Hey guys,

Facing a weird issue with my new 3XO diesel. There’s a slight thud sound from the rear left side when the car goes over potholes. It mainly happens when the rear tyre compresses and rebounds.

Service centre checked a few things:

Spare tyre – checked if it was loose, but it was sitting properly. Did a TD and the sound still came, so ruled it out.

Rear left suspension – checked and test driven again, same sound.

Then they suspected the sunroof (honestly I didn’t think it could be from the roof). During testing:

Sunroof open → same pothole, same compression → no sound  
Sunroof closed → same pothole → thud sound comes

I also checked with another major Mahindra SC in Hyderabad when I went there with a friend of mine who works as a Senior Engineer at M&M regarding a new 7XO issue from another customer. They did the same tests and suggested removing the roof rails and checking the bolts / roof alignment.

But another 3XO owner told me roof rails may actually be pasted rather than bolted. Is that true?

The technicians didn’t clearly explain the repair process. They mentioned body shop people might also be involved (not sure why), and the concerned person wasn’t there that day so I was asked to come later.

Now I’m a bit confused. The sound only comes on potholes, but it’s annoying since the car is brand new. At the same time, I’m not very comfortable with them opening up the roof area unless it’s really necessary.

Any 3XO owners here who faced something similar? Would really appreciate your inputs before I let the SC open up the roof area.  Slightly worried because the car is almost new and the sound feels like something you'd expect from a much older car...

Posting here hoping fellow Redditors notice this and share their experience or advice. Just hoping Mahindra stands by the product and helps resolve this properly if it’s a genuine issue.

Thud sound from rear left on potholes on brand new 3X0 – sunroof related?