Virtual Mechanic

PURPOSE
The air flow meter is a component to allow the velocity of air through it and at the same time it measures the air passing either by a hot wire or a flap connected to a potentiometer.  This value is sent to the computer indicating the quantity of fuel required.  If the air flow meter is a hot wire type it also has a self cleaning process to keep the wire clean from the value interference.

THINGS TO LOOK FOR
The main thing to affect the air flow meter is the large ducting connected to the unit. Also any vacuum leaks will affect the air flow meter value.  A potentiometer may wear its contacts causing a possible flat spot or non start.  Its enemy is a backfire as this will twist the flap making it impossible to move freely.  A quick perusal will determine if the flap is twisted after a backfire thus requiring replacement.  The hot wire type may break, the wiring causing a non start.  The hot wire also has a self clean program.

IS IT EXPENSIVE TO REPAIR?
Either air flow meters are expensive to replace costing around $600.00 depending on the make.

TEMPORARY REPAIR AND LONG TERM REPLACEMENT
Most common types of air flow meters are now reconditioned costing around $300.00.  Make sure you keep your receipt in the Virtual Mechanic folder, as air flow meters do play up from time to time.

 
This article is found in the Virtual mechanic CD Rom
You can download it for the price of a latte, but you will learn not to buy a lemon
By Darren Gow-Brown, Melbourne Australia ©2009

PURPOSE
The EGR valve is design to recirculate exhaust gases but only after idle and before full throttle.  The EGR valve operates mainly on cruising. 

THINGS TO LOOK FOR
Over time the EGR valve may be responsible for poor idle.  EGR valves are sometimes difficult to pinpoint as being the perpetrator of a poor idle.  A quick inspection to see if the needle is moving or if any exhaust gases are coming from the valve may be determined by an electronic fuel injection specialist.
 
IS IT EXPENSIVE TO REPAIR?
The EGR valve can be expensive.  You can try the wreckers but nine times out of ten a new EGR valve is the best way to go as the second hand EGR valve would usually have been on the engine from when the vehicle was new.

TEMPORARY REPAIR AND LONG TERM REPLACEMENT
Most EGR valves are not serviceable.  The EGR valve is specifically designed to eliminate or reduce exhaust gasses entering the atmosphere.  Tampering with an EGR valve may incur fines.

This article is found in the Virtual mechanic CD Rom
You can download it for the price of a latte, but you will learn not to buy a lemon
By Darren Gow-Brown, Melbourne Australia ©2009

PURPOSE
The clutch slave cylinder is designed to plush the clutch lever in order to engage or disengage the clutch lever or fork.  The clutch slave cylinder has a bleeding nipple fitted  and bleeds the clutch hydraulic system.

THINGS TO LOOK FOR
The clutch slave cylinder is a component under pressure while it is in use making it possible to leak.  If there are any drops, or dampness is found around the clutch slave cylinder, it needs to be attended to ASAP.  The most common sign is a clutch pedal going to the floor and also there is difficulty in selecting gears. If you have to force a gear selector into gear this is the time to stop as the selector mechanism is a fragile component that will not tolerate the mechanisms being forced.

IS IT EXPENSIVE TO REPAIR?
The clutch slave cylinder is repairable but not if the bore is scored then it needs to be replaced, costing between $50.00-150.00.

TEMPORARY REPAIR AND LONG TERM REPLACEMENT
It is possible to repair the clutch slave cylinder especially if it is made of cast iron but check the bore.  If the bore is scored it may be better replaced.  The clutch slave cylinder will need to be bled after being installed.

This article is found in the Virtual mechanic CD Rom
You can download it for the price of a latte, but you will learn not to buy a lemon
By Darren Gow-Brown, Melbourne Australia ©2009

PURPOSE
The carburettor is a very important multi function component as it mixes air and fuel together and it allows the engine to idle, to rev and to maintain desired speeds and overtake on full throttle.  At the same time its purpose is to mix air and fuel at the correct ratio.  The carburettor is only designed to operate with clean fuel and must be mounted securely in the manifold. 

THINGS TO LOOK FOR
The carburettor is capable of leaking fuel.  Signs of dampness or of red colour are indications of this.  Any fuel leak or smell must be attended to A.S.A.P.  A carburettor is also capable of blocking up the cruising, idle or full throttle circuits.  All these circuits are linked to a fine orifice or emulsion tube.  A flat spot or an automatic choke staying on for too long, indicates a problem circuit but the most dangerous indicator is a sticky throttle as this may cause an accident.

IS IT EXPENSIVE TO REPAIR?
Carburettors are costly, ranging from $85.00 for a single barrel to $350.00 for a four barrel.  Fuel over the years may gum up the operation and this is time to have the carburettor serviced.

TEMPORARY REPAIR AND LONG TERM REPLACEMENT
A blocked carburettor may go away or it may stay and require mechanical attention.  One option is sucking the problem out with a rag but be very careful as anything with fuel is dangerous and you can risk a backfire in your face or risk damage to your skin.
This article is found in the Virtual mechanic CD Rom
You can download it for the price of a latte, but you will learn not to buy a lemon
By Darren Gow-Brown, Melbourne Australia ©2009

THE EFFECT
Non start..

