The only way to inspect a used vehicle is to use a checklist. Here are some key points:
Your inspection should also include the following:
• A service record is particularly important with diesel vehicles.
• Oil leaks under the engine and around the gearbox – they could mean trouble. Axle hub oil leaks are given away by oil splashed on the inside of the wheel rims. Oil seepage around the front axle constant velocity joints (the shiny round thing on each front wheel hub) is normal, but the oil should not drip.
• Bounce and rock the vehicle on all four corners. The bounce should stop quickly. If it does not, the shock absorbers may be worn. Worn suspension bushes will cause clunks and knocks.
• Look for rust. Beware of a newly painted chassis – it may mean hidden rust.
• Open and close all of the doors, the bonnet and the tailgate and wind all of the windows up and down and test the lights and indicators.
• Look for damage to the chassis frame. If there is no visual damage underneath the vehicle, it is an indication that the vehicle may never have been off-road, If the chassis is too clean, beware, fresh black paint could be hiding damage.
• Open the bonnet. The engine should be clean and show signs that it has been well maintained.
• Find the engine and chassis numbers and compare these with the registration held by the owner. Make sure that these numbers have not been tampered with in any way. If you suspect that this may have occurred, walk away.
Here is a guide to what to look for when test driving a used 4×4:
• Start the engine. It should idle smoothly between 700 and 900 rpm. Some diesels running on high-sulphur fuel idle noisily.
• Warm up the engine. Have someone stand at the rear of the vehicle. Quickly push down the accelerator as far as it will go and then release it. There should not be excessive smoke from the exhaust. The engine should accelerate quickly and smoothly.
• Black smoke? Diesels that smoke heavily under acceleration mean an over-rich fuel mixture. This causes turbocharger damage if left for more than a few hundred kilometers. Test the exhaust gas temperatures to determine any turbo damage. Extended temperatures over 750°C likely mean trouble and an expensive repair.
• Blue smoke means oil in the combustion chambers and is likely caused by worn rings and valve guides. Repairs are expensive.
• Listen to the exhaust for escaping exhaust gas from anywhere but the tail pipe. Do this by putting your shoe over the end on the tailpipe. When the engine decelerates it should not smoke. If it does, it may mean worn valve guides.
• Listen to the engine – does it clatter or are there any knocking sounds? Sounds like these can indicate worn bearings, cam chains, rockers, etc. If the engine ticks, it could mean a simple problem of valve clearances that require adjustment or worn hydraulic lifters. It is advisable to have an expert take a look and have a listen.
• Check the air filter – an excessively dirty one will mean a poorly maintained vehicle.
• Driving a 4×4 is different to driving a normal vehicle. Because of the complex transmission and the heavy clutch and transmission backlash, smooth gear changes may be a little difficult to handle at first on some models.
• Test the brakes. Drive at about 50 kph and when it is safe, push on the brake pedal until the vehicle comes to a halt. There should be no tendency to veer from straight-ahead. The brake pedal should not sink all the way to the floor. If it does, there could be fluid seepage inside the brake master cylinder or wheel cylinder which would require a brake system overhaul.
• After driving for a few minutes, check the water temperature gauge. If it is equipped with an oil pressure gauge, check that also. Low oil pressure could mean worn engine bearings.
• Take the vehicle onto the motorway and run it up to a reasonable speed. There should be no undue vibration. Vibration could mean anything from an unbalanced wheel to an unbalanced prop-shaft which could have caused gearbox bearing and oil seal failure.
• Test all gear ratios. Accelerate and decelerate sharply in all gears. Doing this may cause it to jump out of gear, a common problem with well used 4×4 transfer gearboxes, especially Land Rovers.
• Testing a 4×4 off-road is not easy. It is not fair to the owner to go crashing through axle deep mud to see if the vehicle can cope – especially if you are an inexperienced driver. The best way to do this is to look closely at the vehicle specifications and compare them with other vehicles. Ask other owners of the same type of vehicle for their comments. Do this and you will have a good idea of what you are buying in terms of performance.
• Army surplus vehicles have normally been abused and will need a great deal of rebuilding work to get them into a reliable condition. For a few masochists, rebuilding a military truck is worth all the effort.