Vauxhall / Opel Astra (H: 2004-2009)

M20 & M32 gearbox bearings

Some Vauxhall Astra D models are fitted with the infamous M32 gearbox. A typical problem with this 6-speed transmission is bearing wear. In particular, the 6th gear bearing.

When this bearing starts wearing out, the gearbox becomes noisy when driving in 6th and 5th gear. If not fixed, this problem leads to total gearbox failure (a hole in the gearbox).

The M20 gearbox is almost identical, so it suffers from the same problems.

The M20 & M32 gearboxes are used in so many vehicles and bearing failure is so common in high-mileage vehicles, that I’ve dedicated a full page to the M20 & M32 gearboxes.

Follow the link above to learn more about the symptoms of bearing failure, the solution to the problem and how much it costs to fix a dying M32 gearbox.

The M32 and the M20 gearboxes are used in the following Vauxhall Astra H models:

• 1.6 Turbo (Z16LET) – M32

• 2.0 Turbo (Z20LEL, Z20LER, Z20LEH) – M32

• 1.3 CDTi (Z13DTH) – M20

• 1.7 CDTi (Z17DTH, Z17DTJ, Z17DTR) – only the 6-speed cars have the M32, the 5-speed cars have the less problematic F23 gearbox

• 1.9 CDTi (Z19DT, Z19DTJ, Z19DTH) – M32

IDS+ shock absorbers (CDC)

Some Vauxhall cars are equipped with Continuous Damping Control (CDC), which a type of active suspension. As the name implies, it actively changes the damping stiffness of the shock absorbers, depending on the road conditions.

It can improve handling in certain situations, like braking or cornering, and soften the suspension when stiff damping is not needed. From first-hand experience, I can say it works quite well.

The CDC is an optional extra in the Astra H and it’s a part of the “Interactive Driving System Plus” package. You can recognize a car with the CDC by the IDS+ icon appearing on the dashboard when you turn the ignition on.

The icon should disappear a couple seconds after you turn the engine on. If it stays on, there is a problem and the system isn’t working (the suspension gets set to hard damping).

The system is cleverly designed, but at some point, the shock absorbers will need to be replaced just like in any car.

When the time comes to replace the shock absorbers in your Vauxhall Astra H equipped with IDS+, you will be looking at around £350 for a new CDC shock absorber. If you want to replace all four, that will be £1500-2000 if you include the cost of fitting.

Luckily, there are other options. You can have the shock absorbers reconditioned for half the price of a new one. There are companies that specialize in these kinds of jobs. Another option is to bin the CDC shock absorbers and fit standard shocks for a fraction of the price.

Once the original shocks are removed, the CDC must be disabled in the car’s computer to get rid of the IDS+ light on the dashboard.

Easytronic transmission failure

The Easytronic is an automated manual transmission. While I’m not a fan of this technology, the Easytronic is one of the better automated gearboxes used in mass-produced cars.

The gears and the clutch are operated by three electric motors. There are no hydraulics (apart from the master & slave clutch cylinders), which makes this transmission simpler and more reliable than Fiat’s Dualogic/Selespeed automated gearboxes.

The Easytronic is pretty much the same thing as the Durashift EST transmission used in the Ford Fiesta Mk5. Both gearboxes have nearly identical clutch actuators and gear selector motors (just in a slightly different arrangement to accommodate different manual gearboxes).

While the Easytronic is a light-weight and efficient gearbox, do not expect it to be as smooth as a conventional automatic transmission because it doesn’t have a torque converter to cushion the gear changes. It is, after all, a manual gearbox with actuators attached to it.

When buying and test driving a car with the Easytronic gearbox, look out for the symptoms of malfunction:

• Flashing “N”  or “F” letter appearing on the dashboard instead of the gear number

• Car refusing to start (blown brake light bulbs may cause this too)

• Clunking noises when changing gears

• Excessively hard gear changes

• A sensation that the clutch is slipping (worn clutch)

• Juddering when taking off from a standstill

• Car dropping out of gear while driving

• Car refusing to engage gear when trying to take off from a standstill

While the Easytronic is reasonably reliable, below are the three things that you should know before buying a used Astra H with this transmission.

