Correct set of keys

The need for the correct set of keys and immobilizer remote cannot be over emphasized when one is buying a used vehicle.

A lot of used car dealers in developing countries do not sell the vehicles with the correct set of keys.

Usually, the buyer is given only one ignition key and is convinced to buy or make a second spare key later.

Any car buyer should be wary of this option unless he or she is quite sure the ignition keys can be obtained easily and cheaply.

It is not uncommon to spend hundreds of thousands of naira in obtaining and programming the keys of most vehicles built after year 2000.

There are also many cases where a lot of unnecessary diagnostics and repair are made because of faults related with the micro chip embedded in programmable ignition keys.

The availability of a second ignition key already programmed into the vehicles immobilizer and ECU solves this problem easily.

If you must buy a vehicle with only one ignition key, please ensure you negotiate well to cover for the cost of the acquiring the extra keys.

Even when the dealer provides an extra ignition key, ensure you insist the dealer or seller provide you with the original vehicle documents or the four , five , seven , eight or twelve digit immobilizer code used for the key programming.

Most vehicles have this code stamped on the original vehicle document or on a tag supplied with the original keys.

Finally, it is very possible that the reason the vehicle has only one key is because it was stolen from the original owner.

Owners do not drive their vehicles with the spare ignition keys in their pockets so be wary of all single-key deals.

All cars should be bought with at least two sets of keys (insist on them and collect all documents and negotiate for a discount if the keys are not complete or walk away and find another vehicle) .

VIN number check for factory recalls

VIN is an acronym for Vehicle Identification Number. This is a seventeen digit number that is used to identify the vehicle.

This number is usually found etched on top of the dashboard near the driver or passenger side windshield or on the driver side door pillar tag.

The VIN usually contains the following information:

The country the vehicle was manufactured

Model and Series of the vehicle

Engine and Vehicle type

Accessories fitted

Model year

Particular assembly plant vehicle was builtThe sequential production number for the specific vehicle.

The specific chassis and engine coding format may vary slightly for each vehicle manufacturer however, each manufacturer includes these information in the VIN.

Due to design, manufacturing or component related problems, new vehicles sometimes have design or mechanical faults unknowingly built into them.

Sometimes the fault affects only one model in the vehicle line of the manufacturer, at other times there are faults in specific batches of vehicles manufactured at specific times of the year while there are times when the faults affect the components (for example) fitted to different models of vehicles manufactured over several months.

This is not an indictment on the vehicle manufacturers, rather these faults arise due to the extreme complexity of the modern automobile, the sophisticated manufacturing processes and the last element in the periodic table, the human element.

Manufacturers use the VIN number to identify vehicles that have defects and then issue a notice for repairs on all vehicles whose VIN number is within the range identified.

Every manufacturer has its own fair share of defects. Certain Honda and Ford vehicle models have been recalled for transmission related problems. Rover had to recall some FreeLander models for overheating problems, BMW issued a recall notice on the X5 models related to torque converter bearing failure, so has Jaguar, Toyota, Cadillac, Volvo, VW issued several recalls on different areas of the vehicle.

A used or even new car buyer should periodically browse the internet for any recalls issued on the particular vehicle of interest and confirm that any manufacturer defects indicated in the recall notice has been rectified if possible.

Using the VIN to get information on any recalled issued for a vehicle also helps the technician repairing the vehicle distinguish between problems caused by normal faults that could occur and factory related faults that will not easily be diagnosed and hence can save you a lot of money and time.

Overheating

Many used car buyers have to spend extra money repairing their vehicles after just purchasing them. The common problem is that of engine overheating. To repair an overheated engine, the top cylinder gasket has to be replaced amongst other things.

A lot of vehicle owners are not observant and rarely look at the coolant temperature gauge in the instrument panel when they are driving. This makes it impossible for them to spot early cooling system failures.

Before buying a used vehicle, ensure you drive it for up to forty to sixty minutes with the air conditioner switched on preferable on a hot day.

Pay the dealer for this test drive if necessary because it is much cheaper than dealing with the problem . Test the vehicle in slow moving traffic for this period to ensure that the engine does not have an over heating problems.

