Vauxhall / Opel Astra (J: 2009-2018)

M32 gearbox bearings

Some Vauxhall Astra J 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 M32 gearbox is used in so many vehicles and bearing failure is so common in high-mileage vehicles, that I’ve dedicated a full page to the 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 gearbox is used in the following Vauxhall Astra J models:

• 1.4 Turbo (A14NEL, A14NET, B14NEL, B14NET)

• 1.6 Turbo (A16LET)

• 1.6 SIDI Turbo (A16XHT, A16SHT, B16XHT, B16SHT)

• 1.6 CDTi (B16DTL, B16DTH)

• 1.7 CDTi (A17DTJ, A17DTC, A17DTR, A17DTS)

FlexRide shock absorbers (CDC)

Continuous Damping Control (CDC) is 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.

The CDC is an optional extra in the Astra J, and it’s fitted to cars with “FlexRide” suspension.

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, you will be looking at around £350 for a new FlexRide 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 CDC shock absorbers reconditioned for half the price of a new one. There are companies that specialize in these kinds of jobs. It isn’t possible to simply disable the CDC like in the older Astra H.

Therefore, it isn’t as straightforward as before to fit aftermarket, conventional shock absorbers. It is possible mechanically, but the car’s computer has to be tricked into thinking the CDC is working. This can be achieved by using an aftermarket emulator device. Like I said, it’s not straightforward at all. Keep this in mind when buying a high-mileage Astra J with FlexRide.

1.4 Turbo – PCV valve failure

Before I get to the point, let me briefly explain what the PCV valve is.

The positive crankcase ventilation system (PCV) is present in every modern vehicle, and its purpose is to evacuate crankcase gases generated by piston blow-by. These gases are fed back into the engine through the intake manifold, and without the PCV system, the engine crankcase would pressurize.

The PCV system is usually made of pipes, channels and chambers that separate oil from the blow-by gas. The only moving part is the PCV valve, which is just a one-way valve that controls the amount of gas being fed into the intake tract.

One important thing to know is that in petrol engines, the intake manifold is under vacuum when the engine is idling or under low load. This is because of the throttle plate that restricts the amount of air entering the engine.

At low loads, the throttle plate is mostly closed and the engine is trying to pull more air than it is allowed to, which generates a vacuum between the throttle body and the engine itself. This vacuum sucks the crankcase gases through the PCV valve.

There is also another air pathway between the engine and the air intake. This one is connected to the intake before the throttle body and its where the blow-by gasses go when the throttle plate is open (full throttle) and there is very little vacuum generated in the intake manifold.

In a turbocharged engine, the PCV system is more complex because the turbocharger generates boost pressure. Hence, the intake manifold is pressurized when the turbocharger is doing its thing.

In these conditions, blow-by gasses are fed into the intake duct before the turbocharger. However, when there is no boost, the system operates exactly the same as in a naturally aspirated engine.

I hope I made this reasonably clear. Now, let’s get to the point.

The PCV valve is usually a tiny, £20 part attached somewhere near the engine valve cover. The General Motors 1.4 Turbo engine has two PCV valves – one is integrated with the air intake manifold and the other one is at the turbocharger inlet.

There is also a rubber diaphragm inside the valve cover that regulates the flow of gases. To sum up, there are thee key components in these engines – two PCV valves and the rubber membrane in the valve cover.

The intake manifold PCV valve in the 1.4 Turbo engines is a rubber membrane that resembles a… nipple. It covers a series of small holes. When there is no boost generated by the turbocharger, the membrane gets pulled away from the holes and lets the crankcase gasses enter the intake manifold. Under boost, this valve is closed and the one at the turbo inlet opens.

The problem is that the PCV valve inside the intake manifold sometimes gets detached and swallowed by the engine. A detached PCV valve isn’t going to damage the engine because it’s only a little piece of rubber, but the boost pressure entering the engine valve cover and crankcase will quickly damage the diaphragm in the valve cover.

In other engines, replacing the PCV valve is a 10-minute job and a new valve typically costs £20 or less. In this case, you have to replace the entire intake manifold when the PCV valve inside fails. If it’s the vacuum regulating rubber disc in the valve cover that failed, you will need to replace the entire valve cover (luckily, it’s not expensive).

If you are experiencing any problems with the PCV system, it’s important to check all three key components – both PCV valves and the membrane. A PCV valve failure will cause the valve cover diaphragm to fail soon after. When inspecting these parts, also look for air leaks.

Typical symptoms of PCV system failure:

• excessive oil consumption, blue smoke may be coming from the exhaust pipe

• hissing sound in the engine bay (valve cover sucking in air through an opening where the membrane is)

• intermittent Check Engine light, possible error codes: P0106, P1101, P0236, P0107

• rough, unstable engine idle and poor performance

• oil leaks (boost pressure entering the engine can force oil past engine seals)

Luckily, it’s relatively easy to check if the PCV valve and the membrane disc in the valve cover are okay. First, you need to remove the plastic engine cover. Then, with the engine running, check if the engine doesn’t suck air in through the valve cover membrane housing. If it does, you will need to replace the valve cover as the membrane in it has failed.

As for the intake manifold PCV valve, with the engine off, remove the hose going to the PCV valve in the manifold. Shine a light inside the manifold and see if the PCV valve is still there. If you can see the nipple, it’s fine. The locations of these parts are marked on the photo below.

