Collection: Cylinder Heads

Cylinder Heads and Valve Covers

Easy Life Auto Parts stocks cylinder heads, valve covers, and the gaskets and hardware that go with them for a wide range of gas and diesel engines, and we ship worldwide. If your engine is running rough, losing coolant without a visible leak, or has oil seeping from the top of the engine, you're probably looking at a cylinder head or valve cover issue.

What the Cylinder Head Does, and Where the Valve Cover Fits In

The cylinder head sits on top of the engine block and houses the valves, valve springs, and in most modern engines the camshaft(s) that control when those valves open and close. It's where the combustion chamber is formed, and it has to seal perfectly against the block through the head gasket while managing extreme heat and pressure on every single combustion cycle. The valve cover sits on top of the cylinder head and seals in the valvetrain, keeping oil contained while letting the camshaft and valves do their job. Despite the name similarity, a valve cover leak and a cylinder head problem are very different repairs — one is usually a simple gasket job, the other can mean pulling the head off the engine entirely.

Signs of Cylinder Head or Valve Cover Trouble

• Oil leaking from the top edge of the engine, often dripping onto the exhaust manifold and burning off with a smell — classic valve cover gasket symptom
• White, sweet-smelling smoke from the exhaust, often pointing to coolant getting into the combustion chamber through a failed head gasket
• Coolant disappearing with no visible puddle under the car, or coolant mixing into the oil (a milky appearance on the dipstick or filler cap)
• Overheating that happens quickly and repeatedly, especially combined with bubbling in the coolant reservoir
• Rough idle, misfires, or a check engine light tied to specific cylinders, which can point to a cracked head or valve seat issues
• Visible cracking or warping on the head's mating surface if it's been removed

A failed head gasket is one of the more serious failures on this list — driving on one for an extended period risks warping the head itself from overheating, turning a gasket job into a much bigger repair.

Choosing the Right Cylinder Head or Valve Cover

Cylinder heads are specific to engine family, and often to specific years within that family if the engine went through a mid-cycle revision — port design, valve size, and combustion chamber shape can all change even on an engine that kept the same name. Match your OE casting number, found stamped on the head itself, or your full engine code before ordering. Valve covers are generally more forgiving but still vary by engine variant, especially where sensors, breather ports, or variable valve timing solenoids are mounted directly to the cover. If you're not sure which version you have, send us your casting number or VIN through contact us or request a part and we'll help confirm fit.

Buying Guide: New vs. Remanufactured vs. Used Cylinder Heads

Option	Best for	Trade-offs
New (bare or assembled)	Highest confidence in a clean repair	Highest cost, especially fully assembled with valves installed
Remanufactured	Good balance of cost and reliability	Resurfaced and pressure-tested, but check whether valves/springs were replaced or just reused
Used	Budget repairs on lower-value vehicles	Unknown internal wear; always have it pressure-tested before install

For most repairs, a remanufactured head that's been resurfaced, pressure-tested, and fitted with new valve seals is the sweet spot between cost and reliability — you're getting known quality without paying full new-part price.

Installation and Maintenance Tips

Head gasket installation is torque-sequence sensitive — skipping the manufacturer's bolt tightening pattern and sequence is one of the most common causes of a brand-new gasket failing early. Always replace head bolts if they're the torque-to-yield type, since reusing stretched bolts won't clamp properly even with a new gasket. On valve cover jobs, don't overtighten the cover bolts — valve covers are often made of lightweight material or plastic on newer engines and will warp or crack under excessive torque, causing the exact leak you were trying to fix. Clean both mating surfaces thoroughly and use the gasket type specified for your engine, since some newer engines call for a specific sealant rather than a traditional gasket alone.

Frequently Asked Questions

How do I know if it's a valve cover leak or a head gasket leak?
A valve cover leak drips oil from the top edge of the engine with no coolant involvement. A head gasket leak usually involves coolant loss, white exhaust smoke, or oil and coolant mixing — much more serious symptoms.

Can I resurface my own cylinder head instead of replacing it?
Resurfacing (machining the mating surface flat again) is a common and valid repair if the head itself isn't cracked or excessively warped, but it requires precision machine work, not a DIY job.

Do aluminum and cast iron heads fail differently?
Aluminum heads are more prone to warping from overheating due to how the metal expands, while cast iron heads are heavier but more tolerant of heat cycling. Both can crack under severe enough overheating.

Is it normal for a valve cover gasket to need replacing more than once?
If you're replacing the same valve cover gasket repeatedly, check for an overtightened or warped cover, or a PCV system issue causing excess crankcase pressure that pushes past the seal.

Do remanufactured heads come with a warranty?
Most of the remanufactured heads we carry include a warranty period — check the listing and our warranty page for specifics.

Why Buy From Easy Life Auto Parts

We stock cylinder heads, valve covers, and related gaskets for a wide range of gas and diesel engines, and we ship worldwide. Every listing includes casting number and engine code detail so you can confirm fitment, and our team is glad to help if you're unsure. See our related engine parts, gaskets and seals, and used engines collections for the rest of what a top-end repair usually needs.

OHV, SOHC, and DOHC: Why Head Design Varies So Much

Not all cylinder heads are built the same way, and the design affects both how the engine performs and what parts fit it. Overhead valve (OHV) engines keep the camshaft down in the block and use pushrods to operate the valves, which keeps the head relatively simple and compact — common on many domestic V8s. Single overhead cam (SOHC) engines move the camshaft up into the head itself, directly operating the valves (sometimes through rocker arms), simplifying the valvetrain compared to pushrods. Double overhead cam (DOHC) engines use two camshafts per head, one for intake valves and one for exhaust, allowing more precise valve timing and typically more valves per cylinder. If you're sourcing parts, knowing which design your engine uses matters immediately — a DOHC head is a far more complex (and expensive) piece than an OHV head, and the two aren't remotely interchangeable even within the same engine family's displacement range. You can read more about how these designs work on Wikipedia's cylinder head article.

