Cos I'm bored because my G40 doesn't drive at the moment I've been bashing the forums and already I'm sick of..'buying a G, what to look out for'. So in an attempt to save us all some time I've typed up everything i can think of at 3am. if we can all add any bits I've missed over the next few days and then if hayes can maybe chop it and pin it somewhere we can direct people to it's link? Here's what I've wrote...feel free to add...
Common Faults/Details on the 91-94 VW polo G40
This document is a rough guide to specific and well known issues associated with the VW Polo G40. It should provide a brief insight into problem areas and what to look for when buying/considering a G40. It does not particularly consider the many modifications and customisations available and only considers the fundamental issues recognised to the G40. Many issues are common sense checks and issues that any buyer inspecting a car should be aware of. This document therefore aims to only highlight issues specific to the G40.
Engine
The hydraulic tappets should be smooth and the engine should rev freely. The blue temperature sender is often a common failing item that should be replaced with a VAG item every few years to ensure the ECU gets a good readout. It uses the data it receives from the temperature to adjust the fuelling. An incorrect reading can cause many running problems. Check the condition of the oil and look for evidence of the dipstick popping free of its clip, oil marks on the bonnet directly above this area which would indicate high crank case pressure from a blocked breather on the back of the block forcing the dipstick out. The G40’s breather is pressed into the back of the block, unlike other models which are bolted on. Leaking sumps, rocker gaskets are also common leaking areas. Usual checking of head gasket failure should be carried out as with any car but evidence of oil leaking on the driver side front corner of the cylinder head can indicate the head gasket is beginning to blow. All 10 head bolts should be replaced with every head gasket change and are specific to the G40 being slightly longer. Expect around £5 per bolt from VAG. The G40 is often known to suffer excessive temperature rises especially after an enthusiastic drive. Thermostat housings can often leak at the mounting to the cylinder head. This can either be the housing itself cracking or the rubber O ring.
The G40’s gearbox should not present many problems as such but the clutch cable can often cause problems either being stiff or rough and eventually leading to snapping. Engine electrics if left mainly untouched should present very little problems. Alternators can over time fail, as with any car, ignition coil too but this is by no means a specific problem of the G40.
Supercharger:
Often thought of as a liability or the Achilles heel of the G40 the G charger is actually surprisingly robust in standard form. Many have been known to last well into 100k miles. It is recommended however that regular servicing take place in order to ensure the maximum boost potential of the G charger and to prolong the overall life of the component. Blowing seals can reduce boost dramatically and damaged bearings can cause catastrophic failure to the charger itself. Preventative maintenance is the key. Increasing the boost with a smaller pulley is an easy, effective and popular modification but reduces the time between recommended rebuilds significantly. It is recommended as a rule of thumb that a charger on a standard pulley is overhauled every 40k miles and one on a smaller/toothed pulley is overhauled around 20k. It goes without saying that there are many other factors that influence the performance/longevity of the charger including, how the car has been driven, letting the engine warm thoroughly before using full boost and quality/age of oil used in the engine.
Loose, torn or split boost pipes will affect boost levels and a wrongly adjusted throttle cable will also affect boost if the throttle butterfly does not fully close when the accelerator pedal if fully compressed. Removing a boost pipe and inspecting inside should reveal slight oil misting. Puddles of oil may suggest blowing/damaged oil seals within the G charger.
Brakes:
Known to be a little ‘spongy’ the ventilated disks and rear drums should provide sufficient braking power for a slightly modified G40. Correctly adjusted rear drums can mean the difference between a nice responsive feel and a very ineffective pedal. Normal brake maintenance will apply to front discs and pads and rear drums. The G40 also has a rear brake compensator to the rear nearside which can suffer leakages. Updating the rubber brake hoses for braided metals ones is a popular upgrade.
Suspension:
Again a little primitive but nonetheless can still provide a comfortable and enjoyable drive. Front top mounts are often known to fail. G40 specific rose jointed steering arms and bottom arms can be the cause of knocking and banging when excessive wear occurs. Replacement parts for these are becoming scarce and in some cases obsolete from VAG dealers. Anti roll bar bushes can be updated and many suspension packages are available from various companies.
Body:
The shell is no different to any of the mk2f 86c polos built between 91-94. If undamaged and if they have not been in a collision and been subject to damage repair the shell should remain reasonably healthy. Areas that particular attention should be paid to are sill areas, particularly to the rear drivers’ side. Often when a new fuel tank has been installed the obstructing sill can get twisted and pulled in an attempt to remove the old tank neck. This can lead to cracking of factory sealant and rust creeps in to this vulnerable area. Sills to the front underneath the foot wells are ‘drainage points’ often mistaken for jacking points these are often pushed inwards. Front chassis legs have been known to crack on the nearside to threar of the leg and this should be checked regularly, especially if the power of the car has been increased dramatically, increasing the stresses on the chassis. A bump to this nearside front should be checked thoroughly to ensure no damage has occurred to this vulnerable area. Other areas prone to damage are bottoms of doors from water collection inside the doors, particularly if water drainage holes have become blocked, rear panels under rear lights if the seam sealer has become broken or cracked allowing moisture in, bottom corners of the windscreen, rear boot behind number plate plinth and inside door areas of the rear quarters where the seat belts have swung outward chipping the paint. The G40 has black plastic trim around its arches and sills, held in place with black rivets. These should be secured tight and can hide a multitude of sins if water has had a chance to access. A uneven front panel strip below the headlights may be a goood indication of accident damage as well as badly fitting bumpers with uneven gaps.
Interior:
The drivers’ seat is adjustable by height and should rise quickly and easily. Side bolsters especially on the drivers side can wear through and sponge can collapse. The 3 speed heater should work on all three settings. Only working on setting 3 is often the resistor found on the top of the heater matrix to the back of the engine bay. Seats should be secured by a small 10mm nut to the front and runners to the rear and should slide easily along them. Seat cables often snap within the seats making them difficult to lift to gain passenger access to the back. Replacements are available very cheap but the seat back rest will need to be partly dismantled to replace them. Interior light failure is often defective, seized or corroded push switches found on the inside of the door hinge area.
Daniel Mokhtari (Supercharged Spaniel) 02/08/09