Apparently, the intake manifold was updated in 2011 to improve the reliability of the PCV system, so if you’re planning to buy a 1.4 Turbo Astra J, look for a 2012 or newer model – one with the updated M32 gearbox as well.

1.6T – cracked 4th piston (A16LET 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 1.6 Turbo 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 engines that fail isn’t large, so there is no need to panic. Well… You can start stressing out if you’re running over 200hp with stock fuel injectors…

• The 192 PS Z16LER is the same engine as the 180 PS Z16LET – the difference lies in the ECU settings. The Z16LER is simply tuned for more power. The A16LET is a newer version of the Z16LET, and it’s almost identical, except that it has variable valve timing to reduce emissions – the engine internals are the same though.

• 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 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 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.

1.6T SIDI & 2.0T SIDI  – carbon build-up

Direct petrol injection systems, like the Vauxhall SIDI, are prone to carbon build-up on the engine intake valves. Excessive carbon build-up can reduce power, increase fuel consumption and make cold starts difficult. The “Check Engine” light may appear too.

Carbon build-up is a common problem for many direct injection petrol engines as the fuel is no longer injected into the intake manifold where it has a chance to wash away any carbon build-up from the intake valves.

Fortunately, The SIDI engines developed by Opel / Vauxhall have relatively few problems with carbon build-up, at least at low mileage. Keep in mind that at some point, there will be some build-up, and if it becomes severe, the only option is manual cleaning. This requires the intake manifold to be removed.

If you do lots of motorway driving and like to drive hard, you’ll probably be okay for quite a while. However, if you’re doing lots of short trips, then carbon cleaning may be on the horizon. Anyway, carbon-build up is not a massive issue with Vauxhall / Opel SIDI engines. Just watch out for symptoms of carbon build-up in high-mileage cars.

The only two engines with direct injection in the Astra J are the 1.6T SIDI & 2.0T SIDI. The 2.0T SIDI was used in the Astra VXR (or Astra OPC outside of UK).

The carbon deposits come from the Crankcase Ventilation System (CVS), which is connected to the intake. It’s a common design in most engines. In any piston engine, a small portion of the gases from the combustion chamber is blown past the piston rings into the crankcase. These gases contain oil vapour (hydrocarbons) and combustion by-products (more carbon).

From the crankcase, they are fed back into the engine through the intake manifold, where they form deposits. Also, there is the Exhaust Gas Recirculation (EGR) valve that redirects a portion of exhaust fumes back into the engine intake (even more carbon).

Detergent fuel additives don’t really work in direct injection engines as the injected fuel doesn’t go over the intake valves like in the older manifold fuel injection systems. Therefore, it doesn’t have a chance to wash away the carbon deposits. Sooner or later, all direct injection engines will have some carbon build-up. It is inevitable, Mr Anderson.

As a side note, there is a way of eliminating carbon build-up in direct injection engines. It requires additional fuel injectors that can wash off the gunk from the valves – a dual injection system. This is where direct injection technology is heading.

1.3 CDTi  – timing chain (Z13DTE 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 the 1.3 CDTi, 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.

Summary of problems & additional information

• The 5-door model was produced between 2009 and 2015, while the 3-door GTC model, including the VXR / OPC, remained in production until 2018.

• There are reasons to celebrate – the M32 gearbox received an update in 2012. With larger bearings and extra oil channels, the cycle of twitching gear levers and bearing replacements is finally over. Long live the updated M32 gearbox! I don’t know if I have to state the obvious, but if you are planning to buy an Astra and the model you like is fitted with the M32 transmission, make sure you get a car with the updated gearbox.

• The following engines were mated to the M32 gearbox: 1.4 Turbo, 1.6 Turbo, 1.6 SIDI Turbo, 1.6 CDTi, 1.7 CDTi.

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

• All petrol engines in the Vauxhall / Opel Astra J have variable valve timing (VVT). When buying a petrol-powered Astra, look out for camshaft adjuster rattle during a cold start. Read the article about timing belts and chains for a more detailed explanation.

• The 1.6T (A16LET) comes with a small risk of 4th piston failure. Most cases were limited to the 192 PS Corsa VXR / OPC, however, some 180 PS engines popped their 4th piston as well.

• The 1.4L Turbo is a good unit. A timing chain is a bonus (provided you buy a car in good condition that doesn’t rattle when started). The only issue with these engines is a complicated PCV system with too many plastic and rubber parts. As these rubber and plastic parts age, we are likely going to see more PCV system failures.

• There is no physical difference between the 120 PS and the 140 PS variants of the 1.4 Turbo engine. The extra 20 PS comes from a different engine map.

• As for the naturally aspirated petrol engines, they are simple and a bit outdated, which is a good thing for reliability! If you just a want a reliable commuter car and don’t care about acceleration, these are the engines to get.

• Carbon build-up on the intake valves may be a problem in high-mileage, direct injection (SIDI) engines. The only two engines with direct injection in the Astra J are the 1.6T SIDI & 2.0T SIDI.

• Follow this link for an article that might help you decide if a Euro 5 diesel engine, like the CDTi, is the right choice for you. Because the Astra J was released at the time when Euro 5 emissions standards came into force, all diesel engines have diesel particulate filters (DPF).

• The Fiat 1.3 Multijet… I mean the 1.3 CDTi may have problems with the timing chain in higher-mileage cars. The 2.0 CDTi engine also has Fiat roots (and a timing belt).

Petrol engines – specs & performance figures

Diesel engines – specs & performance figures

Petrol engines – technical details

Diesel engines – technical details