My car has a check engine light

Thursday October 01 2020

Paul Kaganzi

Hello Paul, I recently imported a Toyota Mark X 2012. A few days ago, the engine sound changed to a loud sound, it reduced power as I can hardly overtake and there is an orange light on the dashboard, which my friend says means check engine. What could be the problem? Kenneth.

Hello Kenneth,

Find a mechanic who can inspect your exhaust pipes to confirm that the catalytic convertors have not been stolen. Catalytic convertors are important components of your exhaust system located under the car and connected to the exhaust pipes. They are designed to remove or reduce harmful compounds in the exhaust such as carbon monoxide or nitrogen oxides. 

When removed from your car, the engine management system will notice their reduced efficiency and automatically detune the engine. 

This will cause the reduced engine performance and loud noise from the empty exhaust pipe catalytic convertor cartridge. 


Catalytic convertors are built with some rare minerals such as palladium and rhodium, which some crafty dealers are ready to die for. Theft of the catalytic convertors happens in less than a minute if the thief has the right tools. Targeted areas or spots popular for CAT thefts include isolated parking spots, parking lots and ungazetted car wash bays. 
Also, avoid leaving your car unattended or at insecure parking lots.

Hello Paul, I own a VW Tuareg which I bought from UK. One of the front coil springs is broken and I am wondering why it broke. With a mileage of 120,000, isn’t it too early for the coil spring to break. Also, can I drive like this for about three months before I get a replacement? Nsubuga.

Hello Nsubuga,

Your front coil springs could be breaking because of worn out front shock absorbers. Your VW Tuareg has a high mileage of 120,000 miles (200,000kms). I would not be surprised if your shock absorbers are worn out or damaged. Often, bad shock absorbers can lead to failure of the springs. 

Shocks help to reduce the compression of springs and prolong their life span. When your shock absorbers are worn out, the springs can snap during extreme off road driving. Another likely additional factor is corrosion damage. 

Being an ex UK car, there is a likelihood that the springs may have also been weakened by winter salt corrosion damage, which is a common problem.

I would not encourage you to drive around with a broken coil spring. The second spring is likely to fail soon. If both shocks and coil springs are damaged, they can compromise vehicle control and safety, especially when you are driving at high speeds on the highway.

Hello Paul, I have recently bought a 2006 Pajero Mitshubishi DBA-V93W. However, it has a loud humming noise. Is this normal or is something wrong? Nebert 

Hello Nebert,

Your car is a four wheel drive station wagon.

 The common cause of a deafening humming sound with 4WD vehicles is a worn out or dry differential unit. The differential unit is a set of spider gears and bearings encased in a housing and designed to transmit the engine’s torque to the wheels via shafts. 

When the differential unit operates while dry due to differential oil leaks or with damaged gears due to delayed service, it makes a howl or whine during acceleration. In extreme situations, it may judder while you turn corners.

The noise you hear is a sign of impending gear seizure or catastrophic failure. Consider an immediate road test and inspection by a mechanic to determine whether the differential unit is the source of this noise and the course of remedial action. 

Worn out or damaged wheel hub bearings and use of offroad tyres with aggressive tread patterns can also cause this humming noise as you drive faster on the highway.

Hello Paul, my Toyota Fielder 1500cc 4WD produces noise from the rear axle or diff. What could be the problem? Sam

Hello Sam,

The noise from the rear axle of your 4WD Toyota Corolla Fielder may be from a damaged differential carrier or worn out transmission coupling radial bearings.

 An experienced mechanic will be able to discern from the noise to determine which of the two components (differential carrier and transmission coupling radial bearings) are damaged. 

Together with a mechanic, you can road test and listen out for the noises. 
Here are a few common rear axle noises and possible causes. 
A whirring noise while reducing speed is most likely bad or loose pinion bearings. 

A howl or whine while accelerating is commonly caused by worn out pinion gears. Rumbling while driving through corners is usually caused by worn out carrier bearings. Banging and clanking during high speed driving suggests faulty spider gears.