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Oil pan gasket leak symptoms

Oil pan gasket leak symptoms and causes

An oil pan gasket leak is pretty easy to diagnose once you get the vehicle up in the air. But you can get some idea by paying attention to these symptoms of an oil pan gasket leak.

leaking oil pan gasket

Oil pan gasket leak symptoms

Symptom #1: You see dark puddles of oil under your car after sitting overnight

Oil that leaks out of the oil pan gasket will slowly drip down the side of the oil pan after you shut off the engine. In the morning, you’ll see a puddle of dark oil under your vehicle. The leak could be coming from a valve cover gasket, timing chain cover gasket or the oil pan gasket. Either way, a puddle of oil under your car means you’ve got a leak that should be checked out.

Oil puddle under car
Symptom #2: Your oil light comes on while driving

Some luxury vehicles have an oil level sensor that detects a low oil level. But most vehicles just have a low oil pressure light. If your oil light comes on while driving, pull over immediately and shut off the engine. Then check the oil dipstick. If your engine is low on oil, you’re either leaking oil or burning it. Either way, you must get it checked out.

Symptom #3: You smell a burning smell coming from the engine compartment

Oil leaks can drip onto the hot exhaust pipes, causing a strong burning smell. Get that checked out right away.

What causes an oil pan gasket leak?

Gasket leak cause #1 — plugged PCV valve resulting in a blown oil pan gasket

All engines produce blow by; combustion gasses that seep past the piston rings an into the crankcase. The positive crankcase ventilation system (PCV) is designed to suck the blowby out of the crankcase and burn it in the engine. The PCV valve is a one-way valve designed to allow airflow from the crankcase to the intake manifold but prevent an engine backfire from igniting the blowby gasses in the crankcase. If the PCV valve gets plugged up, it prevents airflow, causing pressure buildup in the crankcase. That pressure buildup can cause the oil pan gasket to blow out, causing an oil pan leak. For more information on how the PCV system works, see this post.

Always check the condition of the PCV valve any time you have a gasket leak.

Gasket leak cause #2 — overfilling oil

The oil pan gasket is not designed to seal off the pressure of an overfilled oil pan. It is only designed to prevent oil splash from leaking out of the sealed area.

Gasket leak cause #3 — gasket shrink or deterioration

Neoprene and composite gaskets degrade over time and high temperature. The rubber takes a “set” and the initial bolt torque no longer holds the gasket tight enough to the sealing flanges. You can try tightening the pan bolts slightly, but if that doesn’t work you’ll have to replace the neoprene oil pan gasket.

Gasket leak cause #4 — improper oil pan gasket installation

Most modern silicone gaskets are designed to be install DRY without any added adhesives or room temperature vulcanizing (RTV) sealants. Add an RTV sealant can actually cause the gasket to leak.

For information on oil pan gasket replacement costs, see this post

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