You'll want to give your Datsun 240Z some extra love and care now that it's over 50 years old! I get it - it's a legendary and classic vehicle that turns heads everywhere you go. But you need to watch out for a few trouble spots.
You might see your 240Z acting up in ways that you didn't expect! The cooling system loves to act all finicky. Those old electrical systems can drive you crazy with unexpected problems. Plus there's some other parts that tend to wear out faster than others too. The positive news? Once you know what usually breaks, you can catch the problems early and keep your Z running like new.
Think of this as your useful heads-up on what typically goes wrong with these beautiful machines. You'll learn about the specific parts that like to fail. You'll see why they fail and what you can do about it.
Ready to check out the problem areas? Let's jump right in and look at the spots where your Z might need some extra attention!
Disclaimer: This article is authored by a member of the Skillard community and reflects their personal views, not necessarily those of Skillard. We welcome your feedback and corrections in the comments to help us continually improve this content.
Table of Contents
Rust and Body Corrosion
Rust will destroy your Datsun 240Z if you're not careful! You'll probably see this destructive problem when it's already too late. You'll spend a lot of money on repairs. Your Z car is especially open to rusting because of its age and the specific way Datsun made it back then.
You should watch out for rust in several spots on your 240Z. Water loves to find and eat away at the frame rails and floor pans. It also attacks where body panels meet! The area around your battery and fuel door will rust out pretty fast too. Take a close look at your wheel wells and the bottom of your doors. That's where rust typically shows up first.
Where you live can affect how fast your Z car will rust. If you're living near the ocean or in regions where they dump salt on the roads, your car will rust much faster. Rain and snow will speed the process up too. You'll need to work extra hard to keep your Z rust-free in these tough locations.
You can fight back against rust. But you'll need to stay focused on it. You should wash your car regularly to get rid of the corrosive materials that cause rust. Z owners like to put coatings like POR-15 or Fluid Film underneath their cars to keep moisture away. Remember to seal up the sections where panels come together too.
Have you already spotted some rust? You should jump on it right away before it spreads everywhere! Sometimes you can fix small rust with a wire brush and some rust treatment chemicals. For severely damaged places you'll need to cut them out and weld in new metal. Some Z owners eventually give up and retire their cars when the rust gets too severe. These cars are over 50 years old now. Some have been kept in a garage and some have been kept in a bar. If it was kept in a barn, it's going to be a rust bucket!
Rust never stops coming after your vintage 240Z. Most surviving Z cars show extensive damage in their frame rails and floor pans. Rust loves to pop up around your headlights and fenders. It also attacks the hood cowl area. The front end support and passenger side of your car will probably need a lot of fixing too because of rust damage.
Transmission and Clutch
Your Z-car's clutch system can act up in ways that get in the way of changing. You'll see it first when the clutch pedal starts feeling mushy under your foot! When the clutch won't disengage you might struggle to change gears too.
Low hydraulic fluid typically causes these frustrating problems in your clutch system. Air bubbles can sneak into the lines and create similar problems. You should check your fluid levels and bleed the system to stay away from these problems.
Your master and slave cylinders need attention because they often fail. These parts might start leaking or completely stop working over time. When that happens you won't be able to use your clutch properly. You can get better results by replacing cylinders at the same time.
When you hear grinding sounds while changing it can spell serious trouble for your Z-car. Your throwout bearing or pressure plate could be on its way out. Your clutch disk could also be too worn down to work right anymore. These parts need to work together well.
You can spot problems early by staying on top of maintenance. Make sure you check the clutch fluid every couple of months. Keep your ears open for unusual noises during changes. See how your clutch pedal responds when you press it! Look into any changes in how the pedal feels or catches.
The transmission problems start with clutch problems. Your clutch could be slipping when you accelerate because the friction material is thin. When you have trouble changing it's probably your hydraulic system acting up! If you can't get into gear at all your slave cylinder has probably given up.
The promising news is that your 240Z's transmission holds up well if you take care of it. Most serious problems come from letting clutch maintenance slide or damaged parts. Your synchros might make changing tough - especially on cold mornings. Finding metal bits in your transmission fluid suggests something's wearing down inside.
System Radiator Leaks
Your 240Z's radiator can now quickly become a big headache if you don't catch the problems early on. You'll first see some small pinhole leaks creating in the radiator core. These small problems can snowball.
Watch out for coolant mysteriously vanishing from your system. You might spot green or orange puddles under your car after parking it. The temperature gauge will also start climbing higher than it should during your drives.
Your engine will start to overheat when the radiator fails (especially during hot summer weather or longer trips). You'll probably see your car losing power and running rough once it gets too hot. You should check for fresh coolant stains showing up near your alternator or suspension parts.
Don't wait too long to fix these problems. Your cylinder heads might crack or you could blow a head gasket. All that extra heat and pressure will probably damage other cooling parts like your water pump and thermostat.
Take a few minutes each month to check your cooling system. Look for any crusty deposits and stains around your radiator and engine bay. Make sure you're keeping an eye on your coolant levels between your regular service appointments too.
You'll need some equipment to track down exactly where a leak is coming from. Try pressure testing your cooling system to find problems you can't see. You can also use some dye tests to spot those tricky leaks that are hard to find.
When it comes to fixing your radiator you'll either need to patch small leaks or swap in a new unit. You might want to think about upgrading to a high-performance 240Z radiator while you're at it. These tough units will keep your engine cooler and typically last longer than the original parts.
Remember that your radiator isn't always the only component causing cooling problems. Your hoses could be worn out. Your water pump could be failing or you might have a leaky head gasket. Be sure to get everything thoroughly examined to catch all problems.
