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The Datsun 240Z shows its heritage in ways many other classic cars just can't match. You'll see it immediately when you sit behind the wheel - the long hood stretching out in front of you, those narrow window frames surrounding you, and the distinctive sound of the raspy inline-six engine. These elements help you understand within seconds why this sleek coupé left European and American manufacturers impressed back in the early seventies. Time changes things, though. After many years of heat cycles, worn gaskets, and questionable fuel quality, the car slowly loses that sharp throttle response and tight steering that made automotive journalists so excited. Your Z doesn't have to decline this way - it just needs you to listen to what it's telling you.
The engine deserves the occasional once-over, too. The L24 will run at its best when you keep the valve clearances correct and make sure the oil actually reaches that overhead cam. A faint ticking sound at idle may seem minor. But ignore it, and those cam lobes will wear themselves completely flat. Catch this early, and you can fix everything in a single afternoon with just a feeler gauge while enjoying your coffee. The same idea applies to the entire car. The dampers slowly lose their effectiveness, rubber bushings gradually soften, and carburetors drift out of sync with each other.
Every small change happens so gradually that you might adapt to them without realizing anything has changed. If you put your Z up on stands twice yearly to check everything, shake the suspension parts, adjust those SU carburetors, and write down what feels different from your previous check, your maintenance list will stay small and manageable.
Let's get into it together!
Table of Contents
The Factory Maintenance Schedule
You need to have the mindset of a 1970s service manager when caring for your 240Z, mainly since these classic cars can spend more time being polished in a garage than cruising down the road these days.
Frequent oil changes are still needed for your 240Z because Nissan designed these vehicles with 3,000-mile intervals in mind since additive packages in the 1970s broke down much faster. The L-series engine in your car still needs this same level of protection. While modern synthetic oils usually last longer in newer vehicles, your engine has a flat-tappet cam that specifically needs zinc additives for protection. Many modern "extended life" oils have almost no zinc at all, which can damage your engine. You should choose a high-zinc blend and follow those shorter change intervals - this small investment helps keep your lifters running quietly even when you're pushing the engine to 6,000 rpm.
The cooling systems in your 240Z age continuously, even during periods when the engine sits idle. The glycol compounds in your coolant slowly lose their ability to fight corrosion as your car waits through winter months in storage. This natural degradation explains why following the manual's recommendation for coolant replacement every two years makes practical sense. If you drain, flush, and refill your cooling system according to this schedule, you can prevent the frustrating experience of scale deposits breaking loose and clogging your radiator when you take the car out for the first drive on a beautiful spring day.
Distributor shaft maintenance prevents both spark scatter and rough idle problems in your 240Z. You should apply a small amount of grease to the cam heel at the beginning of each driving season to make sure advance weights move without restriction, and your engine's dwell stays steady. The greasing procedure only takes a minute or two of your time, though locating your 8 mm wrench in the toolbox might actually take longer than the maintenance itself. When you skip this basic step, it can cause frustrating, hard starts that you might wrongly diagnose as carburetor-related problems.
Valve lash adjustments appear difficult but become straightforward once you attempt them. The process is about sliding a feeler gauge under the rocker when the engine reaches top dead center, then making your adjustment and securing it in position. While you might plan to dedicate an entire afternoon to this job, most owners finish it before their coffee even has a chance to cool down.
Time passage affects your classic 240Z much more than accumulated miles on the odometer. Your weekend cruiser will need fresh fluids and lubricants based primarily on how many months have passed, not how far you've driven. Even cars that barely add new miles each year still need consistent maintenance to stay in peak condition.
The Most Common 240Z Maintenance Mistakes
When you own a Datsun 240Z, it comes with a set of responsibilities that most enthusiasts only learn about through experience. You can see these stories pop up in restoration forums all of the time. Someone buys a Z and forgets to check their coolant hoses regularly for a few years. Then suddenly, when they're driving on the highway, an old hose cracks and begins leaking everywhere.
Your vintage Z needs regular care for its hydraulic systems to stay running well. You should check your brake and clutch fluid levels at least every couple of months. If you feel your brake pedal is soft or less responsive when you press it, that's usually your first sign that the master cylinder is starting to have leaks before they turn into a safety concern.
Your transmission gives you hints if you pay attention to how it feels when you drive. These early indications usually point to hydraulic system problems that will only get worse if you ignore them. If you take care of these small problems right away, you'll save yourself from dealing with bigger repair bills down the road.
Rust prevention is probably the most ignored part when you own a Z. Over time, water can seep into the floor pans and rocker panels of your car. What starts as just a small bit of rust now can develop into serious structural damage that's much harder to fix in the future.
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Most Z owners love the engine power their cars deliver but don't remember to take care of their carburetors correctly. When throttle mechanisms become unresponsive, you'll start to see difficulty starting your car and decreased performance. You can prevent these problems by adding a quick lubrication step whenever you change your oil.
