GM 4.8L V8
4.8L oil leak repair
Rear main, oil pan and valve cover leaks on the 4.8L.
Why this matters on the GM 4.8L V8
Age and heat harden gaskets on these older engines.
Symptoms owners notice
- Oil spots
- Burning oil smell
What we check
- Leak trace with dye
Related causes we rule out
- Rear main seal leaks at the back of the engine
- Oil pan gasket leaks
- Valve cover gasket leaks
- The oil pressure sensor and its seal at the rear of the engine valley
- Oil cooler lines on trucks equipped with an engine oil cooler
Repair work involved
- Gasket and seal replacement
Repair considerations
- The engine is cleaned and, if needed, dye-tested so the true source is found — oil runs down and can look like a rear main leak when it starts higher up
- A rear main seal repair requires removing the transmission, so it is often timed with transmission work
- Oil dripping onto the exhaust can cause smoke and burning smells and should not be ignored