Category Archives: Vauxhall/opel

How to Fit a Timing Belt on a Vauxhall Vectra

A full timing belt replacement guide for a Vauxhall Vectra 1.8 VVTI model

The Vauxhall Vectra has been a popular car on our roads ever since it was first launched in 1995. The recommended timing belt change interval is every 100,000 miles or 10 years and the engine has been identified as an interference type engine so, in the event of the timing belt failing, engine damage may occur.

Getting started

The first thing to be aware of is that it’s important to replace the timing belt when the engine is at an ambient temperature. We also highly recommended replacing the auxiliary belt when the timing belt is replaced. For safety reasons it’s always best practice to disconnect the battery and, on completion of the repair, reconnect the battery and reset the electrical system as required.

The workshop equipment we used for this repair was a two-post ramp, engine support, cam and crankshaft locking tools. With the vehicle on the ramp, detach the wiring loom from the air box assembly, disconnect the electrical multi-plug from the air mass meter, remove the air intake pipe from the air mass meter and the throttle body and then remove the air box assembly (see below).

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Cover the throttle butterfly to prevent any debris entering the throttle and then remove the upper section of the timing belt cover (see below).

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Now raise the vehicle in the air and remove the O/S/F wheel and under tray/splash guard before mounting an engine support (see below).

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If an engine beam is to be used, this can be fitted when you lower the ramp.

Better access

Lower the ramp and remove both parts of the engine mounting – the auxiliary belt tensioner is now accessible. Rotate the tensioner back to its stop and retain with a locking pin before removing the auxiliary belt. Raise the ramp and lock the crankshaft using the locking tool located into the back of the flywheel and remove the crank pulley.

With the pulley removed check the condition of the rubber drive and bonding for cracks and wear and then replace the bottom pulley/torsional vibration damper if required.

Remove the timing belt covers and the auxiliary belt tensioner, refit the bottom pulley bolt and remove the crankshaft locking tool (see below).

belt-clinic-figure-4-300x200

Rotate the engine to align the timing marks on the crankshaft pulley (see below) and the camshaft pulleys and then locate the crank and camshaft locking tools; the camshaft locking tool is a two piece tool. Inset section one into the inlet cam and then slide section two into the exhaust cam (see below); slight rotation of the cam pulleys may be required to locate the tool as the timing belt may have stretched slightly. belt-clinic-figure-5-300x200

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Belt tension

Now insert an Allen key into the tensioner and rotate in a clockwise direction to remove the belt tension. Remove the belt from the tensioner pulley, camshaft pulleys, idler and finally the crankshaft.

Inspect the timing belt area for any oil or coolant leaks that could contaminate the new timing belt and rectify as required. Replace.

“For safety reasons it’s always best practice to disconnect the battery and, on completion of the repair, reconnect the battery and reset the electrical system as required.”

the timing belt tensioner and idler supplied in the timing belt kit, ensuring that the new tensioner is located correctly, and then torque to the manufacturer’s specification. Ensure the timing marks are all still aligned and then install the new timing belt, starting at the crankshaft and, working in an anti-clockwise direction, the idler pulley and camshafts.

Using an Allen key you should then rotate the tensioner in a clockwise direction to its stop, before sliding the timing belt onto the tensioner pulley and releasing the tensioner to tension the belt (see below).

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Check that the timing marks still align on the crank and camshafts and that the new timing belt is located correctly. Then remove the crank and camshaft locking tools, rotate the crankshaft two complete revolutions, align the timing marks and insert the locking tools to ensure the timing is correct and that the belt is located and tensioned correctly.

Refit all components in reverse order and torque the bolts to the manufacturer’s specification; we also replaced the auxiliary drive belt and tensioner as best practice (see below).

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Reconnect the battery and reset the electrical units as required before carrying out a road test to ensure the car is ready for customer collection.

Ignition Coils – Everything you need to know

COMPANY: NGK SPARK PLUGS (UK) ■ STAND NUMBER: C28

Look under the bonnet of a modern vehicle and there is no doubt that the scene appears different to that of one of yester-year. With regards to ignition, distributors and lead sets are now a rarity – replaced with ‘plug top’ coils and ‘rail’ coils.

