Conditions when car trouble occurs
When shifting into the 3rd gear or in a high gear in particular, the transmission pops out. However the transmission shifts normal in other gears.
Possible cause of car trouble
1. The shift linkage is faulty.
2. The shaft movement is excessive
Troubleshooting car trouble
Because the transmission is very complex parts when it comes to vehicle, it is very difficult to explain in detail what is going on in the transmission why the transmission is popping out of the 3rd gear or the higher gear in particular when the shift linkage is at fault or when the shaft movement is excessive.
Just a simple explanation is that the shift linkage and the degree of input shaft play has something to do of having the transmission staying on the gear particularly on the 3rd gear or higher. With that said if one of these components has a problem like out of adjustments or has excessive movement then it can cause the transmission to jump out of a certain gear such as the 3rd or higher gear. All the causes mentioned above is just a possibilities of why the problem occurs and there might be other cause in which can only be determined when the transmission is inspected in actual condition.
What to do when the transmission pops out of 3rd gear or higher
If the car can be driven using different gear position then it is better because you can drive the car to the nearest car shop so that the mechanic can check the car, but if the car cannot be driven then have it towed to the nearest car shop.
Verify if the car is still under warranty because it will be covered and you will have problem on the cost if the car is not within the period of warranty, you are lucky if the car is within the specified warranty period set by the manufacturer because the dealer will take care of the problem and shoulder all the expenses that is incurred during the repair of the vehicle. Usually the mechanic will only have to adjust the shift linkage to fix the problem.
Having this kind of job on your car is pretty much expensive, if the car is not under warranty then you will shoulder all the expenses it will be a much expensive be need to bring the car to a reputable shop that specialize transmission repair, usually the mechanic will only need to adjust the shift linkage but if the problem is not fixed after the adjustments then the problem might be worst and the transmission is necessary to be inspected by a mechanic to determine the real cause of the problem.