Restoration Correct Original AC Delco Part Correct Fit And Finish Fits V6 And V8 Engines Made In USA Engine running rough? Is your check engine light on? It could be a failed Thermal Vaccum Valve on your 1978-1983 Malibu or Chevelle. This could be the cause of your problem, because this valve removes the vacuum applied to the distributor advance and disables the EGR valve while the engine is warming up, it's an intentional air leak in those circuits when the engine is cold. If it's broken off, or if one of the ears is broken off it becomes a vacuum leak which will disable both all the time, resulting in poor performance and a fault code. Don't trust just any replacement part on your 1978, 1979, 1980, 1981, 1982, 1983 Malibu or Chevelle.
| Make | Model | Years |
| Chevrolet | Malibu | 1978 - 1983 |