The ignition coil sector is now a significant part of the business of NGK Spark Plugs (UK). Although we recognise the importance of still catering for the earlier vehicles, many of which utilise the old metal can type ignition coils which incorporate oil to provide insulation and cooling, we also supply coils for the modern vehicle models that are venturing out of the main dealer network for repair.

What causes the demand for ignition coils is the harsh environment in which they work, which in turn creates a greater possibility of failure. As a result, although not strictly service items as such, many technicians view them in that category.

Coil manufacture has to be of a very high standard these days, mainly due to the high temperature fluctuations they’re subjected to. Many are mounted directly on the spark plugs and the severe cooling/heating cycles that prevail are a test for even the best quality item.

It is worth investing in suitable coil removal tools, not only to make removal easier upon servicing, but to ensure that the body or housing is not twisted or distorted – which can cause unseen damage internally.

Strict quality processes
Compromises on coil quality due to choice of materials used or production costs should never be made without recognising that there is inevitably a significantly greater possibility of premature failure.

The ignition coils in the NGK range have been through strict quality processes, from the initial design stage to assembly and testing. The testing carried out prior to launch ensures the items meet or exceed the vehicle manufacturers’ OE items.

The quality processes also encompass the packaging in which the items are shipped. Attention to detail means that items are safe in transit and, to ensure correct fit first time, the NGK ignition coil packaging includes a label with a schematic diagram of the coil contained inside – so selection can be verified easily without removal from the box.

Coil selection can be made using NGK Partfinder found on the www.ngkntk.co.uk website and the current NGK ignition coils application catalogue is available in paper format, which includes enhanced coil images to further aid selection.

The most recent additions to the NGK range, which was launched in 2013, were 22 new coil types covering vehicles including the VW Up, Mini, Vauxhall Adam, Vauxhall Astra J, Vauxhall Mokka, Mazda 6, Renault Clio IV and Dacia Sandero II. Range expansion is on-going, with emphasis revolving around demand. In total, the range now comprises 340 ignition coils, thus offering a part for a high percentage of the UK car parc.

You can talk to the NGK Spark Plugs (UK) technical team and find out more about its ignition coils range by visiting Stand C28 at Donington Park.

How to replace a clutch on a Vauxhall Zafira

The Vauxhall Zafira has been on our roads for many years, and is a firm favourite with families and taxi drivers alike. The result of this popularity means that this model has sold over 370,000 vehicles in the UK and, as the average mileage of these vehicles increases, we are starting to see more and more in the aftermarket.

A clutch replacement on the Zafira is really straightforward and with the guidance of  LuK  the whole process will become even easier. Nothing out of the ordinary is needed to complete the job, the only special tools required are an engine cradle, a transmission jack and a long axle stand. A two-post ramp was used in this example, however a four-post ramp may not provide enough clearance.

Before starting work, if the vehicle has alloy wheels make sure you have the locking wheel nut. Locate and undo the steering column coupling (pictured below) in the driver’s foot well. Open the bonnet, disconnect the battery terminals and remove the battery clamp. Lift out the battery and the plastic surround and undo the bolts securing the metal battery tray. To provide enough space to remove the tray, undo the single screw securing the ECU mounting and move it to one side.

How to replace a clutch on a Vauxhall Zafira

Release the electrical harness attached to the battery tray and lift the tray out. Disconnect the slave cylinder connection at the top of the gearbox (pictured below) and use a blanking plug to prevent leakage.

How to replace a clutch on a Vauxhall Zafira

Release the gear selector cables from the transmission by carefully levering them off the mechanism (pictured below).

How to replace a clutch on a Vauxhall Zafira

Release the cables from the support bracket and remove the accessible upper bell housing bolts. Using the engine cradle, support the engine and gearbox and remove the gearbox mounting (pictured below).

