How to Tell If Your Hood Struts Are Bad

You know your hood struts are bad when the hood no longer stays up reliably, sags or slowly drops, needs help lifting, or makes unusual noises during opening and closing—clear signs that the gas-charged supports have lost pressure or mechanical integrity. Understanding these symptoms in more detail can help you diagnose failing hood struts early, avoid safety risks, and plan timely replacement before the hood suddenly drops while you’re working under it.

What Hood Struts Do and Why Their Condition Matters

Hood struts—also called hood lift supports, gas struts, or lift shocks—hold your vehicle’s hood open and assist in lifting it. They are typically gas-charged cylinders with internal seals designed to maintain pressure over thousands of open–close cycles. Over time, temperature changes, wear, and corrosion degrade these components. When they fail, the hood may fall unexpectedly, creating a real safety hazard, especially if you or a mechanic are working in the engine bay.

Main Warning Signs of Failing Hood Struts

1. Hood Will Not Stay Open

One of the most obvious signs is a hood that simply won’t remain up without external support. This failure can show up suddenly or gradually worsen over time.

This list highlights specific ways an unstable hood indicates that your hood struts may be worn or failing, allowing you to recognize unsafe conditions before an accident occurs.

• Hood slowly sinks: After opening, the hood gradually drops a few inches, then more, and may eventually close on its own.
• Hood slams shut in wind: A moderate breeze or vibration from closing a door causes the hood to close because it’s no longer firmly supported.
• Needs a prop rod or stick: If you or your mechanic are improvising with a broom handle, metal bar, or other object to hold the hood up, the struts are no longer safe.
• Inconsistent holding: Some days the hood holds, other days it doesn’t—often related to temperature changes affecting weak gas pressure.

When the hood no longer remains fully open by itself, the struts have nearly always lost sufficient pressure or internal sealing, and continued use becomes both inconvenient and dangerous.

2. Difficulty Lifting or Heavy-Feeling Hood

Good hood struts do more than hold the hood up; they assist with lifting it. If opening the hood suddenly feels like a workout, it may signal failing struts.

This list explains how changes in the effort needed to open the hood can reveal early-stage deterioration in hood strut performance.

• Increased effort: You feel significantly more weight when raising the hood than you used to, especially in the last portion of travel.
• No “assist” near the top: Healthy struts usually help pull the hood upward near the middle or upper range; when this disappears, they’re weakening.
• Stiff then floppy motion: The hood may resist at first, then move too freely, indicating uneven internal gas pressure or worn seals.
• Needing two hands: If a previously easy, one-hand operation now feels safer with two hands, that’s a red flag.

A hood that feels heavier or lacks its usual assisted motion often reflects a gradual loss of gas charge; replacing the struts restores the original light, controlled lift.

3. Hood Opens Only Partway or Stops Mid-Travel

Some failing struts lose enough force that the hood no longer travels to the fully open position on its own, stopping short and creating tight working space.

The following points outline how partial or incomplete hood opening patterns can help you distinguish failing struts from simple mechanical obstructions.

• Hood stalls halfway: After you release it, the hood stops mid-range instead of rising to full height and may slowly sink back down.
• Won’t lock fully open: On vehicles where the hood “settles” into a stable top position, it no longer reaches that point.
• Relies on manual hold: You must keep a hand on the hood until you can wedge it open with another object.
• Different behavior side to side: If one strut is weaker, the hood may twist slightly as it opens and stop off-center.

When the hood won’t confidently reach and stay at its full open position, the struts are no longer performing their designed support role and should be inspected or replaced.

4. Visible Damage, Leaks, or Contamination on the Struts

A close visual inspection of the hood struts themselves can reveal obvious signs of wear or failure, especially around the rod and cylinder body.

This list describes visual clues on the struts that commonly indicate internal gas loss, seal failure, or physical damage that compromises performance.

• Oil or grease leakage: Wet, oily streaks along the strut body or on the shiny rod often mean the internal seals are failing.
• Rust or corrosion: Corrosion on the rod can damage seals each time the rod moves, accelerating gas loss.
• Pitted or scored rod: Scratches or pitting on the chrome rod can keep the strut from sealing properly, leading to rapid failure.
• Loose or bent mounting points: Weak brackets, cracked ball studs, or bent ends can make the hood unstable even if gas pressure remains.
• Dust buildup on wet areas: Dirt sticking to oily surfaces is a sign of slow, ongoing leakage.

