1990 GMC Vandura 2500 Problems
RepairPal has identified the most common problems with the 1990 GMC Vandura 2500 based on complaints from actual vehicle owners. We'll tell you what the problem is and what it'll take to fix it.
An engine vacuum leak may develop from the throttle body gasket causing a higher than normal idle speed. Failed gaskets should be replaced.
The intake manifold gasket may develop and external engine oil or coolant leak. In some cases, an internal coolant leak may occur causing coolant to mix with the engine oil. Running the engine with a coolant/oil mix may result in engine damage. Replacing the intake manifold gasket should correct this issue.