How to replace a clutch on a Vauxhall Zafira

Raise the vehicle and remove the N/S front road wheel and the plastic engine under-tray. Disconnect the reverse light switch and release the clips attaching the front bumper to the sub-frame (pictured below).

How to replace a clutch on a Vauxhall Zafira

Undo the bolt securing the N/S lower suspension arm to the lower ball joint (pictured below) and release it.

How to replace a clutch on a Vauxhall Zafira

Undo the hub nut on the N/S side and release the drive shaft from the hub. Drain the gearbox oil and remove the short driveshaft from the gearbox. Unbolt the front engine mounting and support the weight of the radiator by using a pair of cable ties on the front panel. Unbolt and remove both rear sub-frame support plates and slacken the four large bolts (pictured below) securing the subframe.

How to replace a clutch on a Vauxhall Zafira

Undo the rear gearbox mount and the bolt securing the coolant pipe to the front of the gearbox casing.

Undo and lower the exhaust downpipe for better access and release the power steering harness attached to the sub-frame. Remove the reverse light switch harness attached to the gearbox casing and, with support, lower the sub-frame down enough for the gearbox to be removed. Finally remove all the remaining bell housing bolts and remove the gearbox.

With the clutch removed, check the Dual Mass Flywheel (DMF) for signs of heat stress and evidence of grease loss. The DMF should also be tested for ‘freeplay’ and ‘rock’ between the primary and secondary masses (LuK tool number 400 0080 10 is specifically designed for this purpose on all LuK manufactured DMFs). Full instructions and tolerance data for all LuK DMFs are contained on a CD which comes with this special tool.

Clean the first motion shaft splines and any debris from the bell housing (especially important when a release bearing has failed). Put a small dab of high melting point grease (not a copper-based product) on the first motion shaft splines and make sure the new driven plate slides freely back and forth.

This not only spreads the grease evenly but also makes sure you have the correct kit. Wipe any excess grease off the shaft and driven plate hub. Using a universal alignment tool and checking the driven plate is the correct way round (note “Getriebe Seite” is German for “Gearbox Side”) the clutch can be bolted to the flywheel evenly and sequentially.

Before fitting the gearbox, make sure the locating dowels are in place and not damaged. Refit any that have become dislodged and refit the gearbox. Make sure the gearbox bell housing bolts are secured before lowering the jack. Refitting is the reverse of the removal.

Dual Mass Flywheels – the importance of a full failure check

When a car comes into the workshop with a potential problem, it pays to take time to run through a check-list before making your diagnosis as there are a number of things to consider when you think you have a rattle from a Dual Mass Flywheel (DMF).

Operating outside of the limits

LuK DMFs, as OE equipment, are tested in the vehicles they are used in at the GVW the vehicle is designed for, using the tune the VM has chosen. If the vehicle is operated outside of those limits, beyond its design life or with a chip tune then the DMF will, like most components under those conditions, wear out sooner rather than later.

DMF DIAGNOSIS CHECKLIST

– Is it the DMF that’s rattling? Does the noise go away when you depress the clutch or get worse when driving round corners? If it’s both then it might suggest it’s the gearbox rattling rather than the DMF.

– Starting and stopping the engine creates the most movement in a DMF so if you hear noises under these conditions it might suggest a worn DMF, but not exclusively.

Does the engine stop cleanly or does it jump up and down on the final gasp? A worn DMF will not cause the engine to perform badly, but a poorly running engine will make a DMF rattle and shorten its life because it’s absorbing more vibration than it should.

Likewise an engine that is cranking slowly due to a poor battery or dodgy starter motor won’t produce a nice clean start and the DMF will be working overtime trying to compensate.

Faulty fuel shut-off valves or dribbling injectors will both create an unsmooth cut-off, or worse, an engine deciding to go backwards for the last turn.

So it’s starting and stopping cleanly and it looks like it is running OK, but when you increase the revs slightly you get a small noise in the transition period. Is the engine still smooth when doing this or is it coughing? Maybe it’s the EGR valve that’s doing the rattling?

Is the engine running like it was when it left the factory? Cylinder-to-cylinder imbalance due to compressions or injectors will all contribute to increased vibration going into the DMF.

