Z32 buyer guide
Points to Remember When Buying a 300ZX
Buying a car can be a stressful experience, whether itís new or used, sports car or family vehicle. There are plenty of things that need to be checked out regardless of what make and model car youíre buying, and then there are the special points to consider when looking for a 300ZX that may point out why that deal of a lifetime is too good to be true. Always do the same things that should be done when buying any car: look for signs of rust, accident damage and bad bodywork, or poor maintenance. If the maintenance records are well kept, it might be wise to try to locate one of the carís previous owners and see why they got rid of it and if it had any unusual issues, anything that might make you think twice about buying the car. This is all homework that should be done when buying any car, however the following are things that should be checked out in particular on the 300ZX: Be sure that the VIN number on the dashboard and the VIN number stamped into the firewall are matching. If not, this should set off a red flag in your head that the car may have been stolen or in some sort of accident.
- Know what youíre looking at. Often someone will be selling a car that they believe is, for example, a 1990 when itís really a 1991. When in doubt, check out the VIN. The 10th digit designates the production year.
- Always try to get access to the car first thing in the morning before you buy it. That way the engine is completely cooled down and a warmed up engine cannot mask issues like weak batteries and starting problems.
- Check underneath the car to see if the front frame rails have been damaged in any way. If they are bent, usually this can indicate some sort of minor accident, such as curb mishaps. It would be best to have a professional take a look at the alignment to make sure that it can still be adjusted to fall within manufacturerís specifications.
- If the car has maintenance records, check to see if the timing belt has been changed recently. If not, or if the records donít seem to make sense, plan on changing the timing belt as soon as possible.
- Take a look and see if the corrective work was done to the injection system on the car, or if there has been any sort of engine fire. Fire damage would be easy to spot, check for melted insulation on the underside of the hood and also be wary of any melted wires. If the injector work has been done, there should be some components that may look newer, and also the connections to the injectors will be spliced into the wiring harness. If the work has not been done, make plans to have it done as soon as possible.
- Check and see if all of the glass in the car is the same. If some pieces are different, it may be an indicator that the car was in an accident or that the window was broken out by vandals or thieves attempting to steal the carís contents or the stereo system.
- When you take the car on a test drive, try taking it through a brushless car wash. The high-pressure water jets are useful for detecting leaks, which are common where the door glass and the T-Tops meet the roofline.
- When test driving the car, take it to a vacant lot where you can put the car through its paces. Accelerate full throttle and check for smoke coming from the rear. Swerve a couple of times and brake sharply. If the wheel shimmies when you brake, be prepared to have a potential issue with a brake rotor, ball joint, steering linkages or alignment issues. Stock rotors on the '91+ Z's can warp quite easily. If you have a chance to take the wheels off of the car, put two lug nuts on without the wheel and then attempt to forcibly remove the rotor from the car. If the rotor feels loose, then something is amiss and further inspection would be necessary to determine the cause of the problem.
- Be sure of your reasons for wanting the car. If youíre going for performance, a twin turbo is a must-have. Turbo swaps can be done, however a great deal of time and money will be spent replacing many non-turbo parts.
- Remove the oil filler cap and check the underside of the rocker arm cover for any imperfections or particles suspended in the oil. Black oil does not always mean trouble, just that the oil is in need of changing. It would also be advisable to check the oil filter; a generic filter may indicate that the owner doesnít do his own maintenance and may have cut corners on some parts. Cheap parts now can cause many problems later.
- If possible, check out the engine, transmission and differential mounts to see if they have separated. Typically this will not cause a problem, but may result in unusual noises and be something you would have to correct later on, which can be an inconvenience.
- Another telltale sign of a minor accident can be the condition of the air conditioning condenser. Look under the front bumper towards the radiator. The condenser is just in front of it, and should be flat and straight. If the condenser is warped, it doesnít necessarily mean that it doesnít work; the car may have had a minor accident.
- Leave the car idling and take a walk behind it to smell the exhaust. Any unusual smells or oddly colored smoke can indicate tuning problems. If it smells of rotten eggs, more than likely the catalytic converter is either worn out or stopped up. Bluish smoke is an indication that oil is being mixed in the cylinder, white smoke can be indicative of coolant (often a head gasket issue), and blackish smoke indicates a rich fuel mixture. Also listen to the engine and note any misfires or partial misfires, as these may indicate worn ignition components.
- Manuals can have problems with the hydraulic system that operates the clutch (leaks or air in the system, causes slipping clutch or soft pedal). Also Make sure the clutch bearings aren't making alot of noise. They can make a little noise for 30K miles or more. But alot of noise signals an upcoming clutch replacement.
- The brake master cylinder on '89,'90-'91 cars will begin leaking (at around 40-50K miles). The new part is redesigned and is supposed to be better.
- Knock or detonation-sensor (or actually the wires to the sensor) is prone to failure.
- Cars produced before 7/90 may have problems with defective valves, They will make a tapping noise after a while. TT's with engine-numbers below 619550 or NA's with numbers below 777599 may be subject to this problem.
- The Power Transistor Unit (PTU) which controls spark to each coil pack is prone to failure and earlier models were actually voluntary recalled in the US.
- On the 1990 model, Leaves and other debris can collect in the evaporator housing, clogging the drain and causing water to leak into the passenger footwell. A revised cowl screen is required.
- O2 sensors can cause problems with fuel economy and are also sometimes difficult to diagnose.
- Driveshaft center carrier bearings seem to fail between 70K and 100K miles
- Watch the boost-gauge (TT's only) during idle. The needle should be to the far left this shows that the engine is in good shape. If the needle is closer to the middle of the gauge during idle, it might indicate the engine has compression problems or there are vacuum leaks in the system. (usually comes together with rough idle)
- Durring the test drive, oil pressure should be between 30 and 60 psi during normal driving and at 10-15psi at idle.
- TT's are a lot more prone to overheating problems than NA's Take the care for a long test drive - check the gauges in car and look in the near side wheel well for signs of coolant expulsion
- Try to avoid automatics from '89/'90/early '91, especially higher mileage ones the early automatic-gearboxes have overheating problems, due to a design-flaw).
Sources Used on This Page:
- 300ZX.CO.UK's Z-BUYING GUIDE
- 1990-1995 Nissan Factory service Manual