Frequently Asked Questions
Below are some of the more common questions that our clients ask, and their answers.
More questions and answers will be added as time goes on, so please check here first if you want to know the answer to something. If you have suggestions about FAQs we should add to this, please let us know here.
What does the engine oil do?
- Engine oil lubricates, cleans, cools and protects the engine and all moving parts to eliminate excessive wear.
Why do we change the engine oil?
- Engine oil is manufactured with friction modifiers and cleaning agents necessary for the modern engines of today.
- These additives are sacrificial and therefore after a period of time are no longer evident, leaving the oil contaminated with harmful acids and sludge which causes wear.
- Lack of, or prolonged oil changes is a major factor in premature engine wear and oil seal failures.
How often should the oil be changed?
- For normal use (mostly highway driving) - 10,000 kms or 6 monthly, whichever occurs first.
- For severe use (short trips, stop and go traffic, high speed etc) - 5,000 kms or 6 monthly, whichever occurs first.
- High performance engines, diesels and turbo-charged engines - 5,000 kms or 6 monthly, whichever occurs first.
What grade of oil should I use?
- This depends on what vehicle you drive. When we change your engine oil we use the grade most suited to your engine, using manufacturers' guidelines.
We personally recommend our clients change their oil every six months or at the very least once a year. After all, it's far cheaper to change your oil than to change your engine!
- Automatic Transmission Fluid is rarely changed for preventative maintenance, yet it is often the cause of premature transmission failure.
- If you consider the cost of changing the fluid and filter in your transmission periodically, it is negligible compared to the cost of a transmission overhaul.
- It is proven that changing the transmission filter and fluid every 40,000 to 50,000 kms can significantly prolong the life of your transmission.
How do we change the fluid and filter?
- Depending on the vehicle make and model, some transmissions have external filters exactly the same as an engine and some have a filter inside the gearbox which requires the pan to be removed and then replaced.
- We change the transmission oil using a fluid exchange machine which pushes the old oil out and adds the new fluid at the same time.
What is brake fluid?
- Brake fluid is the hydraulic oil used throughout your vehicle to transfer pressure to the brakes.
Why change the brake fluid?
- Brake fluid is a hydroscopic fluid, meaning that it attracts moisture. Moisture is created from the heating/cooling effects of normal brake use, also humidity from the atmosphere.
- This moisture causes rusting and pitting of internal parts, which leads to unnecessary replacement costs. Under severe braking excess, moisture can cause the fluid to boil, leading to brake failure.
When is it necessary to change the brake fluid?
- We test the moisture content using a hydrometer. Once the fluid has an excess of 3% moisture, we will recommend replacing it. This is checked annually by us and normally requires changing every 2 years.
Will I notice any difference in my brakes?
- If the system is well maintained and the fluid has been replaced on a regular basis, in most cases the brakes will feel the same.
- If the brake fluid is overdue for replacement, we usually find that the brake pedal is firmer, with less travel and less pedal pressure is required to stop the vehicle.
Why do vehicles have coolant/antifreeze in the engine?
- The antifreeze/coolant prevents the cooling system freezing in cold climates.
- It helps raise the temperature at which the coolant in the engine would normally boil.
- It prevents corrosion of internal components in the cooling system.
What happens if there is no coolant/antifreeze in the system?
- Over a period of time, rust and corrosion will appear in the cooling system. Long term, this will reduce the life of cooling system components such as the radiator, water pump and coolant hoses.
- In extreme cases, failure of cylinder head gaskets and other engine damage can occur.
How do I know if my coolant/antifreeze needs renewing?
- We use chemically treated test strips (similar to ones used in spa/swimming pools) that change colour depending on the condition of the coolant.
- We also use a refractometer to measure the antifreeze level.
How often should the coolant/antifreeze be changed?
- Most manufacturers recommend a two-year interval. Some vehicles now have a long life coolant, which can last for four years.
- When there is visible rust in the coolant system.
- When the cooling system test is low on antifreeze or anticorrosive.
How do you change the fluid?
- We use a Coolant Flushing Machine, which gets rid of all the old fluid and replaces it with the correct quantity of new fluid.
Why do we machine the disc rotors when replacing disc pads?
- Modern vehicles today have better braking systems than vehicles of yesterday, but to achieve this the frictions applied are far greater and generate a lot more heat, causing disc rotor warping and bending. This is normally felt as a brake shudder or brake pedal pulsing. Excess noise can also be generated due to glazing of the disc rotors again caused by heat.
