I bought a new 1/10th scale Slider on eBay and I've ran into a couple of problems. I bought a 2-cell LiPo for it from a local hobby shop and went to run it. Turns out the ESC was faulty, so replaced that, and it worked great, for about 24 hours. I ran it in the driveway to get used to it, then took inside into our basement and ran it on the carpet. Charging periodically to keep the LiPo from draining out completely. I went to run it earlier today, and it was slower than ever, on full charge. It kept getting worse, so I swapped out the transmitter batteries for a fresh set. Nothing happened. I figured I might have stripped out a gear, so I checked inside the case, nothing was wrong. I tightened up the slipper just a tad, and it didn't help at all. I even went so far as to check every single gear in the differential, and they were all fine. I've charged the battery to full capacity, and it is definitely not the problem. The motor does seem to be making a slightly different sound than normal, so could that be my problem? Please help me out, any advice is appreciated!

If it is a brushed motor, the problem could be a broken brush spring. I had this same issue on one of my cars before I went brushless. The spring that pushes the brush onto the comm probably broke and the brush is no longer making consistent contact to the commutator. Chances are, the broken piece of the spring may be stuck to the side of the motor can
In any case, you'll have to go to your hobby shop and buy new spring(s), they're cheap and relatively standard across all cars and motors.

+1 or go brushless

I haven't raced it yet, so I want to get used to competition before I go brushless, but I can't wait till I do. Out of curiosity, how much does a common sized brushless go for?

If you're looking at a more mainstream system, such as a Castle Creations Sidewinder (their lower-end but still crazy powerful ESC/motor combo), they got for around $130. Higher up is the Castle Creations Mamba Max, which is around $160-180 I believe. There are other brands that are also good, but I am most familiar with Castle. If you're looking to save some money and still get a great system, the eZRun systems are great bang for the buck. They are made in Hong Kong, but probably one of the highest quality pieces of equipment you can get from there. An eZRun system goes for anywhere from $45 to $100, obviously very dependent on the output power and features. Another thing to consider is sensored vs. sensorless, but that's a whole 'nother conversation. All the systems mentioned above are sensorless and they all work great.

The bottom line is that you'll spend around $100+ for a good brushless system, and since you already have a LiPo you should be in business quick

I just looked at my motor, and I honestly wondered "How am I supposed to get the can off?" Do I just try my best to bend the flaps away from electronics without ripping 'em off, or is there some special way I have to do this? I'm praying the first part, 'cause I don't feel like dragging out the power tools

Is your motor a closed endbell or open endbell? If it's closed then there's not much you can do. You're better off just buying a new motor, and one with an open endbell would be good
If it is an open endbell motor, then you shouldn't need to remove the can to replace the springs, get should be right on the back of the endbell...

Ok, I need to get a new motor, thank God it's only $20to get the exact same thing. I might bump up in power just a little bit, but I may need to run the stock engine for our local class. I'll ask when I go back to the hobby shop. Thanks for your help, man.

No problem . If you're going to bump up the power (buying a lower turn motor), you'll need to check what your ESC's minimum turn rating is. It's probably in the manual or maybe on the ESC itself.

this won't work if it's the RTR motor, they have a closed end bell.

Yup, I was thinking of the stock motor that came on my Evader, which was an open endbell design. Anyway, as the OP said, he will be buying a new motor because you can't really fix a closed endbell motor, unfortunately.

Upon further "review", I guess you could say, I think I might have just worn the motor out from running it at 160-170 degrees for over 5 minutes. Seems a little odd because it happened within the first 24 hours of getting it to run right, but I'm new, got a lot to learn.

Huh... That isn't that hot, but then again rtr motors are generally not that good in comparison to "real" motors
Good luck and have fun!

The stock esc and motors weren't very good in the Slider and not meant for use with a lipo battery at all. It sounds like the motor took a dump, time for a new one. Don't go too crazy if/when you go for brushless power or you will have problems with the transmission gears stripping. Upgrade what breaks and have fun with it.