Aside from Japan, R31 Nissan Skylines were produced in Australia in the late 1980s to circumvent the stringent import laws of the country at that time. Available locally in sedan and wagon body styles, these Aussie Skylines were powered by the RB30 engine, which is Nissan-speak for an inline-6, normally aspirated engine with a 3-liter displacement. Horsepower for this engine type was rated at 155.
At this point, there is little hope for getting a mint condition vehicle when you buy a used Nissan Skyline R31. These cars would be three decades old or more and would interest enthusiasts more for their historical value than any other reason. Modifying the RB30 by installing a twin cam head and turbo system can see horsepower boosted to more than 450, but the cost would be prohibitive, with the engine losing longevity in the reliability department. But some people still want to buy a used Nissan Skyline R31 for various reasons, so here is a list of things to look for.
1. Rust is any car’s enemy, more so with older cars. In the R31, rust-prone areas include the roof area near the windscreen, door sills and frames (specially at the bottom), the tail light areas and beneath the rear spoilers. Empty the trunk of the car and look for evidence of rust there. While you’re at the rear of the car, check the tail lights and their housings for cracks. 30-year old plastic tends to fade and become brittle. It’s also fairly common for water to leak inside the headlights and tail lights.
2. Inside the car, check the dash lights when you start the car. Check that the gauges and other instruments work. Operate the switch gear to see if the circuits they’re connected to still work. These include the aircon vents, door locks, the rear window defogger and roof and door lights. Check the general condition of the interior. Are the seats firmly anchored? Are the bottoms still supportive? Although it’s not a known issue, it’s also a good idea to check under the carpet to inspect the floorpan for rust.
3. Broken exhaust manifold studs are a known issue with the RB30 engine, as well as a slightly ticking sound from the top of the engine. These are caused by the lifters and are not a cause for concern, unless it’s unusually loud. As with any engine, check the sides and bottom of the engine for excessive leaks. A clean or wiped underside engine sump or tray is a warning sign. The engine coolant should also be free of rust, or worse, evidence of oil. If the car has an automatic, the oil there should be clean and be free of metallic particles. A common component that fails is the crank angle sensor plug due to corrosion in the plug area. Short of a teardown, a very good indicator of an engine’s condition is to conduct a pressure test. All cylinders should test within a few psi of each other.
To be sure, a person who intends to buy a used Nissan Skyline R31 will find some issues with cars these old. It is up to the person who wants to own this classic Japanese car to decide if what he finds is enough to purchase the car or not.