Has anyone experienced automatic transmission shifting problems with an I30? I have a 1998 that slips when shifting from 3rd to 4th. It only slips when excellerating slowly. Itfshifts fine if you are excellerate quickly

Does this transmissioin have any external solenoids?.

Does anyone have anyh guesses?

Thanks!!

You have one of three problems
1.low line pressure
2.internal hydraulic leak
3.worn clutch
Any slippage{rpm flare-up} of the transmission during an upshift is not a good thing.Aside from checking and adjusting the fluid level,there is nothing that can be done externally.The next step is to have a pressure test done at a shop.This will pin down the problem.
Good luck