Recalls: HSV VU Maloo
Overview
Manufacturers, or importers, issue recalls for defects or faults which have the potential to cause injury. Generally, manufacturers will inform the original buyers if their vehicle is subject to a recall and of the steps required to remedy the defect or fault. Please note that the recalls below (if any) are for Australian-delivered vehicles only. Furthermore, the number of recalls should not be taken as an indication of a model’s reliability or its safety more generally.
Recalls: HSV VU Maloo
- In July 2001, a recall was issued for certain HSV VU Maloo vehicles that were manufactured prior to March 2001. In these vehicles, an interruption of the electrical current to the fuel pump relay, fuel pump connectors and low-beam headlight relay could cause the fuel pump and low-beam lights to fail. To fix, the old relays (part number 92047112) were replaced with new relays (part number 92107897) (PRA 2001/4844).
Problems and faults: HSV VU Maloo
Overview
This section identifies potential problems, causes and fixes based on the experiences of owners and repairers, online sources and technical service bulletins. This information is provided solely for reference purposes and AustralianCar.Reviews recommends that only properly qualified persons carry out repairs or modifications. Furthermore, the number of items below should not be taken as an indicator of a model’s reliability or the frequency with which they may occur.
To report a problem or fault to the AustralianCar.Reviews team, please use the Contact Us form. Note that AustralianCar.Reviews does not offer advice on automotive problems or disputes; such enquiries will not receive a reply. For vehicles purchased from dealers after 1 January 2011, please see our Australian Consumer Law fact sheet.
HSV VU Maloo: LS1 V8 engine
Overview
With the exception of the early 5.7-litre LS1 V8 engines, General Motors’ LS V8 engines are regarded as being generally reliable. However, they may experience the problems described below.
Hydraulic lifter failure
For GM’s LS V8 engines, the hydraulic lifters may fail due to:
- A failed plunger within the lifter itself. When the plunger fails, it cannot maintain oil pressure and remains in a collapsed state – the lifter therefore cannot take up valve lash such that a tapping noise is heard that increases in volume and frequency with engine speed;
- The spring mechanism jamming – this is more common in older engines;
- Inadequate lubrication of the lifter roller wheel surface causing friction on the lobe (this generally results in a squeaking noise);
- Softened valve springs which also require replacement; or,
- Worn lifter buckets.
A failed hydraulic lifter can bend the pushrods which can then fall out of the space between the rocker arm and the top of the lifter. Once a pushrod falls out of that space, it may cause broken rocker arms, broken valves, cracked heads, a damaged cam or total engine failure.
It is recommended that the lifters be replaced every 100,000 kilometres, though failure of the hydraulic lifters is more common in engines with high-lift camshafts because higher spring pressure are required to prevent valve float, putting extra pressure on the lifter. Replacing the lifters requires that the cylinder heads be removed such that new head gaskets and head bolts are required.
Hydraulic lifter noise
From cold start-up, the hydraulic lifters may make a tapping noise. The most common cause of hydraulic lifter noise is particles in the engine oil becoming jammed between the lifter plunger and the lifter body, causing the plunger to become stuck down. The clearances between the plunger and body of a hydraulic lifter can be as little as 3 microns (0.003 mm) such that any particle larger than this in the oil can jam the lifter plunger in its body.
Lifter noise may also be caused by aeration of engine oil in the lifter’s pressure chamber since this increases valve closing velocity. Aeration of engine oil may be caused by:
- air in the higher pressure chamber of the lifter affecting valvetrain lash;
- air that is ingested into the lifter during a cold start due to a suction side leak at the oil pump or oil pump pick-up tube O-ring; or,
- low oil levels and high engine speeds.
Once air gets into the high pressure chamber, it will be slowly expelled through the narrow clearance of the plunger and body.
Rocker bearing failure
The rocker bearings – which sit on top of the valve train and transfer energy from the pushrod to the valve – can develop a sideways slop which can damage the valve tops, the rocker or valve springs. Furthermore, the rocker bearings can split such that the needle bearings fall out and end up in the oil pan.
Trunion bearing upgrade kits can be installed in the factory rockers which reduce sideways movement and provide a better range of vertical movement. Alternatively, after-market roller rockers can be installed which have better geometry than the standard rockers and control the valve more precisely via the centre of the valve tip.