People usually put off valve adjustments far too much with these cars. This delay causes uneven wear patterns in your engine that lower its efficiency and produce that obvious ticking sound you might hear. If you check your valve clearances on the recommended schedule, you'll help keep your engine healthy for years to come.
When air bubbles get trapped in your brake lines, you have an unsafe driving situation. Regular bleeding of the brake system makes sure your Z can stop reliably when you need it to.
What Parts Should You Keep On Hand?
When you use the right parts for your 240Z, it makes a real difference in how well it runs. The modern oil filters you can buy now capture significantly more dirt and debris than what came with the car originally. These newer filters help keep your engine much cleaner between your regular oil changes and can add years to your engine's lifespan.
Your spark plugs need some extra attention when you're doing maintenance. Most experienced Z owners recommend NGK BP6ES plugs because they work very well in these classics. You'll get reliable performance without spending a fortune on expensive alternatives.
Engine oil choice matters a lot for your vintage car. Try a high-zinc 10W-30 formula designed specifically for older vehicles like yours. That type of oil gives your flat-tappet camshaft and other original parts protection that standard modern oils don't. The zinc forms a protective layer that stops metal parts from wearing against each other.
Your brake system needs particular care during maintenance. Be sure to only use DOT 3 or DOT 4 fluid that comes from completely sealed containers. I know someone who put the wrong brake fluid in his Z, and within just a few months, all of the seals started to fail. He ended up with an expensive repair that could have been avoided.
It can be hard to find reliable replacement hoses and belts for classic Z owners. Specialty suppliers like MSA and Motorsport Auto sell rubber parts that fit exactly like the originals but are made with better materials. When you install your radiator hoses, you won't have to worry about them splitting open after just a couple of years like most off-the-shelf parts do.
Air filter technology has come a long way since your 240Z was manufactured. The replacements available now catch more dust particles while still allowing your engine to get plenty of air. That means your carburetor will stay in better condition, and your engine can "breathe" much more efficiently during your drives.
Modern Upgrades Worth Considering
Your Datsun 240Z has plenty of modernization options that improve performance without losing its classic character. Electronic ignition kits are a favorite upgrade with Z owners for a practical reason. The Pertronix Ignitor kit converts your car's finicky points system into a reliable setup that fires up every time you turn the ignition.
Lots of Z enthusiasts experience fewer maintenance hassles after making the switch to electronic ignition. One owner documented great results with cold weather starting after the installation. His previous frustrating five-minute morning routine became just a quick turn of the ignition.
Suspension upgrades are another great way to update your classic Z. Fresh bushings paired with quality shocks can improve how your car performs through corners and curves. These component upgrades usually run between $300 - 600 for reliable parts and deliver real improvements in how your car responds to steering inputs.
A well-designed exhaust system deserves consideration as you plan your modifications. When you pair a quality header with a well-designed exhaust, you can improve your engine by 15-20 horsepower while creating that distinctive growl that makes other drivers look your way at stoplights.
Consider what matters most for your particular driving habits when planning modifications. Enthusiasts who like winding roads might want to prioritize handling upgrades first, whereas those driving their Z more frequently will benefit from reliability improvements as their starting point.
Remember that aftermarket parts don't always play nicely together without more adjustments. Some parts need extra adjustments to work well with your particular setup. Z community forums can save you from expensive errors that fellow enthusiasts have already learned about the hard way.
Build Your Dream Car
We've seen how following your factory maintenance schedule helps you prevent unexpected breakdowns that happen when you miss needed service items. The right maintenance supplies make a big difference, too, as they save you time and frustration when you're working on your car. These cars had solid engineering for their era, and well-selected modern upgrades can improve reliability and performance without losing the character that makes these Z cars unique.
I've found through my restoration projects that taking your time pays off when you're maintaining these beautiful machines. You can see how passionate Z owners are about doing proper work by their excitement over recent developments like the newly available service slide films released earlier this year. Those 5,000-mile service intervals might seem routine. Each time you finish a maintenance job on your Z, you'll feel that personal connection to the car's heritage while making sure it stays ready for weekend drives.
The right parts matter just as much as proper maintenance when improving your Z experience. At Skillard, we have become the preferred supplier for lots of enthusiasts looking to upgrade their Datsun cars. We sell custom-made parts for the 240Z, 260Z, 280Z, and other Datsun models and give you plenty of options if you want a full restoration or just targeted improvements. We make everything from bumpers and aluminum door cards to functional center consoles and aerodynamic spoilers - all designed to respect the original styling while adding modern touches.
When you maintain and upgrade your classic Z, it becomes a continuing process that brings satisfaction from the work itself and the results you achieve. You'll find that joining Z car forums or studying the 1970 service manual gives valuable tips for your maintenance plan. Just last month, a fellow enthusiast told me how he tackled his first valve clearance adjustment with factory specifications and saw an immediate improvement in engine performance. Whether you plan a full suspension refresh or just stay on top of scheduled oil changes, each maintenance step brings you closer to the best driving experience.
Take some time to check out our catalog at Skillard.com to find the perfect parts for continuing your Z car adventure.
