Your shock absorbers may need to be replaced sooner than later

Qn:Everyone who sits in my car says my shock absorbers are worn out, however, I feel the car is quite comfortable. How can I tell that my shocks are “dying” or already dead? Sarah

Ans. When shock absorbers wear out they can cause a rattle or a thumping noise because they are coming into contact with the body of the vehicle. Worn out shock absorbers will cause your car to ‘bounce’ unevenly when you drive over humps or railway lines. Some worn out shock absorbers leak oil and this is visible when you carry out an inspection. A qualified mechanic can dismantle them and confirm their condition. Generally shock absorbers should be inspected every forty thousand kilometres.

Qn:How can I tell when my tyres need replacing? Is there an “at home” test I can do or do I need to take my car to a tyre dealer? I have heard that you look at the treads but mine appear fine. Jennifer

Ans. Tyres need to be replaced when they wear beyond the legal or safe limit. The extent of tyre wear or condition of tyres on your car affects its performance during braking and the need for traction when driving on a slippery terrain. It is a good practice to check the condition of your tyres once a month or before and after a long journey. There are a couple of ways you can tell whether your tyres are due to replace, without the help of a tyre dealer, but your common sense.

You can look at the tyres for excessive wear. Start by visually inspecting the tyre tread patterns and confirm that they are above the tread wear indicators. These are small ‘bars’ or ‘bridges’ located between the tyre treads, across the tyres. Tread wear indicators are designed to warn you the driver or authorities that it is time to change a tyre when they flush with the tyre treads. Your tyres may have treads that look good to you, but as long as they flush or are below the tread wear indicator bars, they are due to replace.

Check the tyre side walls for deeply worn out areas, bulges or bubbles and small slits or holes. All of these are signs of how soon your tyres should be replaced. A tread depth indicator is another way you can tell the condition of your tyres at home. This little pen size tyre inspection tool can be bought from a car tool shop or supermarket like Game or Shoprite. This tool will show whether your treads are worn beyond the safe limit of 1/16 of an inch or 1.6 millimetres. Simply place it between the treads and it will quickly give you an answer.

Qn: I have a Toyota Rav4 with 108,000 kms on it. I took it to get an oil change. After changing the oil, I got right on the highway at about 60 mph. I was able to drive for about three kilometres before it started to shake. Right away, I knew something was not right. The low oil pressure light came on and the car just stopped on its own. I checked the oil dip stick and it was dry. I then called the place and informed them about what just happened, the mechanic that came to the scene and poured oil into the car. Then, they started it. What kind of damage was done and what should I expect in the long run. Solomon

Ans. One needs to observe your engine performance after this incident to know how severe the damage was, if any at all. Monitor the following closely: if the car requires frequent oil top ups, if there is an unusual engine sound like a clutter or rattle and the colour of exhaust fumes if they increase. The fact that your mechanic put oil in the engine and you drove away suggests that there was no major damage of internal engine moving parts like the crank shaft, bearings and seals or piston rings. There is some important information that your mechanic should have provided such as why the oil level was low, just after an oil change and how much oil he needed to top up before getting the correct level on your engine oil dipstick. Assuming he had to fill it up with four litres of oil from dry, then I would think you either drove away from the service pit with no engine oil or the oil drain plug was loose and it all poured out.

Qn: My Nissan X-trail (2004 model) with a petrol engine has 134,000 kms. When started cold or when it has been driven a couple of hours ago, it idles rough on start up, then goes away shortly after, even when you rev it a little. I had the throttle body cleaned and the injectors serviced and new spark plugs put in. Even with the old spark plugs, it is doing the same. Before the service, it idled rough, and now with the service done, it still idles rough on start up. Also I am topping up the coolant in the reservoir on a weekly basis. What could this all mean? Thank you for your help. Jonah Sentongo

Ans. Make sure that your car engine has no vacuum leak along the engine air intake. You need to have a computer diagnostic test to rule out a faulty air flow sensor, camshaft position sensor or coolant temperature sensor. Those sensors regulate the engine control unit’s delivery of fuel and spark. The mass air flow sensor and coolant temperature sensor provide information about the temperature outside the car and in the engine. This information is used by the computer to determine how much fuel is needed for cold start enrichment or normal running.

The camshaft position sensor provides information which helps the computer to harmonise fuel injection timing with engine ignition timing. If any of these sensors fail, the engine computer will operate in a limp mode by delivering fuel and spark erratically to enable you access the repair workshop. You ought to replace your “in tank” fuel filter, as your mileage it is overdue for replacement. Refilling the engine coolant reservoir means you have a leakage. Check all coolant hoses, the water pump seals, coolant reservoir and radiator for leaks. Confirm that this car does not over heat, if it does, you will need to investigate condition of the cooling fans, thermostat and water pump.

Qn: I own a 3,000 cc petrol Toyota Harrier 2002. I have been enjoying it until recently when its fuel consumption shot up. My mechanic tells me it is showing a check the engine light on the dashboard. I have changed spark plugs, air cleaner and engine oil but the problem persists. Can you suggest a solution? Irene Namukasa.

Ans. You need to replace your engine oxygen sensors. A computer diagnosis can confirm that. These are located along the upper part of the exhaust line. Your car has a V shaped engine with six cylinders. Each engine bank has an exhaust line, hence the two oxygen sensors. If your car’s mileage is above 100,000 km you ought to replace the timing belt and roller bearing as well as the in tank fuel filter. All parts should be available with a genuine Toyota parts dealer in town.

Qn: I drive a Toyota Corona (Kibina) 1994 with a 2,000 cc petrol engine. It has 127,956 km. This car loses power when I start, what could be the problem? Geoffrey Simbwa

Ans. Your car is overdue for the Toyota service B check. You need to replace your fuel filter, located in the engine bay. Check its condition or replace spark plugs and air filter as they can cause engine loss of power when you start.
At your car’s mileage it is important that you replace the engine timing belt. Toyota advises you to replace it at or before 100,000 km. In the event that it snaps, your car engine will be extensively damaged.

Qn: I recently I bought a 2003 Toyota Camry but after four months, my car speedometre became erratic. When it works, car transmission shifts well; when it doesn’t, transmission will not shift out of the first gear. What can I check?
Nelson Sempereza

Ans. Nelson, on your Toyota Camry, the common denominator between the speedometre and your transmission is the Anti locking brake system (ABS) and its wheel speed sensors. The odometre on your instrument clustre receives the speed signal from this ABS system unlike the old odometer which is connected to the transmission by a mechanical odometer cable.

Your automatic gearbox shifts in response to engine speed and wheel speed information from the engine and ABS unit respectively. The ABS control unit receives wheel speed information via the wheel speed sensors. In the event that one wheel speed sensor fails, your odometre and auto transmission will not work. the intermittent failure suggests that there is a short circuit on one of the sensor cables. A computor diagnosis will point out which one.

Qn: I am having an issue with brakes of my Toyota Corolla. The pedal needs to be pressed all the way to the floor to engage the brakes.There are no lights lit up on the dash. The pads and rotors are new, lines have been bled and we just replaced the master cylinder, and the car is still doing the same thing. What else could it be? Thanks! Odur Nathan

Ans. You need to check the wheel brake cylinders to confirm that the pistons have free play and the rubber seals are not worn or leaking. Also confirm that the cylinders have no corrosion which affects the seals.