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.
- Engine Oil
- Automatic Transmission Oil
- Brake Fluid
- Cooling Systems
- Disc Rotors
- Timing Belt/Cambelt
- Steering
- Suspension
- Intermittent Failures
- Dashboard Warning Lights
1. Engine Oil
1.1 What does the engine oil do?
- Engine oil lubricates, cleans, cools and protects the engine and all moving
parts to eliminate excessive wear.
1.2 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.
1.3 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.
1.4 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!
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2. Automatic Transmission Oil
- 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.
2.1 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.
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3. Brake Fluid
3.1 What is brake fluid?
- Brake fluid is the hydraulic oil used throughout your vehicle to transfer
pressure to the brakes.
3.2 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.
3.3 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.
3.4 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.
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4. Cooling Systems
4.1 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.
4.2 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.
4.3 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.
4.4 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.
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5. Disc Rotors
5.1 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.
Hint
- 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.
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6. Timing Belts
6.1 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.
6.2 Do all engines have a timing belt?
- No, some engines use a timing chain.
6.3 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.
6.4 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).
6.5 Would there be any warning before the belt breaks?
- Not usually. It is what we call an “instantaneous unforeseen failure”.
6.6 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 travelled.
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.
6.7 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.
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7. Steering
7.1 Steering shakey or pulls
- The steering system on every car is very important and requires regular
maintenance to keep it at an optimum standard. The steering rack on all motor
vehicles is easily knocked out of alignment by all the speed humps and potholes
in the road. When the wheel alignment becomes out of tolerance the tyres will
wear unevenly on either edge of the side walls.
- Noticeable signs of wheel imbalance to look out for are:
- Steering wheel is off-set when the vehicle is travelling in a straight line.
- The vehicle may drift/pull to the left or right.
- The front tyres will wear bald or show signs of uneven wear on either edge.
- If any of these faults are present on your vehicle we strongly recommend you
have your wheel alignment checked and adjusted if necessary, as soon as
possible.
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8. Suspension
- On the suspension system there are many moving parts, the main component of
which is rubber that can dry out over a period of time and can crack and perish.
In the worst situation the rubber components can split. You may be able to
recognise when a component has become defective, some of the effects could be;
- When pulling away from a standstill a knocking noise may occur from the front of
the vehicle.
- When travelling along uneven surfaces, i.e. speed humps or bumpy roads, once
again a knocking noise may be heard from either end of the vehicle and the ride
in the vehicle may be an uncomfortable one.
- On a straight road, i.e. a motorway, if one side at the front of the vehicle
there is a defective component, the vehicle will drift or pull to the defective
side.
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9. Intermittent Failures
- “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.”
“Can't you just plug that tool in to the car that tells you
what’s wrong with it?”
“How much will it cost and how long will you need my car?”
“What does it sound like to you?”
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.
9.1 Can we plug that tool into the car?
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.
9.2 How much will it cost and how long will you need my car?
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.
9.3 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.
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10. Dashboard Warning Lights
(Check Engine, ABS, TRC, VSC, ALB etc.)
10.1 Why do we have them and why won’t they 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”.
10.2 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)
10.3 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.
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