Jim Grant's Tech Tips
‘96 Chevy Suburban, Massive Oil Consumption
Q: I have a ‘96 Chevy Suburban with a 454 engine. It had an external intake manifold water leak. I was preparing for vacation so I let a shop replace the gasket. The car never burned oil before. I drove it one week before leaving on a RV trip. The first fuel stop it was two quarts low. It burned a quart every 200 miles for the remainder of the trip. I was towing a 6500 lb trailer.
- Thomas Mehrkam
A: If all you're saying is true I would suggest having the intake manifold gasket checked. The intake manifold gasket in your application can be mispositioned, allowing a vacuum leak into the crankcase of the engine at the lifter valley. Because the engine is so large in your vehicle the computer would likely mask over the running problem. Using a computer scan tool you would likely see short term and long term fuel trim readings that would indicate that the computer is compensating for the vacuum leak. A leak in this area would also explain the sudden oil consumption problem. Don’t let this problem go, get it checked out soon. It could cause other more costly problems if ignored.