Electrical Wiring Problems
Your 240Z's electrical system runs like a tricky web and you'll probably run into some problems along the way. The previous owners may have messed with the wiring too. This makes everything even more confusing! You'll usually find questionable fixes like wire nuts or excessive electrical tape causing shorts. Even basic items like dirty connectors can hurt your car's electronics.
You need to watch out for water damage too. It's one of the biggest threats to your car's electrical parts. The wiper motor connector sits in a place that makes it easy for water to get in. Once moisture creeps into your connectors and terminals they can start to rust! When that happens your electrical parts won't get the power they need to work right.
Your headlights might suddenly go dark while you're cruising at night. The turn signals or brake lights could quit working without any warning. What starts as a small problem could put you and everyone else on the road in danger.
You'll want to keep a close eye on the battery system. When your car is sitting there you should see between 12 and 12.6 volts. If you rev the engine that number should jump to somewhere between 13.8 and 14.4 volts. Lower numbers than these probably mean you have electrical problems hiding somewhere.
Tracking down electrical problems takes some detective work. First you should check all your fuses and make sure their contact points aren't damaged or corroded. You can grab a voltage meter and start testing different parts of the system. Look at the wiring especially in areas where someone may have tried to fix it before.
Your dash wiring can be especially tricky since most electrical connections come together right behind your dashboard. This setup makes it tough to find what's going wrong. When your dash lights and gauges start acting up you'll probably need to dig into this network of wires. That small dashboard dimmer switch loves to cause problems with your instrument lights.
Suspension Component Wear
You'll see that your Z car doesn't manage quite as well as it once did. The suspension system takes a real beating over decades of use. The parts can wear down and break as these classic cars get older too!
Those rubber bushings throughout the suspension cause most of the problems you'll encounter. These cushions sit between the metal parts. They start cracking and falling apart from years of heat and stress. When your bushings go bad, your Z will feel loose and sloppy every time you take a corner!
Your shock absorbers won't last forever either on these vintage rides. Once they wear out you'll lose some control over how your car moves. The ride gets bouncy and unstable in no time. Watch out for the front end diving when you hit the brakes or the rear squatting down hard when you accelerate.
Corroded or worn-out spring mounts and perches can affect your ride height. You'll probably see your tires wearing unevenly first. That's typically the earliest indicator something's wrong with the springs. Those worn sway bar links make your car roll too much as you might now expect too.
Your Z will tell you about suspension troubles through the way it works with you. Maybe it pulls to one side or feels unstable in corners. You might hear some clunking noises when you hit bumps. Your steering could feel disconnected from what's happening on the road.
Take a close look at your suspension parts to spot problems early. Search for cracks in the rubber bushings and check if your shocks are leaking. Move the control arms and tie rods to feel for loose play. Keep an eye on how your tires are wearing.
Modern parts can improve your suspension setup completely. Performance bushings will outlast the original rubber ones by many years! You can install an adjustable coilover system for enhanced handling. New sway bars and links help keep your car flat when you're pushing it hard.
Focus most of your attention on the front suspension. Take a look at those strut towers for rust damage. Give the control arm bushings and ball joints a complete inspection. Make sure all your suspension mounting points remain solid and rust-free.
Brake System Maintenance
Your Datsun 240Z's brake system needs extra attention since it has a few parts that commonly break down. You'll see that your brake pedal feels soft when the master cylinder starts leaking inside. This happens because the seals inside naturally wear out over time.
You might run into trouble with leaky and problematic rear wheel cylinders. The air out of these cylinders can be a real challenge. This makes repairs quite frustrating. The brake lines and rubber hoses like to get old and start leaking too.
Air bubbles in your brake lines are dangerous when you're driving your 240Z. These bubbles can sneak in through worn-out seals or from poor maintenance. You'll know you have air in there when your brake pedal feels spongy. Make sure you bleed your brakes to prevent this.
Check your brakes every month. Give your master cylinder and wheel cylinders a thorough check for fluid leaks. Look for wet places or drips around your brake parts. Remember to keep your brake fluid at the right level in the reservoir.
Pull your car off the road if you spot brake fluid leaks or feel your pedal going soft. You'll need to fix those leaks before bleeding the system. Sometimes you'll have to take the master cylinder off to get an expert bleeding done on the bench. This helps remove stubborn air bubbles that won't come out otherwise.
Earlier 240Zs come with another issue - the brake warning switch typically gives out. This switch monitors your brake pressure. Finding a new one now is like looking for a needle in a haystack. That's why 240Z owners change or skip this part altogether.
Stay on top of your brake maintenance to avoid scary brake failures in your 240Z. When those wheel cylinders start leaking, replace them right away. When your master cylinder shows signs of internal leaks, rebuild or replace it. Remember to check your brake lines and hoses every time you change your oil.
Build Your Dream Car
You can put loads of your time and energy into caring for your classic car. It's worth every single second that you spend tinkering in the garage! Each one of these beautiful machines has its own personality and quirks that make it one-of-a-kind. You'll find it much easier to keep your vintage ride in great shape once you learn what problems to watch out for and how to fix them.
You might feel a bit anxious when you start to think about the problems that could pop up! But remember this - even the most knowledgeable and experienced classic car experts started as complete beginners. A big part of getting started is to jump in and start learning how to preserve these remarkable machines. This helps future car lovers enjoy them too. Maybe you have already spotted some warning signs in your car? Or maybe you have run into some hard situations while working on your classic Z?
At Skillard, we recognize how deep the connection is between you and your classic Datsun. That's exactly why we pour our hearts into making exceptional custom parts specifically for Z cars.
We create parts like our expertly-designed bumpers and our innovative aluminum door cards. Our center consoles and spoilers help make your ride look better and perform stronger.
Want to freshen up your Z and make it even more spectacular? Head over to Skillard.com and check out our full lineup of parts. You'll find exactly what you need to make your dream car a reality!