Any combination of fluid residue, surface damage, or corroded mounts indicates that the struts are either already compromised or likely to fail soon under normal use.

5. Temperature-Dependent Performance

Because hood struts are gas-charged, their performance often changes with temperature—one of the more subtle but telling indicators of weakening components.

This list explains how variations between cold and warm conditions can help confirm that deteriorating gas pressure, rather than a mechanical obstruction, is behind hood-support issues.

• Fine when warm, weak when cold: In warm weather, the hood might just barely stay up, but in cold temperatures it drops quickly.
• More sag on cold mornings: You notice the hood slowly lowering only in low temperatures, especially after overnight parking.
• Requires extra push in winter: The hood needs more force to open at low temperatures, then improves slightly as it warms up.
• Progressive worsening across seasons: A marginal strut might first show symptoms in winter and then become unreliable year-round.

If hood-support problems are more pronounced in cold weather, it’s a strong indication that the internal gas pressure is already marginal and the struts are near end-of-life.

6. Unusual Noises During Hood Operation

Healthy struts operate quietly. New sounds while opening or closing the hood may point to mechanical wear or strain within the support system.

The following sound-related clues can alert you to worn or binding hood struts—or to mounting issues that often appear around the same time as strut failure.

• Clicking or popping: Noises as the hood moves may come from worn ball sockets at the ends of the struts or loose hardware.
• Grinding or scraping: If the rod is no longer moving smoothly, internal damage or external contamination may be present.
• Metal-on-metal creaks: Loose or bent brackets, or a failed strut forcing one side to do all the work, can cause flexing and creaking.
• Sudden clunk as it drops: When the hood loses support mid-travel, it may drop until it hits the latch stops with a noticeable thud.

While noises alone don’t prove bad struts, they often accompany visible wear and poor holding performance, helping confirm that replacement is warranted.

Simple At-Home Tests for Hood Strut Health

1. Static Holding Test

The most basic test is to open the hood fully and observe how it behaves over time and under light disturbance.

This list outlines straightforward steps any driver can take to safely evaluate whether the hood struts are still providing enough holding force without special tools.

• Open the hood fully: Engage the secondary safety catch and raise the hood to its normal full-open position.
• Let go carefully: Stand to the side, not directly under the hood, and gradually release your hands while watching for movement.
• Tap or gently shake the vehicle: Close a door or lightly nudge a fender to simulate normal vibrations.
• Observe for at least 30–60 seconds: Any slow lowering, wobbling, or movement suggests weakened struts.

If the hood cannot maintain a stable, fully open position during this simple test, it’s usually a strong sign that the struts no longer provide sufficient support.

2. Partial-Open Balance Test

Testing at intermediate positions can reveal weaknesses that aren’t as obvious at the extremes of travel.

This list details a careful step-by-step check at mid-range hood positions, which can highlight uneven or marginal strut performance before complete failure occurs.

• Open hood halfway: Raise the hood to about 50–70% of its normal open range and pause.
• Release gently: Again, stand slightly aside and see whether the hood rises, falls, or stays put.
• Note direction and speed: A healthy system often continues to rise slowly; weak struts may let it sink immediately.
• Compare multiple attempts: Inconsistent results suggest struts on the edge of failure.

When the hood cannot hover or continue upward from partial positions without quickly falling, the struts are typically too weak for safe, long-term use.

3. Side-to-Side Comparison (If Dual Struts)

Many modern vehicles use a pair of hood struts, one on each side. Often, one fails before the other, creating uneven support.

The following checks help you spot asymmetric wear when your hood is equipped with two struts, which can twist the hood and overstress hinges if not corrected.

• Watch hood alignment: As you raise and lower the hood, look for any twisting or tilting to one side.
• Check for uneven speed: If one side appears to move more quickly or take more load, that strut may be weaker.
• Compare rod cleanliness: A strut with more dirt build-up on a slightly oily rod often indicates leakage and weakness.
• Gently press near each strut: With the hood open, carefully press down near each side; a weaker strut will allow easier movement.

Differences between the left and right sides strongly suggest that at least one strut is failing, and best practice is usually to replace them in matched pairs.