So it is running OK, it’s starting OK but we still have a rattling DMF (and we are convinced it’s the DMF) but it has relatively low mileage. Ask the following questions:

  • Do we know this customer?
  • How does the customer drive it?
  • How does the customer load it?

Vehicle manufacturers carry out extensive testing of their vehicles (including running around at maximum GVW) to make sure they can release the vehicles to the general masses, yet we still think we can deliver wet concrete in the back of the Transit!

Vehicle specific issues – Vauxhall Vectra

There are some vehicle specific issues that keep cropping up. The Vauxhall Vectra apparently has a control unit in front of the battery that if not clipped in properly with some force will fool even the most experienced of mechanics into believing the DMF is rattling. The swirl valves or their control unit is equally a popular cause of DMF rattling misfire on the same vehicle as well as glow plugs not working, resulting in excessive cranking to start.

When you’ve identified the reason behind the wear…

In reality the thought process behind all the aforementioned items is a few minutes to a professional. After completing the diagnosis and advising the customer of the cost of bringing their car back to how it was when it left the factory we then advise:

  • Replace the DMF with a component that matches the original specifications;
  • Lock the flywheel before undoing the DMF bolts (to prevent engine damage due to worn timing chains);
  • Make sure you rectify any oil leaks before refitting the DMF;
  • Check the reluctor ring for damage and the correct number of teeth;
  • If a vehicle manufacturer specifies a ‘torque’ and ‘angle’ for the DMF bolt it should be replaced;
  • If there is no complaint of noise, always measure the DMF wear on a vehicle that has come in for a clutch change as it may still require changing.

Don’t take chances

There is an increasing trend for garages to allow customers to purchase their own parts and then fitting this component for them. If you’re considering doing this, ask yourself that if the part you fit converts the vehicle away from its original specification, changing the fundamental characteristics of the engine in the process, whether the customer will hold you responsible if they have a gearbox malfunction further down the line. Not a chance you want to be taking!

How to change a clutch on a Vauxhall Vivaro

Launched in 2001, the Vauxhall Vivaro is an excellent example of mutual ventures between vehicle manufacturers; the Renault Traffic and Nissan Primastar are quite similar applications. With over 140,000 Vivaro’s on UK roads today, this handy clutch replacement guide from LuK should prove valuable.

It is possible to find two types of gearbox designs that changed around late-2006 and early-2007 on these applications. In this article, we tackled the later version of the Vivaro with the wiring loom positioned at the top of the gearbox, which hides the top bell housing bolts, so this will have to be removed. In this repair, we used a two-post ramp, two transmission jacks and a suspension arm lever. The first stage of the repair is to remove the top gear box mount nut with the vehicle still at ground level. The remainder of the repair can then proceed from underneath. Raise the vehicle and drain the gearbox oil. Remove the nearside front wheel. Inside the wheel arch, release two bolts holding in place the side shield (Fig 1).

How to change a clutch on a Vauxhall Vivaro

Fig 1

Support the gearbox using a transmission jack. Release the power steering pipe, which is positioned on the side of the gearbox, by removing two bolts from the retaining brackets. Remove the bolt holding the earth cable in position and stow safely (Fig 2).

How to change a clutch on a Vauxhall Vivaro

Fig 2

Release the second power steering pipe positioned at the front of the engine, held by two bolts mounted to the gearbox mount and one bolt at the rear of the engine. Remove three bolts that hold in place the gearbox mount: two on the side and one on the top. Then, release the top mount from its position. Disconnect the ABS sensor connectors and release three nuts connecting the lower suspension arm to the ball joint on the near side. Using the suspension arm lever, separate the parts (Fig 3), and swing the suspension leg to the side whilst holding and releasing the driveshaft from the gearbox.

How to change a clutch on a Vauxhall Vivaro

Fig 3

Repeat this procedure for the off-side, taking care when releasing the driveshaft from the gearbox, as it locates through a support bearing.

Bracket removal

The bracket will need to be removed releasing two bolts (Fig 4).