I. If the transmission fails, you will have a problem (unless you can fix stuff yourself).

The Easytronic uses brushed electric motors to operate the gearbox.

The brushes in these motors will eventually wear out, and the transmission will stop working – it’s one of the most common reasons for Easytronic failures. Replacing the brushes is fairly easy and inexpensive if you can do it yourself, or when you find someone experienced with these transmissions. They aren’t common though, so it may not be that easy.

If you go to the dealership instead, they will most likely offer to replace one of the actuators for something like £1000. If they don’t replace the right component the first time, there goes another £1000.

Trying to fix a faulty Easytronic box is often expensive, which is the norm for automated and dual-clutch transmissions. This is unless you can diagnose problems yourself or know a garage that’s experienced with these transmissions and can fix the actual problem (as opposed to replacing half of the transmission). They are actually fairly simple once you understand how they work.

II. The Easytronic has a standard dry clutch, which is a consumable item, just like in any manual transmission.

The Easytronic cannot creep like a traditional automatic transmission because it doesn’t have a torque converter. Taking off and crawling at very low speeds is achieved by partial clutch engagement (slipping), which makes it wear.

Don’t treat it like a regular automatic gearbox because it’s not. You should always let the clutch engage fully in 1st gear when you are crawling in traffic. Also, don’t use the gas pedal to stop the car from rolling backwards on an incline.

III. The 6-speed Easytronic transmission (1.3 CTDI) is based on the M20.

You can expect the same problems (worn-out 6th gear bearing) as with the manual M20 and M32 gearboxes. Additionally, the actuator system is a different design than in the 5-speed unit, and there is less information about it available. To be avoided…

The 5-speed Easytronic transmission is based on the manual F13 or the F17 gearbox. Both of them are fine.

The bottom line is this:

If you’re mechanically inclined, you can get a used Astra H with the Easytronic transmission. If you’re not, it may be expensive to fix if it fails.

The only engines that had conventional automatic gearboxes were the 1.8L petrol and the 1.9 CDTi diesel cars.

These automatic transmissions experienced radiator failures in the Vectra C, Astra H, Zafira B and other Vauxhall cars from those years. The transmission oil cooler is integrated with the radiator in these cars. There have been cases of coolant leaking into the transmission oil circuit. If not caught quickly, the result is total transmission failure.

It looks like none of the automatic Astra H models is a good choice as a second-hand car…

1.6T – cracked 4th piston (Z16LET engines)

There have been cases of cracked pistons in these engines. To make it more interesting, it’s only piston no. 4 that cracks.

Obviously, a failed piston is a pretty big problem and will cost a lot to sort out. It’s not standard maintenance and not something you’d ever expect to happen to your car. I think the piston problem is caused by a combination of factors so let’s review what we know first:

• Most of the piston failures happened in the 192 PS Z16LER engines used in the Corsa VXR. Out of these, the majority were tuned cars. Stock engines can fail too, just less often. The percentage of Z16LER/Z16LET engines that fail isn’t large, so there is no need to panic. Well… You can start stressing out if you’re running over 200 PS with stock fuel injectors… By the way, the Z16LER is the same engine as the Z16LET – the difference lies in the ECU settings. The Z16LER is simply tuned for more power.

• The fuel injectors in these engines are just adequate for around 200 PS. If you ask for any more power, the injectors will max out before reaching the top of the RPM range. A maxed out injector cannot deliver the amount of fuel required and the air-fuel mixture will become leaner as the RPM goes up under full load. Lean mixture = excessive heat = cracked piston.

• The pistons are cast and not very durable, otherwise, they would not crack (duh!). People who tune these engines with stock injectors risk breaking their 4th piston. When it goes, they usually replace all pistons with stronger, aftermarket forged ones. This solves the problem.

