Cars

Is it safe to drive my truck while waiting for a brake repair?

John Paul, AAA Northeast's Car Doctor, answers a question from a reader whose pickup has an emergency brake issue.

The 2020 Nissan Frontier. Nissan

Q. I have a 2020 Nissan Frontier that recently failed state inspection due to the emergency brake. Another shop later passed it. I brought it to the dealer, and they said it would take three days to fix, but due to parts shortages and technician illnesses it hasn’t been fixed yet. The only observation I can tell is it feels like a wave when it stops. I hauled some gravel through back roads once and it has felt funny ever since. Is it safe to drive while I wait for the repair?

A. Based on your description, the rear brakes are likely distorted due to driving with the heavy load. When the shop is repairing the parking brake, explain the wave/vibration feel when braking. The shop can check whether the rotors are out of round and can resurface or replace them as necessary. 

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Q. We were given a 2005 Chevrolet Colorado. It runs for a while then quits. We have had it in the shop with no luck. It has been at a friend’s house (a good mechanic) for 10 months. He’s gotten it running but it shuts down soon after. He feels that it is the brain telling the security system the car is being stolen. He’s been investigating and found that year’s Colorado had a lot of problems.

A. Certainly, the GM anti-theft system has been a problem on these vehicles as they age. Although typically the ignition switch doesn’t recognize the key and the vehicle will not start. In this case, I would start at the beginning. For any engine to run, it needs fuel, spark, and engine compression, and all three of these events need to happen at the correct time. When the engine dies, what is missing? If it is fuel, test the fuel pump circuit, if there is no spark, then look at this area. The idea that the ECM (computer) is faulty is possible, but my experience has been that many vehicles’ computers are replaced due to frustration rather than an actual failure of the part. 

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Q. We recently purchased a 2021 Mazda Miata.  We also bought snow tires from the dealership.  With the snow tires on, the low air pressure light has remained lit, even though the tire pressure is fine. The dealer says there is a manufacturing defect in the sensor causing the light to stay on.

A. The Miata uses direct style radio transmitters in each wheel that communicate the tire pressure to the vehicle’s computer. If the snow tires were installed on the factory wheels, there shouldn’t be an issue. If the snow tires were installed on an extra set of wheels, the sensors would need to be programmed. One possibility is that if you use a portable GPS or EZ Pass, and it is mounted near the center of the dash, it could be blocking the TPMS signal to the TPMS receiver antenna. 

Q. I have a 2003 Chevy Impala with 90,000 miles on it. I was in a situation that caused me to idle along for two hours in 90 degree heat, which I’m afraid hurt my car’s engine. When I shut the engine off for 15 minutes, it was difficult to restart, and I knew it was hot. Driving back home at highway speeds it was bucking and kicking. I took it to a local mechanic who changed out the thermostat, flushed the system, checked the head gasket, checked the fans, put on the diagnostics, and the usual things. After a month he still couldn’t figure out why it was still overheating and suggested I needed a new computer. I took it home and decided to do a search for little known causes of overheating. The only thing I came up with was a sensor that communicates the status of the heat at the engine block to the computer. Any thoughts?

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A. Idling for long periods of time is not a problem to a properly running vehicle. As an example, police vehicles idle for hours at the roadside. If the engine cooling fans are running as the engine gets hot, the coolant sensor and computer are functioning correctly. I would go back to the idea that a cylinder head-gasket has failed. You can check the head-gasket with a cylinder block-check kit (about $35) or find a repair shop with an exhaust gas analyzer. The gas analyzer and the block check kit do the same thing, they look for combustion gasses in the cooling system The other common overheat issue with this vehicle is that the water pump impeller fails and doesn’t circulate sufficient coolant. 

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] Listen to Car Doctor on the radio at 10 a.m. every Saturday on 104.9 FM or online at northshore1049.com.

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