THINGS TO LOOK FOR
Remove the distributor cap and have a look at the rotor button when cranking.  If it doesn’t turn, this is either the distributor drive stripped or the cam shaft gear stripped.

COST
Somewhere between $65.00-$300.00.

This article is found in the Virtual mechanic CD Rom
You can download it for the price of a latte, but you will learn not to buy a lemon
By Darren Gow-Brown, Melbourne Australia ©2009

THE EFFECT
A tappet noise can be an irritating noise but it is better than a quiet tappet.  Tappet noise may be the result of hydraulic tappets requiring replacement.  It also may be the effect of a low oil level or the result of the tappets requiring adjusting.

THINGS TO LOOK FOR
Check the oil.  If it’s been a long time since the oil has been changed, eg. 10,000kms, change the oil.   Consult your local spare parts dealer and tell them you’ve got noisy tappets.  They might be able to suggest a thicker viscosity oil.  Also check to see if your tappets are hydraulic or adjustable.  If they are adjustable then it might be okay to get these tappets adjusted.

COST
Getting tappets adjusted costs around $35.00-$45.00.  Getting hydraulic lifters replaced costs around $180.00-$250.00.

 
This article is found in the Virtual mechanic CD Rom
You can download it for the price of a latte, but you will learn not to buy a lemon
By Darren Gow-Brown, Melbourne Australia ©2009

THE EFFECT
The whole neighborhood gets to hear it!  It’s a high pitched metallic noise that when cranking the pinion gear from the starter motor is trying to turn the ring gear that has no teeth left. 

THINGS TO LOOK FOR
Basically what you will find is that with every second crank, every fifth, fifteenth or hundredth crank, you will hear this noise..  If the noises become more common, eg. every second or third or tenth crank, it’s time to get the ring gear fixed and also the starter motor pinion will have to be examined to see if it’s worn.  It may be causing the ring gear to wear.

COST
Cost of a ring gear or fly wheel and the starter motor pinion may cost around $600.00 for the complete job.  A temporary repair is, with a set of gloves,  to try to move the harmonic balancer.  That way you are moving the location of those sets of teeth and of the ring gear, and the car might start if you are stranded in a remote location.

This article is found in the Virtual mechanic CD Rom
You can download it for the price of a latte, but you will learn not to buy a lemon
By Darren Gow-Brown, Melbourne Australia ©2009

THE EFFECT
A loose timing belt will rub up against the plastic housing surrounding the belt.  It also can cause a distributor drive to chatter at idle.  A loose fan belt may slip causing the timing to go out which can give poor performance or  cause a potential misfire.

THINGS TO LOOK FOR
If you feel you have a suspect timing belt you may have to remove some of the housing to get to it to feel the belt  to see if it is loose.  Otherwise take the belt to your local mechanic to rectify.

COST
The cost to adjust a loose timing belt is around $30.00 but remember, this timing belt lasts somewhere between 60,000-80,000Kms.  If it is around about that time, it might be a good idea to get the timing belt replaced as a timing belt replaced before it snaps is by far the cheapest repair or service on any fan belt.
This article is found in the Virtual mechanic CD Rom
You can download it for the price of a latte, but you will learn not to buy a lemon
By Darren Gow-Brown, Melbourne Australia ©2009

THE EFFECT
A loose fan belt is a fan belt screaming out for help.  Also a loose fan belt may perish or deteriorate rapidly depending on whether it’s a polyrib belt or a
‘V’ belt.  A loose fan belt will also affect the charge rate and the cooling system if the water pump pulley is connected to that fan belt.  Any fan belt that is loose will affect what it’s driving.

THINGS TO LOOK FOR
Check the belts for tension.  If they feel loose, tighten them up.

COST
Nothing; if you do it yourself!  When you check the fan belt make sure there is no oil around the fan belt and it isn’t cracked.  An oily or cracked fan belt is a fan belt that is no longer useable.  With an oily fan belt you will have to get the oil leak fixed ASAP as it will affect the belt until it is repaired.  Also the oil leaks onto the road and that can become a safety hazard.  Fan belts cost between $5.00-$65.00 depending on the make and model.  Some fan belts are difficult to changeover, so it might be a good idea to get your mechanic to fit a new fan belt.  When checking one belt, check all of them, as they all seem to go at the same time.
This article is found in the Virtual mechanic CD Rom
You can download it for the price of a latte, but you will learn not to buy a lemon
By Darren Gow-Brown, Melbourne Australia ©2009

THE EFFECT
The car will overheat mainly when it’s idling.

THINGS TO LOOK FOR
A thermo fan should switch on periodically when idling.  If it does not, make sure the connection to the thermostatic fan switch is okay. A fan fuse might also have gone.  Check all the fuses. Find the thermo fan relay, wiggle the relay or swap that relay with an air conditioning relay, provided that the amperage on the relays are all the same.

COST
Depending on why it’s not switching on.  If it’s the fuse it will only cost 50 cents but if it’s the thermo fan switch it could cost around $90.00.  The thermo fan itself could cost $150.00.  The wiring could cost $30.00 to correct.  The thermo fan not switching on may be bypassed or bridged at the relay or at the connection, just to get you home.

This article is found in the Virtual mechanic CD Rom
You can download it for the price of a latte, but you will learn not to buy a lemon
By Darren Gow-Brown, Melbourne Australia ©2009