• Many of the Corsa VXR buyers were below 25 years old. This age group is inclined to go berserk in a 192 PS VXR.

There must be another factor that makes only the 4th cylinder fail while the others are usually fine. I’ve got some ideas as to why it happens. Here they are (these are just speculations, not facts):

• The 4th fuel injector is the last in the fuel rail, which could make it go lean faster than the other three.

• The 4th cylinder is the one furthest away from the water pump. Perhaps, cooling of this cylinder is not as good.

• The intake manifold may distribute air unevenly and feed the 4th cylinder with a bit more air, leaning out the mixture.

• It could be detonation (knocking). 98 RON fuel is recommended by the manufacturer and this could be the reason.

I think it’s time to construct the case:

A young, excited driver has the engine in his car reprogrammed to deliver more power – as much power as the stock hardware can deliver. On a cold morning, he gets in the car and takes off with the tyres squealing, seconds after turning the engine on.

The stock injectors can’t keep up with the driver so the temperature inside the cylinders suddenly rises to dangerous levels. Because of the engine design, the 4th piston gets hit the hardest. The unlucky 4th piston, which was cold seconds ago, goes through a thermal shock. The sudden change in temperature causes high stress inside the relatively brittle cast aluminium alloy.

This is a perfect scenario for piston failure and indeed the piston goes pop! It may not crack immediately, but repeat this a few times and the piston will be on its way to piston heaven.

I think that a lot is down to the driver and how the car is treated. If you already own a car with the 1.6T, sell it quickly before the 4th piston explodes! Just kidding…

If you are worried and you want the engine to last, you should follow these directions:

• Do not tune these cars at all unless you are going to upgrade the injectors. Even with larger injectors, you are increasing the risk of failure.

• Never drive the car hard until the engine is warmed up. Always let the engine cool down before shutting it down. Don’t drive it hard in the last couple minutes before shutting it down and let the engine idle for 15-30 seconds before turning it off. This is good for the turbocharger too.

• Choose the higher octane fuel available in your country. This decreases the risk of detonation.

If you follow the rules above, you should be fine, in my opinion. However, there will always be a very small risk that the 4th piston will go pop. This applies even to unmodified cars as some have failed. These engines are not bad but keep in mind that they should not be abused.

The fuel injectors are small so engine tuning is not advised unless the injectors are uprated. You may get away with stock pistons and a remap but I would not take the risk. You are safer leaving the engine at 180 PS.

If you are going to buy a car with the 1.6 Turbo, look out for the symptoms of piston problems: rough running or misfires, unwanted engine noises, increase engine smoke, lack of power. Also, try to find out if the car was not abused by the previous owner.

1.8 125 PS – timing belt (Z18XE engines)

The original timing belt replacement interval for the 125 PS 1.8L Z18XE engine was 60,000 miles. At some point, Vauxhall revised their recommendation to 40,000 miles, most likely because of a high number of failures. So, check if your car isn’t due for a timing belt replacement!

If you are planning to buy a Vauxhall / Opel Astra with the Z18XE engine, establish when the cambelt was last replaced.

As for the newer 1.8L 140 PS Z18XER, the timing belt replacement interval is 100,000 miles or 10 years according to Vauxhall. This is quite optimistic, but I don’t have any concrete evidence to contest this number. Personally, I would not keep the original timing belt this long in any car. The life of the engine depends on this piece of rubber.

I’ll leave this to you to decide. The main difference in terms of design is that the Z18XER has the water pump driven by the auxiliary belt and not the timing belt like in the Z18XE.

1.3 CDTi – timing chain (Z13DTH engines)

The 1.3 CDTi was an engine designed by Fiat and General Motors (mostly Fiat) when the two companies formed a partnership. It’s not a bad unit since Fiat is the godfather of Common Rail diesel engines. In Fiat cars, this engine is known as the 1.3 Multijet. “Multijet” stands for multiple fuel injections per combustion cycle.

The only major problem with this little engine is the timing chain.