How to change a clutch on a Vauxhall Vivaro

Fig 4

Swing the suspension leg to the side, and the driveshaft and bearing will slide out of its location. We secured the driveshaft in place by using a pair of locking grips to stop it from returning to its original position through the support bracket (Fig 5).

How to change a clutch on a Vauxhall Vivaro

Fig 5

Remove the gear linkage and bracket as one complete assembly by removing three bolts – two situated on the side and one on the top of the gearbox – and stow. Disconnect the reverse light switch (Fig 6).

How to change a clutch on a Vauxhall Vivaro

Fig 6

Remove the plastic wiring loom carrier by removing two bolts – one at the front and one at the rear of the gearbox – then stow the wiring loom using cable ties (Fig 7).

How to change a clutch on a Vauxhall Vivaro

Fig 7

Remove the top two bell housing nuts and the two starter motor bolts, and then release the two bell housing bolts on the rear of the gearbox. Secure the front section power steering pipe using cable ties to ease the removal of the gearbox. We tried to lower the gearbox without doing this, and the pipe can get caught on the bell housing, so the pipe must be stowed to prevent any damage. Support the gearbox with a second transmission jack and cradle.

Lower gearbox to the floor

Remove the four bottom bell housing bolts and carefully lower the gearbox to the floor. Remove the worn clutch cover, drive plate and release bearing. With the clutch removed, check the flywheel for signs of heat stress. Clean the first motion shaft splines and any debris from the bell housing, which is especially important when a release bearing has failed.

Put a small dab of high-melting point grease – not a copper-based product – on the first motion shaft splines, and make sure the new driven plate slides freely back and forth. This not only spreads the grease evenly, but also makes sure you have the correct kit. Wipe any excess grease off the shaft and driven plate hub.

Using a universal alignment tool and checking the driven plate is the correct way round (note “Getriebe Seite” is German for “Gearbox Side”) the clutch can be bolted to the flywheel evenly and sequentially Before fitting the gearbox, make sure the locating dowels are in place and not damaged. Refit any that have become dislodged and refit the gearbox. Make sure the gearbox bell housing bolts are secured, and the gearbox mount is installed before removing the transmission jacks. Refitting of the parts is the reverse of removal.

What to do if you encounter thermostat failure

A scenario that will sound familiar to most garage technicians is when a customer reports that, when in traffic, the temperature gauge rises into the red danger zone. A failed thermostat is confirmed as the cause. It’s a problem that could lead to severe engine damage and, usually, it’s a straightforward repair job that won’t break the bank.

For drivers of certain VW group applications (fitted with V6 engines) and some Vauxhall/Opel Group models (fitted with 4 cylinder engines) the cost of the repair can be a lot more expensive. That’s because in these engines, the thermostat sits directly behind the Synchronous Belt Drive System (SBDS) or timing belt assembly. It means that in order to fit a replacement thermostat, the drive belt must be removed.

Examples of VW group applications with such a configuration include the Audi A4 2.4 (Petrol), Audi A4 Cabrio 2.4 (Petrol) & 2.5 (Diesel), Audi A6 2.4 (Petrol) and Audi A8 2.8 (Petrol). Vauxhall/Opel models with similar layouts are the Astra 1.6 and 1.4 (Petrol) and the Corsa 1.2 and 1.4 (Petrol).

Overhaul procedure
Gates advises that if the thermostat on any one of these vehicles fails ahead of a scheduled SBDS overhaul, you should consider bringing the overhaul procedure forward. It is not just good engineering practice, it makes sound economic sense.

Most experienced drive system installers accept that a used timing belt must not be refitted. This is because the correct ‘installation tension’ only ever occurs once – at the point of installation on a cold engine. These parameters are set when the engine is on the OE assembly line.

Installation tension is a critical aspect with respect to overall engine performance and it can only be achieved with a new belt. Most installers also accept that it makes little sense to install new belts without fitting new tensioners and it’s also a good opportunity to replace the water pump (where fitted) in order to ensure that a subsequent leak will not compromise the integrity of the new drive.

