Notice oil stains or burning smells under the hood? Don’t ignore these signs. Valve cover or gasket damage is a common culprit. What is a valve cover, failure symptoms, and repair tips?
What Is A Valve Cover?
Diesel engines have a valve cover, also referred to as a rocker cover, mounted atop the cylinder head. It encloses internal valve parts including rocker arms, pushrods, springs and stems, which manage engine air flow. This part has two core functions. It seals oil inside to lubricate valve components, and stops dirt, water and debris from entering the engine.
A valve cover gasket sits between the cover and the cylinder head to prevent oil leakage. Heavy equipment engines constantly endure intense heat, vibration and heavy loads. The gasket gradually wears down, dries out or cracks, making oil leaks a frequent diesel engine issue.
What Are the Signs of A Bad Valve Cover?
You’ll spot obvious signs when the valve cover or gasket goes bad.
- Oil leaks and dirty buildup: Dark wet oil gathers along the joint between valve cover and cylinder head. Dust mixes with leaked oil on work sites, forming thick grime on the engine. Oil dripping down from the engine top usually points to a faulty gasket.
- Burnt oil odor: A sharp burning oil smell means trouble. Leaking oil drips onto scorching parts like exhaust manifolds and turbos, burning right away. This stench also brings potential fire risks, endangering both machine and operator.
- Frequent low oil level: Engines need sufficient oil to stay lubricated and cooled. A worn gasket causes slow constant leaks, making oil level keep dropping. If you add oil far more often than usual, there is definitely an oil leak. Low oil can trigger overheating and serious internal engine damage quickly.
- Rough running and misfires: Oil leaks can hurt engine performance. Fuel injectors and wires sit under or run through the valve cover. Spilled oil contaminates wiring connections, leading to rough idle, misfires and power loss. Unstable running reduces work efficiency and poses safety risks.
How Do You Fix a Bad Valve Cover?
Fixing a leaking valve cover is pretty simple. Most leaks happen due to a worn gasket instead of the cover itself.
Start by finding the exact leak spot. Clean the engine thoroughly with degreaser, then start it briefly. Fresh oil stains will clearly show where the leak occurs. You just need to fit a new gasket once confirmed. Follow these basic repair steps:
- Clean surroundings: Wipe down the valve cover and cylinder head area first. Keep dirt out of the exposed engine interior.
- Take off blocking parts: Remove intake pipes, brackets and wiring that get in the way of the cover bolts.
- Detach the valve cover: Loosen bolts in a crisscross order to avoid bending the cover, then lift it off gently.
- Wipe sealing surfaces thoroughly: Take out the old gasket. Clear all leftover sealant and oil from both contact faces. Residue will lead to new leaks later.
- Fit new gasket and reinstall cover: Set the new gasket in place. Dab a little RTV sealant on corners if needed. Put the cover back and fasten bolts lightly by hand.
- Tighten bolts to standard torque: Use a torque wrench and stick to official torque specs and tightening order. Too tight cracks, parts or squeezes the gasket; loose bolts cause leaks again.
Replace the whole valve cover together with the gasket if you find cracks, warping or broken bolt holes.
How Much Does A Replacement Cost?
Repair costs mainly include parts fees and labor charges.
Parts prices vary a lot across North America based on replacement needs. A standard gasket set with gaskets and bolt seals is fairly cheap, costing $50 to $250 for most heavy machinery. Exact price differs by engine size, equipment brand and gasket design.
Cost jumps sharply if it is cracked or deformed and needs replaceing. Basic steel covers for old models start at about $200. Advanced aluminum or composite covers for new engines can hit $1500 and above, mostly due to built-in extra parts.
Conclusion
Replacing it is usually a simple job, and it’s not expensive. If you order a guaranteed-fit replacement valve cover from us, you can save a lot of money. Check our catalog to find the right part for your machine.
