Elantra won't shift gears

My Elantra has a manual transmission. For some reason, I’m unable to shift gears while the engine is running (this has gotten worse over last few weeks). However, I can shift into any gear while the car is off and then start and run it. To shift gears, engine must be turned off, gear shifted, and then engine restarted. (Don’t worry, I’m not still driving it on the road!) The clutch was recently replaced, although I’m not sure whether this has anything to do with the problem.

One website I saw suggested it might be the slave cylinder and to check this by putting the car on an inclined surface in first gear and then pressing the clutch to see if car rolls backward. When I did this, car did roll, suggesting (at least according to this website) that the problem might be something else.

Thanks for your help and expertise!

You have clutch issues. The slave or master cylinder for the clutch is probably leaking or has air in the system. Have you checked the clutch hydraulic fluid level? It may just be low.

Did you check the clutch fluid level? It may be low, which would cause this problem.

The clutch is not disengaging fully when you step on the pedal. The problem is probably in the hydraulic system, as you suggested. It may be leaking fluid, either externally or internally, and not allowing the clutch to fully disengage.

Time to visit your mechanic.

After the clutch was changed and the problems started developing we took it back into the shop and they made sure there wasn’t any air in the system. This seemed to work briefly but then the problem redeveloped.