For this reason Gates introduced its Kit Plus Water Pump range in 2005. It was a move that gave installers – and their customers – peace of mind. Installers can be sure that the correct water pump is always being supplied. Customers are reassured that in the event of a problem, only one warranty inspection is required because the water pump, belt and tensioner is from a single source.

Kit’s the business
The supplier’s latest initiative is a kit designed to resolve the situation that technicians might face when vehicles with a thermostat located behind the SBDS arrive on the garage forecourt.

Available from this month, the range of ten PowerGrip® Kit Plus Water Pump Plus Thermostat kits also include all of the appropriate seals and gaskets. The initiative fits perfectly with the Gates principle that overhaul, as part of a preventive maintenance approach, is a better investment than a series of piecemeal repairs.

As the cost of replacing the thermostat on these models is relatively small in comparison with replacing the timing belt and its associated tensioners, the new kits provide a cost-effective solution.

How to solve a cam sensor fault on a Vauxhall Astra

Andy Horwat, of Engine Tuning & Diagnostics in Swindon, investigates a cam sensor fault on a Vauxhall Astra 1.6, 56 plate.

An interesting case study recently came my way from a local garage. The car in question – a Vauxhall Astra 1.6 on a 56 plate – had been to another garage and was suffering from a cam sensor fault. It was explained to me that the sensor had been changed twice already but the problem still persisted.

There was a lack of power to the engine and the engine management light was on too, so I took the vehicle for a test drive to gather some more information.

The symptoms I discovered included a severe lack of power and hesitation and the garage owner (who was also an ex-Vauxhall mechanic) pointed out that the sensors were ‘aftermarket’ parts which were found to be incorrect.

Scoping the problem

cam sensor faultMy next course of action was to test the vehicle using my trusty PicoScope, and also to carry out some other tests. From this I found that the cam and crank signal appeared with clean lines, however I wasn’t certain at this point that all was as it should be so I carried out a further visual inspection.

It appeared that the cam timing was correct, but after an hour of conducting checks my attention was drawn to the cam sensor itself. I conversed with my friend who was aware of these Eco-Tec engines, which are known to have variables to them. He spoke with the dealer who agreed and a replacement was ordered and fitted. The fault was then cleared and I took it for a test drive.

I noticed that there was an improvement to the performance but the engine was still lacking in power, so the car came back into the workshop for further investigation. The coil spark was as it should be, while the fuel pressure and flow and mass air flow meter was also checked – no issues.

cam sensor faultA fuel pressure check resulted in 50 PSI snap excel, with no drop in numbers there. It is important to carry this test out in that order as a faulty fuel pump may produce the right pressure at idle but, when put under load, there could be an extensive drop in pressure (as much as 10 PSI or more).

Now I needed to reconsider the symptoms: the drivability had improved but it wasn’t a complete fix as only the engine performance had improved. Over the years many Astra’s like this have come into my workshop so I know what to expect in terms of performance.

Testing the injectors

cam sensor faultFor my next test I tried an ‘injector balance test’. The tool I used was an injector actuating tool, which has three settings (10- 30-100 millisecond) and for this test you need to connect the fuel pressure gauge, disconnect the harness for all the injectors and connect the actuating tool.

On this occasion I used the scan tool to prime the pump, although recycling the ignition key will do. The test showed injector #1 dropped in pressure by 10 PSI, which is my benchmark. Injector #2 was 10 PSI, injector #3 showed a drop of 9 PSI and injector # 4 showed a drop of 6 PSI. It was here that I found the cause of the problem.

“A quality scope is a must have tool as it helped to verify cam and crank correlation and that the cam signals were incorrect.”

This test supports the drivability problem, which is due to uneven fuel delivery, as it should be even across all cylinders with the manufacturer stating that a difference of 1.5 pounds is acceptable. In this case injector #4 was definitely faulty while #3 was on its way out. I recommended replacing both #3 and #4 to the customer, who agreed. The injectors were subsequently replaced and the performance of the vehicle was restored.