- By machining the disc rotor surfaces at brake pad replacement time, you are ensuring that your brakes are back to "as new" condition and therefore more efficient and safer.
- All rotors are measured before machining. If they are under minimum thickness we recommend replacement.
- Don't wash your wheels just after driving your car as the cold water hitting the hot brake parts causes disc rotor distortion, again leading to shudders and pulsing.
What is a timing belt?
- A timing belt is a component used by engine manufacturers to keep the engine’s valves and pistons in correct time.
Do all engines have a timing belt?
- No, some engines use a timing chain.
How can I tell if my vehicle’s engine has a timing belt?
- Ask us. Usually we will know but if we are unsure we can then consult our technical data.
Why should the belt be replaced before it fails?
- When the belt breaks your engine will stop immediately, sometimes with catastrophic results (valves contacting with the pistons).
Would there be any warning before the belt breaks?
- Not usually. It is what we call an “instantaneous unforeseen failure”.
So how can I tell when the belt should be replaced on my engine?
- All engine manufacturers have recommended replacement intervals based on time (age) and kilometers traveled.
- The rough guide of no more than five years or 100,000 kilometers – whichever occurs first. This does vary and manufacturer’s specifications should always be adhered to.
How much does it cost to replace the timing belt?
- Prices vary on different makes and models due to engine design and complexity.
- Other components that run with the timing belt such as the water-pump, idle pulleys and belt tensioners may have to be replaced at the same time, but this would make it safer and more cost effective in the long term.
• “My car misfires sometimes.”
• “The engine won’t start at times.”
• “The engine surges, but only first thing in the morning.”
• “It runs fine until it is hot.”
• “It only misfires going up a really steep hill.”
As a repairer, these are just some of the statements/questions that we hear from our clientele on a daily basis.
Intermittent failures are frustrating both for you, the vehicle owner and ourselves, the vehicle repairer.
They are also a fact of life in the modern vehicle, with multiple electronic micro processors, sensors, actuators, kilometers of wiring and CAN data bus systems all talking to each other at the same time.
Yes we can, however it is not always that simple. After getting all the information from you about what is happening to your vehicle, we would indeed plug in our scan tool and confirm whether any stored faults have been recorded by the ECU. In some cases, the code will lead us directly to the problem or the start of the problem and we can carry out a straightforward repair.
That is where you are pleased to have your car back (fast!) and we look like car magicians – an ideal scenario. But, what about the nasty problem? That only happens approximately once a week and doesn’t leave a fault code to be scanned. What then? That is where the other two questions arise.
Unfortunately, unlike our first case, we will not be able to give you an estimate of time and cost. With an intermittent problem that the vehicle’s on-board diagnostics cannot capture, we have to capture and diagnose when the problem is occurring. So, if the problem occurs only once a day or once a week; that is the only time we have a chance to trace the fault.
We will use a Labscope with recording capabilities which we can replay and we will use all our skills we have gained through experience and constant training. However, we cannot monitor all the components and wiring at once.
Depending on what the problem “sounds” like, we will embark on a logical diagnosing process until we trace the fault.
As your repairer, we will make you aware of this situation before we commence on what could be a long and costly experience.
We find the best approach is to agree on a starting price and for us to report to you on our findings as we go.
As for the time it takes, once again there is unfortunately no easy answer – it will take until we have traced the fault.
(Check Engine, ABS, TRC, VSC, ALB etc.)
Why do we have them and why
go out sometimes?
These warning lights are operated by micro processors called an E.C.U. (Electronic Control Unit).
The ECUs not only operate the systems but they constantly monitor the various sensors and actuators, checking their input and output signals. If one of these signals is outside the normal operating perimeters, the ECU will switch on the warning and light and set what is known as a “Fault Code”.
As a repairer, how do you know what fault code has been set?
To assist us in diagnosing the fault in your vehicle we use a scanner which we plug into the diagnostic plug on your vehicle and check the fault codes stored. Some of these systems can have in excess of 100 different codes that can be set depending on the fault in your vehicle.
Once we have the code, it gives us a starting place to diagnose the fault in whichever system we are looking at – engine, brakes, transmission etc.
The usual procedure after we have repaired the fault is to erase the
code, road test the vehicle and recheck the ECU for codes.
(We will record the code for future reference)
What should I do if a light on my dashboard comes on and remains on?
Please contact us so we can tell you if it is something that should be actioned immediately and inform you whether it is safe to drive your vehicle.
Any warning light appearing on your dashboard, whether it remains on or comes on intermittently should never be ignored. Under most circumstances it will leave a fault code which we can scan to start our diagnosis.