Intermittent Braking or Sluggishness at Speed

Hi: I’m noticing some odd behavior from my Brand New (50 miles) Chevy Sonic. When I get to about 40-45 mph steady, the car seems to apply a small amount of braking every few seconds. The effect is strong enough that my head bobs forward somewhat. On a long drive, I could see it getting VERY annoying. It really "feels’ like braking and not like engine sluggishness, but I"m not 100% sure. Any ideas? I was thinking traction control.

Thanks for any help. I’m going to the shop next week but would be nice to be pre-loaded with some ideas, maybe even some things I could look into myself.

It really "feels’ like braking and not like engine sluggishness…

So it’s slowing significantly, presumably without brake lights coming on. Unsafe. Get to the dealer and take full advantage of your warranty.

@PatrickSquee

I’ll add a few things . . .

Make absolutely sure you give the service writer as many details as possible

Even better, if possible, go on a test drive with the mechanic who will be working on the car. Demonstrate the problem to him. And when it happens, tell him “I just felt it”

Just out of curiosity . . . does this car have a cruise control system that is supposed to maintain a set distance from the vehicles in front of you?

If it’s slowing enough to make your head bob without your letting up on the gas pedal, you need to get it back to the dealer ASAP. Your stability control system uses brake application to maintain the stability of the vehicle, and it could be misbehaving, causing application of the brakes inappropriately.

"does this car have a cruise control system that is supposed to maintain a set distance from the vehicles in front of you? "

Adaptive cruise control…on a $15,000 car?
Nope…

The OP definitely needs to get this car back to a Chevy dealership, as this is a potential safety defect. If they are not able to rectify the situation after 3 repair attempts, the OP should consider filing a Lemon Law claim with the manufacturer.

Be sure that each repair invoice states the problem that you have experienced, so that you have the documentation necessary in the event of having to go the Lemon Law route.

@VDCdriver

I asked because MANY of the standard features on new cars nowadays would have absolutely unheard of and/or reserved for luxury and/or sporty cars just a few years back

I know this for a fact, because many of the features that were on Benz cars when I was at the dealership, are now common . . . or standard . . . on all cars

I do not think my question was entirely out of the realm of plausibility

:grin: