Have only had my 2021 GMC Terrain SLT 2 months, almost to the day, and yet another unexplainable thing happens.
2 weeks ago I was in a Target parking lot. Came out of my parking spot and drove about 5 car lengths, having to stop for people coming out of Target. As soon as I do there’s a VERY loud CRACK sound from the front right passenger side. Felt it in the steering wheel and the car itself. Like if you’re sitting in the car and someone slaps it with their hand really hard. That kind of feeling. First thought was someone threw a big rock at the car, which didn’t make sense because I was in a parking lot, but that’s where my mind immediately went. Even though there were cars behind me and one to my right waiting to pull into my lane, I immediately got out of the car and went around to the passenger side to see what happened. When I got there, the guy in the truck to my right had his window open, and I asked if he heard that crack sound. He said he did. Didn’t see any damage, nothing on the ground underneath, so I went home and called the dealer to get it in. Couldn’t get me in for 2 weeks. That was today. Took it in this morning. But before I took it in…
Last night, the EXACT SAME THING happened, only THIS time it was MUCH worse. Again, I was driving on the road (about 30 mph) and had to stop for a red light. I come up to it and stop. Didn’t ever slam on the brakes. I was coasting up to the red light, so came to a gentle stop. As soon as I come to a COMPLETE STOP, a split second later the same CRACK sound happened, but this time it was 10x as loud. I mean alarmingly, scary loud. Same front passenger side. The whole car shook. My body moved. The feeling was as if there was a really heavy something in the back seat that slammed into the front seat as if I was going 30 mph and slammed on the brakes. Only my back seat is empty. Nothing in there at all. Or in the trunk. Nothing there either. I honestly thought something broke off the car underneath. Because I was in a very busy intersection I couldn’t get out of the car to check, but I was going to my son’s house which was about a mile away, so I just went there. Again, didn’t see anything on the outside, though it was dark out now. Was really afraid to drive it the 22 miles home, considering the immensity of the sound and feel, but I drove slower than normal and hoped nothing would happen before I got there.
So that next day, today, took it to the dealer. I knew he wouldn’t be able to duplicate either event and I told him so. Typical car event - that when something happens with your car, you take it to the mechanic and it doesn’t do the same thing and he can’t duplicate it. Anyway, he said they drove it twice and put it on the lift to look underneath and didn’t find anything and couldn’t duplicate it. Then he said he was “suspicious” and skeptical (like he didn’t believe me) because “it’s not like it happened a lot, it only happened 2 weeks apart, which doesn’t make any sense.” His words.
The car had 14.5k miles when I bought it 2 months ago. I put almost 400 miles on it in those 2 months. Other than the headlights issue in the beginning, car’s been fine. Now THIS happens. And this service guy doesn’t really believe my description of events, what it sounded and felt like. Like those things are impossible to happen.
Just if there’s any relation, this happened about a month and a half after having the underside rustproofed. Don’t know if that has any bearing or not. One of my thoughts about it is that maybe there’s a place under there where 2 spots meet, they rustproofed over that spot and it was that “joint” that broke apart and made the crack sound. Although I would think if something like that was even possible, it would happen while driving, not after having come to a complete stop. And not loud enough or forceful enough to shake the car and make my body move.
So here’s what I’m thinking and need suggestions for, because it’s the only thing I can think of - I want to buy the best recorder possible - don’t care what kind or price, because it has to be the best to do what I need it to do, and that’s to hopefully record this sound if it ever happens again. Need type to buy. Since I don’t have anyone who can drive with me every single time I drive my car to be a witness, the only thing I can think of is to record it. Turn the recorder on every time I drive the car and hopefully it will get at least the sound of the crack. Unfortunately only an actual person sitting in the car would be able to witness and feel the movement that goes along with it.
If anyone has ANY idea what could cause this event to happen - twice, one much worse than the other - please let me know. I’m extremely concerned about it, but I have to drive it unless somehow it can be identified and fixed. Of course, no one’s ever heard of this happening, and it’s not just an anomaly, it’s an impossibility.