The camshaft in this engine is driven by a single row timing chain not much bigger than a bicycle chain. In my opinion, it’s not a very robust design and an area to watch.

Generally, when a timing chain is used, the intention is for it to last the “lifetime” of the engine (very roughly 200k miles). Therefore, there is no replacement interval specified for the timing chain. As I see it, trying to reach 200k miles on the original chain and tensioner is very risky.

If the chain wears and elongates (stretches), or the tensioner stops working properly, the typical symptom that develops is a chain rattle that lasts for a couple seconds after a cold start. In severe cases, the chain noise may remain for longer after the engine has started. The “Check Engine” light may appear too.

Here’s what timing chain noise sounds like:

Any chain stretch symptoms should not be ignored in this engine, regardless of the mileage. If the timing chain jumps some teeth, you will be looking at valvetrain damage. You may choose to replace the timing chain preemptively like you would with a timing belt, or you can wait until symptoms develop.

In my opinion, engines that have done more than 100k miles will probably qualify for a full timing chain service (new timing chain, guides, tensioner and gears).

If you are looking to get one of these cars, make sure there is no chain rattle after starting the engine. This needs to be a cold start when the car has stood still for a couple hours (ideally overnight). If the chain rattle is persistent, it means the chain or the tensioner is on its last leg.

1.9 CDTi – swirl flaps (Z19DTH and Z19DTJ engines)

Just like the smaller 1.3L diesel engine, the 1.9 CDTi was designed by Fiat and General Motors. In Fiat cars, this engine is known as the 1.9 Multijet.

These engines use swirl flaps in the intake manifold in order to improve emissions. There are two types of intake manifolds that were fitted to these engines. Here’s a brief description of the manifolds and how they can fail:

1. Plastic manifold with spot-welded, stainless steel swirl flaps. Failure mode: the main cause of flap failure is increased friction in the flap mechanism from the carbon build-up in the intake manifold. Carbon build-up is a byproduct of the Exhaust Gas Recirculation (EGR). EGR systems are commonly used in modern diesel engines to improve emissions. The metal swirl flaps often keep working without any indication of a problem until the spot welds give up and a flap gets detached. It can then enter the engine causing severe damage. An ingested flap can take out valves, a piston, damage the cylinder walls and even the turbocharger.

2. Aluminium alloy manifold with plastic swirl flaps. Failure mode: the flap bearings can wear out from increased friction when the carbon build-up in the intake manifold becomes severe. Once the bearings are worn, they may develop an air leak, allowing the boost pressure to escape. Also, the flaps can simply get stuck before the bearings wear out. These plastic flaps are the lesser evil as they don’t break off.

The Z19DTH and Z19DTJ  have the safer aluminium manifold with plastic swirl flaps. Stuck or leaking swirl flaps manifest as rough engine running, reduced fuel economy and reduced power. The “Check engine” light may turn on.

To fix the swirl flaps, a new intake manifold is required, which is fairly expensive. Another option is to remove the swirl flaps altogether, which has a minimal impact on the engine running. There are swirl flap removal kits available on the market. Please be aware that removing the swirl flaps will increase emissions and is probably illegal – it depends on the country you live in.

1.9 CDTi – timing belt (Z19DTH and Z19DTJ engines)

According to the manufacturer, the timing belt in this engine needs to be replaced every 100,000 miles or 10 years, whichever comes first. In my opinion, this is very optimistic. I recommend getting it replaced not later than 60k miles or every 5 years, whichever comes first.

The water pump must be replaced at the same time as the timing belt, otherwise, it can seize and cause the timing belt to snap. It’s actually the water pump that is the weak point in the timing belt drive and the first part to fail.

Summary of problems & additional information

• The 2.0 Turbo engine is a proven unit with potential for increasing torque and power. By the way, the Z20LEL and Z20LER are both the same engine. The 30 PS difference in power output comes just from software. On the other hand, the 240 PS Z20LEH has forged internals, oil jets that cool the underside of the pistons, a larger turbocharger, higher flow injectors and a stronger clutch. Still, both the Z20LEL and Z20LER can be remapped to reach a similar output as the Z20LEH. Basically, it is possible to take the 170 PS engine to about 235 PS with just a software update. That’s +65 PS from a remap alone!

