may help. Do you think I should try that first? I am inclined to repair it given today’s high used truck prices, but I am concerned about what might fail next.
A. A transmission fluid service may help reduce shudder, but I would also want the transmission pan inspected. Any debris in the pan can indicate internal wear. These transmissions have had issues with torque converters and valve bodies. While I am generally not a fan of additives, considering the potential cost of a major repair, trying a product like Lubegard Instant Shudder Fixx may be worthwhile as a possible solution.
Q. My 2016 Honda CR-V is overdue for new spark plugs at 109,000 miles. Should I spend the money on NGK plugs, or save with a less expensive aftermarket brand I found online? Also, do I need a thin-wall socket for this job?
A. While NGK spark plugs can be expensive, they are the brand I would recommend since they are original equipment. Since they are typically replaced every 100,000 miles, it is worth using a high-quality part. Yes, you will need a thin-wall 14mm spark plug socket. I would also inspect the spark plug tube seals and replace them if there are any signs of wear.
Q. When I plug my iPhone 17 into my Toyota Camry, Apple CarPlay sometimes connects and sometimes does not, although the phone always charges. My sister has experienced the same issue with her Honda. Why isn’t CarPlay consistently connecting?
A. We are seeing more issues with technology compatibility. It often seems that after a phone operating system update, features that once worked may become inconsistent. Make sure both your vehicle’s software (if it supports over-the-air updates) and your phone are fully up to date. Trying a different cable. Cheap Lightning or USB-C cables are a very common issue. Also look at the phone port (I need to clean lint out of mine from time to time) and of course check permissions/settings, especially after operating system updates.
Q. While shopping for a new hybrid vehicle, I’ve noticed that many models no longer come with a spare tire. I’ve looked at the Toyota RAV4, Honda CR-V, and Subaru Forester, and none includes even a compact spare – just a sealant kit and inflator. That might work for a simple puncture, but not for a sidewall blowout. Also, can tire sealant damage the tire pressure monitoring system? I’ve seen aftermarket spare tire kits, but they take up cargo space. What are your thoughts?
A. This has become a common issue, even for AAA roadside assistance providers, as what used to be a simple tire change can now require a tow. As you mentioned, mobility kits work for minor tread punctures but not for more serious damage like sidewall failures. Some older sealants can affect tire pressure monitoring sensors, although many modern formulas are designed to minimize this risk. In some vehicles, it is possible to fit a compact spare in place of the factory kit by removing the foam insert. Aftermarket spare kits are also an option, though they do reduce cargo space.
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 Doctor question to [email protected]. Listen to the Car Doctor Podcast on Apple Podcasts or other popular podcast sites.
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