Common Causes of Hood Strut Failure

1. Age and Normal Wear

Most hood struts are consumable parts. Even under ideal conditions, internal gas and seal materials degrade with time.

This list highlights how normal use and the passage of time gradually weaken even well-maintained hood struts, making eventual replacement inevitable.

• Seal fatigue: Rubber or synthetic seals harden and crack, allowing gas to escape.
• Gas permeation: Small amounts of gas naturally seep through seals over many years.
• Cycle fatigue: Frequent opening and closing stresses internal components.
• Typical lifespan: Many hood struts last 5–10 years, but high use or extreme climates can shorten this.

Even without abuse, time alone is enough to wear down hood struts, so older vehicles frequently need replacements as routine maintenance.

2. Environmental and Usage Factors

Real-world conditions often accelerate wear, especially in harsh climates or demanding operating environments.

The points below show how specific environmental conditions and usage patterns can hasten hood strut deterioration beyond normal aging.

• Extreme temperatures: Very hot or very cold weather stresses seals and changes internal pressure.
• Road salt and moisture: Corrosion from salt, humidity, or frequent washing attacks metal surfaces and mounts.
• Dirt and debris: Grit on the rod surfaces can abrade seals as the strut cycles.
• Frequent lifts: Commercial or fleet vehicles with many daily checks wear out struts faster.

Understanding how climate and usage affect these components can help you anticipate earlier replacement intervals and avoid surprise failures.

3. Improper Handling or Accidental Damage

Hood struts can sometimes be damaged during unrelated repairs or through rough use of the hood itself.

This list explains how accidental impacts or incorrect procedures can damage hood struts prematurely, even on relatively new vehicles.

• Forcing the hood shut: Slamming or leaning hard on the hood can strain mounts and bend brackets.
• Using struts as handholds: Grabbing or pulling on the strut body or rod can damage internal components.
• Improper tool use near struts: Wrenches or pry bars can nick or scratch the rod when working in the engine bay.
• Collision damage: Even minor front-end impacts can misalign hood hinges and put unusual loads on the struts.

When struts fail unusually early on a newer vehicle, it’s worth considering whether external damage or misuse played a role.

When to Replace Hood Struts—and Safety Considerations

Deciding It’s Time for New Struts

Driving with weak hood struts does not affect vehicle movement, but it does create significant safety risks whenever the hood is open.

The following indicators can help you decide when replacement is no longer optional but necessary for safe access to the engine compartment.

• Hood can’t stay open without support: Any reliance on improvised props means replacement is overdue.
• Noticeable drop when disturbed: If bumps or wind regularly make the hood move, it’s unsafe.
• Documented leakage or damage: Visible oil, corrosion, or rod damage is strong justification for new struts.
• Routine maintenance access: If you frequently check fluids or work under the hood, reliable support is critical.

As soon as you no longer trust the hood to stay safely open on its own, it is prudent to schedule replacement rather than wait for a complete failure.

Basic Replacement and Professional Help

On many vehicles, hood strut replacement is a straightforward job, but it still requires caution and the right tools.

This list outlines general considerations for replacing hood struts and deciding whether a do-it-yourself approach or professional service is more appropriate.

• Support the hood securely: Always use a strong prop or helper; never remove struts while relying on them for support.
• Replace in pairs when applicable: Matching new struts on both sides ensures balanced support and longevity.
• Follow vehicle-specific guidance: Some models have clips, torque requirements, or trim pieces you must handle correctly.
• Consider shop replacement: If you’re unsure or uncomfortable, a repair shop can typically replace hood struts quickly at modest labor cost.

Proper installation restores full, stable hood operation and reduces the risk of injuries or damage during engine-bay work.

Summary

Failing hood struts reveal themselves through clear signs: a hood that won’t stay open, feels heavy to lift, opens only partway, or shows visible leaks and corrosion. Temperature-sensitive performance, unusual noises, and uneven side-to-side motion further confirm that the supports are weakening. Simple at-home tests—observing whether the hood holds steady when fully or partially open—can quickly reveal whether the struts are still safe.

Age, environmental exposure, and occasional accidental damage all contribute to hood strut failure, making replacement a normal part of vehicle maintenance, especially after several years of use. Once you notice that the hood is no longer reliably self-supporting, replacing the struts—ideally in pairs on dual-strut setups—is the safest and most effective way to restore secure, predictable hood operation.