Valve spring failure
The LS engine has ‘beehive’, single valve-type valve springs (as opposed to a dual valve spring which has a smaller spring inside the primary spring) and, in rare cases, the valve spring may break at its top where the coils are tightly wound. If a single valve-type valve spring breaks, it is common for the valve to be dropped, causing significant engine damage; sometimes, however, the valve may be held up by the valve locks when the spring is breaks. Symptoms of broken valve spring include:
- Engine vibrations;
- Loss of power beyond 4000 rpm;
- Misfire under load; and,
- Constant misfire.
If the vehicle is driven with a broken valve spring, a valve may come into contact with the piston, causing the valve to be bent. Furthermore, if the valve head breaks off, the engine will seize. To fix a failed valve spring, the cylinder heads need to be removed so that a new valve, head gasket and head bolts can be fitted.
For durability, it is recommended that high rpm are avoided when the engine is cold.
LS1 V8 engine: other problems and faults
- The engine cover may rattle as it comes into contact with the coil/bracket assembly; the support brackets and mounting nuts were subsequently revised. For manual models built prior to VIN #L867194, the engine cover may also rattle against a twisted hydraulic clutch hose; in mid-2002, a revised clutch hose with quick-connect fittings was introduced.
- Excessive engine vibration may be due to the powertrain control module (PCM) calibration (later revised with improved idle speed control), a stressed exhaust system or a bent catalytic converter bracket (spacers can be added to keep the bracket straight when bolted in place).
- Squealing noises from 1500-1900rpm may be due to the power steering pump pulley being misaligned with the crank and alternator pulleys.
- For automatic models, a chirping or squealing noise from the serpentine belt under hard acceleration and when shifting from first to second gear may require a revised belt tensioner with increased damping to be fitted (released in early 2002).
- A rough idle, high-pitched hissing noise and ‘check engine’ light illuminating may be due to the PCV (positive crank case ventilation) pipe deteriorating; a revised PCV pipe was subsequently released.
Transmissions
- At the first use of the clutch pedal after a cold start, there may be a squealing noise which recurs when the clutch is disengaged – this may be due to incorrect fitment, damage or a lack of lubrication of the spigot bush.
- The gearshift knob may vibrate in third or fourth gear at wide open throttle openings from 2500-4000rpm due to excessive clearance between the shifter knob and lever; from March 2002, gearshift knobs were glued on. Furthermore, the gearshift lever may rattle due to excessive clearances in the remote shifter linkages; a revised remote shifter was introduced in late 2003.
- It may be difficult to engage gears and the clutch pedal may feel soft and/or have a low disengagement point due to a chemical reaction between the clutch fluid and clutch slave cylinder housing (which produces a gas in the hydraulic system); a revised clutch slave cylinder was released in late 2003.
- It may not be possible to select gears if the remote shifter mechanism front pivot ball dislodges from the nylon retainer – this may occur if excessive force is used for gear changes. A metal reinforcing plate was subsequently introduced to prevent this from occurring.
- Excessive road or gear noise from the transmission shifter area may be due to a split inner boot or a loose retainer plate. A revised gearshift boot and retainer plate was introduced in early 2002.
Problems and faults: HSV VU Maloo
- Excessive rear inside tyre wear may require a rear camber kit to correct wheel angles. However, worn control arm bushes can also affect wheel alignment and tyre rear.
- Noises from the front suspension during low speed manoeuvres may be due to the rubber bushes on the front sway bar links having compressed or split.
- Grinding noises from the front wheels when cornering may be due to the ingress of small stones or dirt into the front strut upper support bearing; a foam dust seal was subsequently released to reduce this problem.
- After long drives or high operating temperatures, there may be a clunking noise from the front of the vehicle that is also felt through the steering wheel when turning – this may be caused by excessive movement of the inner tie-rod end of the steering rack. A revised tie-rod was introduced in early 2001.
- Excessive free play in the steering wheel may be due to the upper bearing of the steering column failing; a revised bearing was introduced in 2001.
- V8 models with automatic transmissions may have a droning noise from the rear suspension at around 110km/h due to vibrations from the rear suspension cross member; a revised cross member with vibration dampers was introduced in August 2002.