We then carried out a further test drive to confirm that the repairs made were correct. This is a typical example of an Eco-Tec engine with multiple problems – cam sensor failures are all too common and it is clearly something that caught the previous two garages out. There are at least three variants to this engine or system design and they share similar problems. The original cam sensor had probably failed and a replacement aftermarket part – which was not compatible with the system – only made matters worse.

cam sensor faultIt’s important that the test drive, symptoms, information and a correct procedure are put into place. In my opinion, a scan tool wouldn’t have proved very helpful in this particular case; in fact using trouble codes to ‘diagnose’ the problem is what caused the previous garages to run into trouble in the first place.

For this reason I believe a quality scope (in my case, the Pico 4000) is a must-have tool as it helped to verify cam and crank correlation and that the cam signals weren’t correct. The other key here was the correct information from the supplier.

The injector actuating tool also proved invaluable, as it took me ten minutes to check all four injectors and to conclude my repair.

Can one engine oil be used for all makes of vehicle?

Comma explains why you should beware the ‘one-product-fits-all’ trap.

Comma periodically issues ‘Tech Talk’ training and information bulletins to help workshop technicians stay abreast of the latest developments and applications in lubricants, coolants, brake fluids and maintenance chemicals.

A recent bulletin reflects on how the once common practice of relying on a single barrel of 10W-40 for use on virtually every vehicle service has had to yield to strict ‘selection by application’ disciplines dictated by modern exhaust after-treatment systems based around three-way catalytic converters (CATs) and diesel particulate filters (DPFs). Such systems are highly sensitive to unwanted sulphated ash, phosphorous and sulphur – so called SAPS – in exhaust gases. It’s a problem that was addressed by ACEA when it introduced the ‘C’ category of reduced or low SAPS oils.

A suitable fit?

Headlined ‘There’s more to oil than “C3”, the bulletin cautions against stocking a single product – in this case ACEA C3 low SAPS engine oil – for use on all vehicles. It says that even though an oil is legitimately coded C3, it is a mistake to assume that it will be a suitable fit for every vehicle requiring an ACEA C3 oil.

As Comma points out, VMs now demand something very much more ‘bespoke’, and have their own distinct formulations for the ACEA C3 oils they specify for their engines. It is also the case that ACEA C3 isn’t only used with 5W-30 grades – certain Alfa Romeo and Fiat engines require ACEA C3 as a 5W-40 grade.

To illustrate the point, the bulletin uses spider charts below to show how certain oil specifications of VW, GM and Mercedes Benz differ greatly, one from another, while still conforming to – and in some areas exceeding – the ACEA C3 performance levels. The bulletin draws the conclusion that, by itself “ACEA C3 doesn’t always match VM specification.”

Comma-Engine-Oil-1
ACEA C3 vs VW 504 00/VW 507 00
Comma-Engine-Oil-2
ACEA C3 vs Vauxhall (GM) dexos 2
engine oil
ACEA C3 vs Mercedes-Benz MB 229.51

Trustworthy application data

With VMs’ lubricant recommendations now widely written-in as warranty critical requirements, the safest way to ensure correct selection is to use an up-to-date and trustworthy application tool, such as CommaOil.com. Here, technicians will find complete ranges of Comma engine oils, antifreeze and coolants in which they can have total confidence, covered as they are by the brand’s unique 100% ‘Compatibility Guarantee’ and embracing all European vehicles dating back over 30 years.

Starters & alternators technical bulletins – Various models

1. JAGUAR ALTERNATOR CHARGING PROBLEMS
On Jaguar XJ and XK models (1996-2003) when an alternator problem is diagnosed, some customers have experienced charging problems – even after the fitment of a replacement unit. This is due to the battery being fitted in the boot of the vehicle. Consequently the wiring connections in the boot, passenger foot-well or false bulkhead under the bonnet may have high resistance. These should be checked and cleaned thoroughly. The part number primarily affected is AEK2286.

2. FURTHER WIRING PLUG JAGUAR NOTES
If the replacement alternator is overcharging after fitment, the cause may be due to no signal to the ‘C’ terminal of the connector plug from the ECU.

