When buying a 200SX, here are a few things you should have a good look at before buying and to have in your mind when discussing the price.
It is very common for the wing-mounted intercooler to have cracks in the piping. The pipes are made of an aluminium alloy and cracks form close to the radiator. Symptoms are lumpy idle and erratic acceleration. Check by removing the passenger side wheel (UK) and the plastic arch liner and closely inspecting the intercooler. Second hand ones are pretty easy to come by as most owners replace them with either an upgraded wing-mount or more preferably a front-mounted intercooler.
- Turbo gaskets
These commonly fail at the turbo-to-exhaust-manifold joint, but can also fail at the turbo-to-elbow joint as well. If one fails it is always worth replacing both as the major cost element is the time to remove the turbo. First symptoms of a failing gasket are a whistling noise on boost made by the escaping gasses. Major gasket failure makes the car sound like a tractor. This is a costly repair as it takes an experienced mechanic between three and five hours to remove and refit the turbo. Most owners take the opportunity to fit braided coolant and oil feed lines to the turbo whilst it is off as it makes the repair easier the next time the job is done. So, while you're looking in that area check that the pipes around the turbo are leak free.
Failing turbo oil seals are often seen as blue smoke in the exhaust as the oil is burnt on revving. If the car has a boost gauge fitted, check the readings during a drive (you won't see a positive pressure if you just rev it stationary). You should also see a negative pressure of around -20mmHg at idle if there are no major air leaks.
- Fuel pump
The original fuel pump seems to fail with dismal regularity at about 65,000 miles so check the mileage and/or receipts for replacement. The pump is also just about okay for a standard car, but if you are considering modifying the car at all, then you should really consider an uprated pump and most owners replace the standard even if it hasn't failed. There are unfortunately no warning symptoms, they just stop one day.
- Variable Valve Timing
The VVT is a piece of hydraulic trickery that alters the timing of the valves at higher engine revs. As the VVT valve wears you can get a distinctive rattling noise with half-warm engines. Symptoms: start the car and engage 1st gear, then listen for the noise as you lift the clutch pedal. This, despite the noise is absolutley fine and causes no damage. It's the result of the oil ways only filling when the gears are engaged. It is a costly part to replace and unecessary unless the noise is very loud and occurs all the time.
- Oil changes
As this is a turbo car it should really have oil changes every 6000 miles, with a good quality oil. Look for receipts or a service schedule. Symptoms of abuse: rattling top end due to the spray bars that lubricate the overhead cams being blocked - take the oil filler cap off and look for signs of oil flow. Look also at the dipstick and check it is not overly thin or has signs of water (looks like mayonnaise). Don't worry of the oil is black - it's meant to be.
The SR20DET engine is a robust lump and can easily cope with greater than 100,000 miles so don't be especially worried by high mileage. Do check for obvious oil leaks although it is fairly common to have some small signs of oil at the front.