My chunky boy is 1.5 kilos (that's 3.3 pounds) and I bet your boy is about the same. I weighed him in a shoebox on the kitchen scales I use for baking and when I said, "1.5 kilos George!" I'm sure he looked a bit embarrassed
Make sure you put the scales on the floor, not a table, as they try to jump out! My last girl died about 2 weeks ago and I was sooooo sad. I am trying to find a new friend for him but it might take a bit of time. George is neutered - we got him from a rescue and they neuter all the boys here so they won't have babies. I thought that it would be easy to introduce a new female and we found a lively young one who really liked him but unfortunately George is also a very nervous piggy and after about 10 minutes together he panicked and tried to fight her! This is pretty unusual for a male - generally they will try to woo any female! Poor Rosie was not injured but she had to go back to her old house (she was probably quite relieved) so now we have a challenge. I thought about another boy but it might mean more fighting... boars can be more difficult to pair up (although they have some good guides on this site about how to try it). I think what
we need is a pair of nice old ladies - they move slower and George wouldn't be so alarmed... if he panics and tries to fight them they can just live together in a cage next to him. Or maybe we would try to find a grumpy old boar in a rescue that nobody wants and have the two cages next to each other. The Covid virus has made things a bit more tricky here so it will take a bit of time and in the meantime he gets lots of attention in the day because he lives downstairs in the kitchen with me.
In some countries the females in rescues are spayed so they can't have babies and if you could find a spayed female it might be the easiest option for you. This is quite a big operation for a guinea-pig though so I don't think it's that common. Some are spayed for health reasons anyway, so it does happen.
I forgot to say last time about the two times we had experienced bar-chewing (I get distracted because I write a LOT you might have noticed!) One was when we had an older male who had been neutered and we had to wait quite a few weeks to introduce a female (it takes a while before they lose fertility). Well, we got that young female (Snowflake) and I thought to put them in with a barrier between so they could get to know each other before they went in together... I thought it was only polite! What do you know... Casper had very different ideas and after 12 hours solid of bar-chewing I gave up and let them in together while he still had some teeth left. There was a 5 minute whirl of running around and they were suddenly best friends... a proper Romeo and Julie-pig pair. The other time was when we looked after my friend's hamster (Fluffy) and that thing chewed it's bars ALL NIGHT LONG. Luckily we only had it for 3 days. I have never seen a pet who was so keen to get out of the cage - she actually had a little padlock on the door because she'd broken out before. My friend said they do it all the time (it's not their first hamster) but they don't hear it because they are all in bed with the door shut (Hamsters ARE nocturnal, and they are also solitary animals so she would have fought another one, not played). I thought then I would NEVER have a hamster... this pet just doesn't want to be a pet! Guinea-pigs are much better
I bet your boy is just thinking about getting out and having a look to see if any other pigs are around while it's quiet.
All the best!