I have a 2020 Nissan Frontier light truck that recently failed state inspection due to the emergency brake. Fortunately (or unfortunately) another shop 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 don’t know if there is a recall. All I know is I hauled some gravel through back roads once and it felt funny ever since - maybe the load was too heavy? Is it safe to drive? It may be a few more weeks before they schedule my repair.

A.

The issue based on you description is most likely the rear brakes are slightly 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 then can check the rotors for out of round and resurface or replace them as necessary. 

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.  They had it for four months. It has been at a friend’s house (good mechanic) for 10 months. He has gotten it running but then it shuts down. He feels that it is the brain.  The reason he feels that way is the brain is telling the security system the car is being stolen. He has done investigating on the situation and found that that year has had a lot of problems. The previous owner said that it had been doing that when they had it. Maybe you can help on this strange problem.

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, 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, 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. 

Q.

We recently purchased a 2021 Mazda Miata.  When we purchased the car, we also bought snow tires from the dealership.  Now that we have put on the snow tires the low air pressure light remains on (even though the air pressure is fine).  The dealer is telling us that there is a manufacturing defect in the sensor that the light will always be on and there is nothing they can do about it.

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 should 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 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 90,00 miles on it. I was in a situation that caused me to idle along for two hours in 90º 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, nearly cutting off at a stoplight during my exit. 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 communicated the status of the heat at the engine block to the computer. Any thoughts?

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 gases in the cooling system. The other common over-heat issue with this vehicle is the water pump impeller fails and doesn’t circulate sufficient coolant.