Wheel balancing will sort you out
Posted Thursday, January 24 2013 at 02:00
Qn:I have two cases on my Toyota Corona (Kibina).The signal for over drive (O/D) keeps blinking as I drive. The O/D when applied (pressed) when I am overtaking works well. What could be the cause of the blinking? Has it any effect on the overall performance of the car operation system?
A blinking over drive light (O/D) when you are driving means there are faults in you automatic gearbox electrical control system. These faults are recorded in the memory of the gear box control unit and can be accessed by use of a manual diagnostic procedure or the use of a computerised diagnostic tool. If a malfunction occurs with the speed sensors for number 1 or 2 or gearbox solenoids number 1,2,3 or 4, the over drive light light will blink to warn the driver. In the absence of a diagnostic computer, a repair technician can bridge terminals TE1 and E1 in the diagnostic socket then count the number of flashes which represent a fault code. You can download the detailed interpretation of the O/D light flashes from a Toyota diagnostic fault code chart.
2. Sport rims. What can one do when after balancing the tyres but the car still rolls as if the wheels are in an oval shape, especially when driving below 50km per hour on new very flat surface tarmac roads?
I had never experienced this before with non-sport rims on other cars in the past, but this has happened to me on two cars with sport rims. Should I change rims?
What is the solution?
Ans:You need to balance your alloy wheels (rims) on a computerised wheel balancing machine. Testing one of the wheels might confirm whether the others are also damaged and whether you should bother to spend money balancing all of them.
In which case you ought to replace those wheels. Alloy wheels are easier to damage if you drive them hard over pot holes and humps. You should inspect the condition of your tyre tread, unevenly worn out tyres can also cause the sensation of driving on an oval shaped wheel.
Qn:I have enjoyed reading your head to head for the Mercedes W124 and the BMW E34. I own two Mercedes W124s an estate and a sedan which I use to traverse the countryside. I have a sagging roof lining, can it be repaired?
Ans: Your Mercedes W124 roof lining is made of a fabric material lined with a thin layer of foam, like the one which makes foam mattresses. This foam lining is a millimetre or so thick, when you park your car outside, on a sunny day for so many years, the foam disintegrates into small flaky debris. As a result your roof lining sags. Any attempts to glue the old roof lining back are futile as it will not hold or simply drip through the fabric.
A permanent solution is to replace the old lining material with a new one, which is affordable and readily available in Kampala.
Qn:I drive a 2001 Toyota Vista with a D4 engine. It has got 70,000 kms on the clock. The car does not accelerate normally. Can you advise how we can solve the problem?
Ans: Your Toyota with a D4 engine (short for direct injection four stroke) has an improved petrol delivery system. Petrol is directly injected into each cylinder through slit like nozzles. This process improves combustion, cold starts, fuel economy and engine output.
The catch is you have to be very diligent to a strict maintenance regime as this sort of engine is sensitive to clean oil, fuel and air supply. Assuming that you have replaced your air filter and spark plugs, I advise that you renew your fuel filter.
It is located in your fuel tank and often ignored by average service technicians because it requires attention to detail during the replacement procedure. The fuel filters are available at major Toyota parts dealers in town.
Qn:My Toyota Corolla AE100 has starting difficulty. Whenever we try to start, the battery runs out. My mechanic has replaced the battery but the new one also runs down. We replaced the fuel pump but there is no change. The car consumes a lot of engine oil. Kayemba, Mbarara
Ans: You need a good car electrician to inspect your car’s electrical system for short circuits or consumers that may be draining your battery when you switch off the ignition and to confirm that your alternator charging capacity is normal.
However, the fact that your car consumes more than normal amount of engine oil suggests that your engine may have a low compression problem.
For an engine to run, it must have enough compression to raise the temperature of the air fuel mixture high enough so that a spark can easily start an efficient combustion process.
If there is not enough compression, the engine will fail to start. An engine low compression situation can be caused by damaged piston rings, cylinders or the cylinder head gasket. The more than normal oil loss in your engine points in that direction. Ask your mechanic to use a compression gauge to confirm this diagnosis.