If there is no signal to the ‘C’ terminal on the alternator from the ECU, the alternator will show an overcharge of approximately 15.7 Volts. Possible causes of this are a broken wire in the loom, connector pins in the plug being damaged or open too far to make a good connection, or there may be an ECU fault. Part numbers affected are: AEK3195, AEK3196 and AEG1066.

3. VAUXHALL VECTRA 2007 ON 1.9 CDTI DIESEL BOSCH ALTERNATOR PULLEY FAILURE (see example images above and below)
Check the clutch pulley on the alternator that has been removed from the vehicle. If the pulley is seized, spinning freely in both directions without the alternator turning, collapsed or is missing, this will indicate a vehicle fault which has caused failure of the alternator. Fitting the new alternator without rectifying the vehicle fault will result in premature failure of the replacement alternator. Check the belt tensioner for correct operation and ensure that the belt has been correctly routed. The part number affected by this very common issue is AEK3125.

4. MERCEDES ALTERNATOR CHARGING FAULT
Check for faulty seat modules on Mercedes applications from 2000 onwards. A flat battery can lead to an incorrect diagnosis and subsequent replacement alternators can be fitted with the flat battery problem persisting. Often the problem is later found to be an electrical drain caused by a faulty seat module. Part numbers affected are: AEC1752 and AEG1142.

Technical help from Autoelectro
Autoelectro’s website ‘catalogue’ section lists specific technical information for many applications. All you have to do is click on the red ‘i’ that accompanies the product specifications.

Why does poor turbo boost occur?

Unfortunately, simply installing a direct replacement may not be the end of the story when a workshop is faced with a problematic turbocharger.

If performance problems in a petrol-engine vehicle persist, even after the replacement has been fitted, the issue may well be due to a malfunctioning recirculation air valve (RAV).

If the RAV is damaged or malfunctioning, the inevitable result is poor engine responsiveness and, to make matters worse, the problem could even lead to the turbocharger failing as a result of it being overloaded.

The RAV is installed either directly on the turbocharger itself or in the pressure side area of the charge air line. Poor engine performance can be caused by factors such as a ruptured membrane on the inside, leaking control lines or corroded plug contacts.

With electronic RAVs, an entry is generally created in the ECU, so checking the fault memory will save workshops a lot of time and unnecessary labour.

What does a RAV do?
The task of the RAV is to take a proactive measure against turbo lag by preventing a backlog of charge air, which can accumulate as a result of gearshifts and causes the deceleration of the rotating assembly.

If the driver suddenly eases off the accelerator pedal at high turbocharger speed, it will cause the throttle valve to close and high dynamic pressure to be generated on the compressor side, which cannot escape. This counter pressure drastically slows down the impeller and leads to high mechanical loads on the turbocharger and the closed throttle valve. Once the gear change is completed and the throttle valve reopens, the turbocharger has to be brought up to speed again, which is why there is a delay.

RAVs minimise the delay following these load changes – commonly known as turbo lag – by releasing the accumulated charge air between the compressor side and the closed throttle valve via a bypass. Once it has passed through the compressor, it is guided back into the intake section ahead of the turbocharger.

This loss of pressure on the compressor side prevents a deceleration of the impeller and when the throttle valve reopens, the RAV closes and the boost pressure increases immediately. Therefore a noticeable drop in performance should always lead technicians to check the RAV before replacing the turbocharger.

Turbo range
Through its joint venture with Bosch, MAHLE Aftermarket is now able to supply the UK aftermarket with an extensive range of OE quality turbochargers for petrol engines developing 45-220 kW and diesel engines rated between 35-165kW.

Latest additions to the MAHLE Original range are part numbers 011TC17498000 for four cylinder 92kW engines fitted to Vauxhall Vectra, Saab 9-3 and various Volvo models, 082TC14411000 for four cylinder 135kW engines used in BMW 3 Series and X5 models and 222TC15242000 for three cylinder engines fitted to the Smart range.