What sound does a bad strut make?

A bad strut can make a variety of sounds, including a clunking, banging, or knocking noise, especially when going over bumps. You may also hear a squeaking or creaking sound, particularly when turning, or a metallic grinding noise from the strut assembly. 
Types of sounds and what they mean

• Clunking, banging, or knocking: This is often caused by the strut bottoming out or by loose components in the strut assembly. It is most noticeable when driving over bumps. 
• Squeaking or creaking: This typically indicates that the strut bushings are struggling to provide their damping function. You may hear this more at lower speeds or when hitting larger bumps. 
• Metallic grinding or squeaking: This noise can occur when turning and may point to a bad strut mount bearing or other worn components. 
• Rattling: This can also be a symptom of a failing strut, especially when driving over rough roads. 

Other signs of a bad strut
Besides the sounds, other symptoms of bad struts include: 

• A rough or bouncy ride, even on smooth roads
• Uneven tire wear
• Reduced handling and braking performance
• Visible signs of hydraulic oil leakage from the strut

What are the symptoms of bad struts?

Symptoms of bad struts include a bouncy or overly harsh ride, nose-diving when braking or squatting during acceleration, excessive body roll in corners, and unusual noises like clunking or squeaking. Other signs include uneven tire wear, leaking fluid on the struts, and a shaking steering wheel.
 
Handling and ride quality 

• Bouncy or bumpy ride: The vehicle continues to bounce multiple times after hitting a bump instead of settling down quickly. 
• Excessive body roll: The car sways or leans more than usual when turning corners. 
• Nose-diving: The front end dips excessively during hard braking. 
• Rear squat: The rear of the vehicle sags or squats when you accelerate. 
• Decreased steering control: You may feel less stable or have a harder time steering, especially during sharp turns or in windy conditions. 

Noises

• Clunking or knocking: A hollow sound that can happen when going over bumps or when the suspension moves suddenly.
• Squeaking or grinding: Can indicate worn-out strut mounts or bearings, especially when turning.
• Creaking or groaning: A sign of worn-out bushings within the strut assembly. 

Other indicators

• Fluid leaks: Leaking hydraulic fluid on the outside of the strut or in the wheel well is a clear sign of failure. 
• Uneven tire wear: Look for “cupping” or “scalloping” on your tires, which happens when they aren’t making even contact with the road. 
• Vibration: A shaking or vibrating steering wheel, especially on smooth roads, can point to worn struts or shocks. 
• Longer stopping distances: Worn struts reduce your car’s ability to stop efficiently. 

How to tell if hood struts are bad?

Here are three signs of bad hood struts so you know to swap them out promptly.

1. You were one of the first hood strut lift kit adopters (struts are getting old!)
2. You hear squeaking or other noises when you open and close the hood.
3. The hood fails to stay open, whether it slowly closes or falls quickly.

Why do hood struts fail?

Hood struts fail primarily due to wear and tear over time, causing seals to degrade and leak the internal pressurized gas and hydraulic fluid. Other causes include physical damage like corrosion or bending from impact, and environmental factors like temperature changes, which can degrade seals and reduce gas pressure.
 
Reasons for failure

• Seal and gas leakage: The seals that contain the pressurized gas and hydraulic fluid will eventually wear out. As the seals fail, gas leaks out, causing the strut to lose its ability to hold the hood up. 
• Physical damage:
  • Corrosion: Moisture and road salt can cause rust on the piston rod. The resulting rough surface can damage the seal, leading to leaks. 
  • Impact: Forcing the hood shut, incorrect installation, or other physical impacts can bend or damage the strut, preventing it from working smoothly. 
• Age and usage: Even without obvious damage, normal wear and tear from repeated opening and closing, combined with temperature fluctuations, will cause the internal components to fatigue and the struts to lose pressure over time. 

You can watch this video to learn how to replace hood struts: 59sJack FletcherYouTube · Jan 8, 2023
Consequences of failure

• Sinking hood: A failing strut may cause the hood to slowly lower on its own, and eventually, it will not stay open at all. 
• Sudden failure: In some cases, a strut can fail suddenly, causing the hood to crash down, which can lead to injury or damage to the vehicle.