Some vehicle dealers leave just about one gallon of fuel in the tank thereby limiting the time the vehicle can be tested. It is advisable to buy more fuel and test the vehicle till it is ascertained that the vehicle does not have an overheating problem.

Do not allow the thermostat of the vehicle to be removed when the vehicle is being repaired, have it replaced with a new one.

Do not allow the coolant fan control system to wired directly to the ignition switch (The coolant fan should not turn when the ignition switch is turned on) rather insist the technician replace the related sensor.

Replacing the top cylinder gasket for modern vehicles with multiple computer controlled valves is a task for the most competent specialist.

The correct data on valve timing and the torque settings on all the critical bots holding the cylinder head is very important if the repair is to be done successfully.

On vehicles equipped with TOY ( Torque to Yield ) cylinder head bolts, these bolts must be replaced if the cylinder head is dismantled.

Some vehicle might even require several component alignment procedures that can only be done with manufacturer specific diagnostic tools (VW might require Throttle Body alignment, some GM vehicles will require *CASE learn procedures while other vehicles might require accurate sensor alignment). *CASE - - Crankshaft Angle Sensor Error

The idea of your technician just replacing the cylinder head gasket in any vehicle built after year 2000 without having the correct technical information on the replacement procedure is not advisable.

Watch out for Interference Engines

There are basically two kinds of engines produced by manufacturers. The interference and the non interference engines.

In an interference engine, if the timing chain or belt fails, it can lead to a total destruction of the cylinder head or a bending and or breaking of all the valves in the engine as well as cracking the cylinder head while in a non interference engine, failure of the timing belt does not damage the engine though the engine will not start.

Vehicles that use a chain link to drive the valves do not constitute a problem because the chain drive gets very noisy many thousand kilometers of use before failing completely, hence there is some form of early warning produced by the noisy chain drive.

However for vehicles with belt drives ( not fan belt but timing belt that is inside the engine) , the belts can fail suddenly .

Most timing belts are designed to last for about sixty thousand miles or about one hundred thousand kilometers and most used cars exported to developing countries are exported at about this same mileage.

If you are lucky to obtain the maintenance record of the vehicle, you can check to confirm whether the belt replacement has been carried out or when the belt replacement is due. Do not wait for the timing belt to fail because by then it might be too late.

When replacing this belt , please look for the most qualified professional , buy the original manufacturer recommended timing belt and be prepared to pay for quality service.

Trying to avoid any of these always leads to very expensive and unpleasant driving experience.

As a rule of thumb, most multi-valve engines with two or four camshafts are interference engines and as such manufacturers are reverting to using chain drives instead of belt drives.

Belt drives were preferred because it made the engine whisper quiet , in some of the vehicles with belt drive you have to come listen very attentively to know the engine is on and running.

Check Engine Light

The Malfunction Indicator Light (MIL) or the Check Engine Light (CEL) informs the driver of the vehicle that some engine or emission related fault has occurred.

This does not necessarily make the vehicle un-drivable, however, it pays perform a diagnostic scan with the manufacturer recommended tool in order to ascertain the nature of the problem.

Running an engine diagnostic scan does not replace the need for a competent technician who can interpret the results obtained from the scan.

Although many technicians can locate the diagnostic port on the vehicle and connect a scanner or diagnostic equipment, the results of the scan are not so easy to interpret correctly.

Incorrect interpretation of the data normally leads to the expensive replacement of components that are not defective

As an example, a failing timing belt will usually trigger a diagnostic code related to the camshaft and crankshaft sensor.

An inexperienced technician is likely to replace these two very expensive sensors after which the problem remains.

The technician can subsequently replace the timing belt. This operation can take so much time, cost a lot of money and open up more possibilities for mistakes.

Always perform a diagnostic scan when the check Engine light comes on and ensure you get full information on the errors indicated by the check engine light before buying a used vehicle.

This will help you negotiate for a better price or to go for another vehicle.

Remember that once the vehicles battery is removed, the vehicles computer memory erases and the light will go off.

However, after about thirty minutes of driving at moderate to high speed, the Check Engine Light will come on again.