Head Gaskets: The Part That Fails Quietly Until It Doesn't

A head gasket seals the combustion chamber, coolant passages, and oil passages between the block and the head all at once, which is why its failure modes vary so much. A gasket that fails between a combustion chamber and a coolant passage causes the classic white smoke and coolant loss. One that fails between a combustion chamber and an adjacent cylinder causes a loss of compression and power without necessarily any visible fluid symptoms. One that fails between an oil passage and a coolant passage causes the dreaded milky oil, which usually means the engine needs to come apart regardless of how minor the leak seems. Overheating is the most common root cause of head gasket failure, so if you've had a cooling system issue recently, keep an eye on these symptoms even if the gasket seems fine at first.

Valve Seals, Valve Springs, and Why a "Simple" Valve Cover Job Can Grow

When a valve cover comes off for a gasket replacement, it's common to notice other valvetrain wear at the same time — valve seals that have hardened and are letting oil past into the combustion chamber (showing up as blue smoke on startup), or valve springs that have weakened over time and affect valve timing at high RPM. Neither of these issues requires pulling the full head on most engines, but they do require more disassembly than a basic gasket swap. If you're already in there for a leak, it's worth at least inspecting these components, since labor to access them is the expensive part — the components themselves are relatively inexpensive by comparison.

Combustion Chamber Shape and Compression Ratio

The shape of the combustion chamber machined into the cylinder head directly affects compression ratio and how efficiently the engine burns fuel. This is why performance-oriented aftermarket heads sometimes advertise a different chamber volume than stock — a smaller chamber volume raises compression ratio, which can increase power but also increases the risk of knock on lower-octane fuel or in engines without the ignition timing adjusted to match. If you're considering an aftermarket performance head rather than a stock replacement, factor in whether your fuel and tuning can support the resulting change in compression.

Overheating, Climate, and Why Cooling System Health Comes First

Because overheating is the single biggest cause of head gasket failure and warped heads, cooling system health matters just as much as the head itself when you're trying to prevent a repeat failure. Hot climates push cooling systems harder during long highway drives or stop-and-go traffic, and any marginal weakness — a slightly low coolant level, an aging radiator, a thermostat that's starting to stick — shows up faster. Cold climates bring their own risk: coolant that's too diluted or the wrong type can freeze and cause damage, and a head that's already been through a heat cycle from a prior gasket issue can be more prone to cracking from thermal stress in a hard freeze. Before or alongside any head gasket or cylinder head replacement, it's worth having the radiator, thermostat, and cooling fan checked, since reinstalling a new head gasket on a cooling system that's still marginal is a good way to end up back here again within a year.

Warpage: When Resurfacing Isn't Enough

Resurfacing a cylinder head — machining the gasket mating surface flat again — fixes minor warpage from heat, but there's a limit to how much material can be removed before it affects valve geometry, combustion chamber volume, or the head's structural integrity. A machine shop checking a head for resurfacing will measure warpage against a spec, and a head that's warped beyond that spec, or one that shows cracking (especially between cylinders or around the combustion chamber), needs to be replaced rather than resurfaced. This is one of the more common reasons a "simple gasket job" turns into sourcing a full replacement head instead — the gasket wasn't the only thing that failed.

PCV Systems and Valve Cover Leaks That Won't Quit

A positive crankcase ventilation (PCV) system manages pressure inside the engine, and when it's not working correctly — a clogged PCV valve, a torn hose, or a failing valve itself — it can build up excess pressure in the valve cover area. That extra pressure pushes against gaskets and seals that would otherwise be fine, causing a leak that keeps coming back no matter how many times you replace the valve cover gasket. If you've replaced a valve cover gasket more than once on the same vehicle without a clear installation issue, checking the PCV system before buying another gasket can save you from repeating the same fix a third time.

Getting the Order Right

Cylinder heads are heavy and expensive enough that a wrong-fit return is a real hassle, so confirm your casting number and engine code before ordering. We ship worldwide, and our shipping page covers details. If something doesn't fit, see our returns and warranty pages, and track a shipment from track order.

Pre-Purchase Checklist for Cylinder Heads and Valve Covers

• Pull the casting number stamped on your current head, or match your full engine code — don't rely on the general engine family name alone
• Confirm whether you need a bare head, an assembled head (with valves and springs installed), or just a valve cover
• Check for cracking or excessive warpage before deciding between resurfacing and full replacement
• Have your cooling system inspected if the failure was overheating-related, to avoid a repeat failure
• Note whether sensors or VVT solenoids mount to your valve cover, since not every cover for an engine family carries the same provisions

These checks take a few minutes but prevent the two most common mistakes on this category — ordering a head that doesn't match the exact casting, and replacing a part without addressing why it failed in the first place.

Gaskets and Sealants Worth Getting Right

Beyond the head gasket itself, intake and exhaust manifold gaskets are often replaced in the same job since they're disturbed during removal and rarely survive reinstallation intact. Using the gasket or sealant type specified for your exact engine matters — some modern engines use a liquid sealant in combination with, or instead of, a traditional gasket in certain locations, and substituting a generic RTV sealant where the manufacturer specifies something different can lead to leaks or even sealant breaking off and clogging oil passages. Check our gaskets and seals collection for the supporting parts a head or valve cover job typically needs.

Buy With Confidence

Easy Life Auto Parts stocks cylinder heads, valve covers, and related hardware for a wide range of gas and diesel engines, and we ship worldwide. Every listing includes casting number and engine code detail, and our team is available through contact us to help confirm fitment. If the exact part you need isn't listed, use request a part and we'll work on sourcing it.