• It’s a similar story with the 1.9 CDTi engines. You should be able to get the 120 PS 8-valve engine (Z19DT) to produce 170 PS with just a software update. Just make sure that your clutch and gearbox are in good shape before cranking up the power. The 150 PS 16-valve engine can also be remapped, and you should be able to reach 190 PS or very close to that figure. What I find funny is that it should be possible to take the 120 PS Z19DTJ to 190 PS as well because both the Z19DTJ and Z19DTH are the same engine. That’s +70 PS from a remap alone. Happy days!

• The following engines were mated to the M32 /M20 gearbox: 1.6 Turbo (Z16LET), 2.0 Turbo (Z20LEL, Z20LER, Z20LEH) and all diesel engines except for the 1.7 CDTi, which was also available with a 5-speed gearbox. You can get the 1.7 CDTi with a 6-speed M32 gearbox too, but it doesn’t make any sense to do so.

• The naturally aspirated petrol engines are simple and reliable (and a bit boring). The only thing to look out for is camshaft adjuster rattle after a cold start in the Z16XER (1.6L) and Z18XER (1.8L) engines. Read this article about timing belts for a more detailed explanation.

• IDS+ shock absorbers are expensive to replace when they fail. Luckily, their life expectancy is good.

• Click here for an article that might help you decide if a modern diesel engine, like the CDTi, is the right choice for you.

• Not all diesel Astra H models have diesel particulate filters (DPF). It depends on the body type and whether the transmission is manual or automatic. In the UK, the 3- and 5-door hatchbacks with manual transmissions should not have one. In other countries, it may be different. Don’t rely on this information alone – get the Vehicle Identification Number (VIN) decoded to be sure. You can also check the label on the B-pillar (driver side). If the number inside the little square is 0.50 then the car has a DPF.

• The Fiat’s 1.3 Multijet… I mean the 1.3 CDTi may have problems with the timing chain. While the larger 16-valve 1.9 CDTi (also Multijet) likes to swallow swirl flaps and has a water pump that may fail prematurely.

• The 1.7 CDTi is made by Isuzu, which is a Japanese company. If you’re looking for the 1980s diesel experience – get the 80 PS Z17DTL. It has a decent 5-speed transmission, no dual-mass flywheel and no diesel particulate filter. It’s simple, slow and reliable. The more powerful variants are okay too, except for the ones with the 6-speed M32 gearbox.

• The 1.9 CDTi comes in three flavours – the 8-valve 120 PS Z19DT, which is my favourite because it doesn’t have any stupid swirl flaps. Then there are the 16-valve 120 PS Z19DTJ and 150 PS Z19DTH. Both are the same thing. The 30 PS difference comes from the engine map. The 120 PS 16-valve Z19ZDTJ engines were only fitted until 2006.

• Rumour has it that when the Astra H was introduced, Vauxhall (and Fiat) could not keep up with the demand for the 120 PS 8-valve engines. Therefore, they decided to use the 16-valve units and detune them to 120 PS. Eventually, production caught up and they were able to replace the detuned 16-valve Z19DTJ engines with the 8-valve Z19DT units. At least that’s what one of the automotive legends says.

• The automatic transmissions experienced radiator failures in the Vectra C, Astra H, Zafira B and other Vauxhall cars from those years. The transmission oil cooler is integrated with the radiator in these cars. There have been cases of coolant leaking into the transmission oil circuit. If not caught quickly, the result is total transmission failure.

• As for the Easytronic transmission, it’s not bad but it might be expensive to fix when it fails because it isn’t common. Not many garages have experience working with them, and going to the dealership with a faulty Easytronic gearbox will most likely result in a large bill.

Petrol engines – specs & performance figures

Diesel engines – specs & performance figures

Petrol engines – technical details

Diesel engines – technical details