A seal in the 4 cylinder engine around the balance shaft tends to fall out, causing a large oil leak. There is a retaining device available to prevent the seal from falling out, which can be put in place during routine timing belt maintenance.
Resources for the Repair and Maintenance of your 1999 Isuzu Oasis
1999 Isuzu Oasis
1999 Isuzu Oasis Problems
The AC evaporator can collect mold and give a foul smell. The evaporator will have to be disinfected or replaced to repair this issue.
The AC evaporator drain can clog and cause a water leak inside the vehicle, usually on the passenger floor. Cleaning the drain will fix this problem.
There is an issue where the transmission can have a torque converter problem, or the computer monitoring the torque converter can misinterpret the information, and in either case this can cause the Check Engine Light (MIL) to illuminate. The problem will need to be diagnosed and depending upon what is causing the issue, the transmission will have to be repaired or the computer replaced.
The front brake rotors can warp and cause a vibration when braking. The rotors will need to be machined or in cases where they are worn to thin, replaced to correct this issue.