Heater core leaks are common in this model, more so if the wrong anti-freeze/coolant is used in the cooling system.
1990 Volkswagen Jetta Problem Reports
RepairPal Verified 1990 Volkswagen Jetta Problem Reports
Electrical issues that are difficult to diagnose—and sometimes intermittent—are typically due to ground wiring issues. The most troublesome ground locations are under the battery or at the engine.
Ignition wire breakdown is common, resulting in misfires.
Reverse gear failures and noise in the manual transmission models are common.
To ensure longevity of the engine, our technicians recommend to follow the maintenance schedule for the timing belt.
Shifting issues due to internal problems in high mileage automatic transmissions can be difficult to resolve without transmission replacement.
Head gasket failure is common on higher mileage vehicles.