Oil consumption
Another possible serious issue of these engines is the excessive oil consumption. It can appear before 150 000 km, but sometimes even before 100 000 km. This issue can be caused by 5 things basically:
1. Faulty PCV = The simplest and cheapest cause is the faulty PCV. I already talked about it – so you will have to replace either just the membrane itself or the whole valve cover.
2. Worn valve stem seals = The worn valve stem seals can often cause oil consumption too. This is easy to check, since in this case you will see blue smoke from the exhaust when you rev up the engine after idling for a while. (Worn valve stem seals symptoms: oil consumption + blue-ish smoke from the exhaust when driving off after idling for a while)
how to replace valve stem seals video
3. Clogged piston rings = The piston rings can cause oil consumption as well – they will simply clog up with carbon. This you can’t really check and to fix it you will have to disassemble the whole engine basically, which is not easy nor cheap.
4. Worn cylinder walls = In the worst case the oil consumption is caused by worn cylinder walls. This is the most expensive repair, since you will have to overhaul the whole engine or replace it completely. The only good thing about this is, that you can check the cylinders with an endoscopic camera and hope for the best.
5. Worn timing chain = And lastly it seems like that a worn timing chain can cause oil consumption as well. Because surprisingly, numerous owners got rid of oil consumption after replacing the timing chain. It seems like this phenomenon does have something to do with excess vacuum caused by bad timing:
“Timing is incredibly important in the function of engines. When motions are not perfectly harmonized between the valves and pistons, a vacuum can be created that draws large quantities of oil into the combustion chamber, causing very high consumption. One cause that can lead to the timing being off between valves and pistons is worn timing gears, which throw off the valve and crankshaft timing and create a large amount of backlash.” link
If you are replacing the timing chain, then you should replace the valve stem seals at the same time and vice versa, since the valve stem seals are gonna be worn and hard anyway!
Oil / coolant leaks
The oil can start to leak from:
- valve cover gasket
- o-ring of the upper turbo pipe (by the way there is also a lower turbo oil pipe which can most probably leak over time as well, because of the o-ring of course – but it seems like that this one doesn’t leak that often as the upper)
- vacuum pump on the back of the engine – in this case you will not only see the leak on the back of the engine, but most probably even smell burnt oil too. To fix this just replace the vacuum pump. (Because of the lack of space at the back of the engine it’s not that easy to replace it, but it is doable)
- oil pressure sensor – another thing on the back of the engine which can leak. The sensor is bolted onto the oil filter housing and it can leak not only from the o-ring but also internally from the pins, so if it’s leaking replace it completely.
- oil cooler – also mounted onto the oil filter housing. This can leak oil as well, but keep in mind that not all of these engines are equipped with an oil cooler – some weaker versions don’t have it.
- oil filter housing itself – The gaskets of this housing are gonna inevitably fail and leak. The gaskets are cheap but replacing them is not the easiest, since you have to remove part of the exhaust-the cat, to access the housing.
- the 2 metallic plugs on the front of the engine around the front crank pulley can sometimes slightly leak oil
- the front crankshaft seal can leak too
- + as a bonus check also the oil pump solenoid wiring on the lower side of the engine which can sometimes leak oil as well
The coolant can start to leak from:
- coolant temperature sensor body located behind the engine (visible coolant leak on the gearbox) – in this case mostly just the o-ring of the coolant temp sensor leaks, but there are other 2 gaskets which can leak too. You can buy the temp sensor o-ring separately, but it’s better to replace it together with the housing and the coolant hose.
- 2 o-rings on the side the turbocharger – very cheap and easy fix
- under the turbocharger there is a mettalic coolant pipe which is connected to the engine block thru a small mettalic cross piece. The o-rings on this connecting cross piece will fail and leak, so be ready for this + to top of that there is also a short rubber hose connected to the mettalic coolant pipe which can leak too
- the thermostat will leak and eventually fail – this part looks like a cheap plastic garbage which will inevitably crack and disintegrate, so be ready to replace it. To top of that, it’s pretty hidden under the intake manifold on the side of the engine so replacing it is not the easiest, since you have to remove the engine ECU plate, the intake manifold + obviously the small trash around (faulty thermostat symptoms: engine doesn’t reach operating temp, insufficient heating, higher fuel consumption)
- the water pump will fail too – in many cases it usually just develops bigger play while making noises, but of course it can also leak
- the coolant tank itself can crack and leak + it’s good to replace the coolant tank cap preventively = long story short, this cap also acts as a pressure relief valve → this small mechanism in it can get stuck → which will cause excessive pressure in the cooling system → which will cause the various coolant leaks earlier then they would normally occur.
Other stuff
To end this long, looooong list there are a couple of last things related to these engines so:
-the oil dipstick often breaks
-the exhaust side Vanos solenoid can fail more often causing various symptoms like: lack of power/loss of power, error message on the screen, fluctuating idle, Vanos related fault codes. However there is also an intake Vanos solenoid on the other side of the engine which can sometimes fail too.
–throttle body failures can occur as well, causing various symptoms: limp mode/loss of power, various error messages, throttle body related fault codes stored.
-the regular low pressure fuel pump failures are also not uncommon mainly in cars used in countries with bad quality fuel, but the relay of this pump can fail too – so if you are replacing the pump then replace the relay at the same time too ! (The low pressure fuel pump is located under the rear seats in the fuel tank)
-since these engines are equipped with direct injection you should expect issues with injectors, hpfp, and with carbon build up
Injectors
Clogged/faulty injectors are gonna have bad spray pattern which will cause misfires, but in the worst case over time they can damage the cylinder walls or even the pistons.
Symptoms of bad injectors:
- random misfires-slightly fluctuating idle/slight vibration at idle
- jerking during acceleration
- not good engine start
- higher fuel consumption
- they can let some amount of fuel into the oil too
- in the worst case they can also cause the piston to crack – but mostly just in cars with performance upgrade
So generally speaking it’s a good idea to check/test/clean or simply replace the injectors at around 200 000 km, but in countries with bad quality fuel the injectors can start to fail even at around 100 000 km.
That would be it. I guess?
As you can see it really seems like everything can and will fail on these engines, but let’s not be that negative. Even though many of these issues can occur before 100 000 km and even though I would not buy a car with this engine, this horrible looking list doesn’t mean that you will experience all of these issues and definitely not at the same time.
But it’s still better to keep in mind that these are not the most reliable engines in the world, even though with proper maintenance you can minimize or even eliminate many of the issues so:
- change the engine oil every 8000 km
- change the spark plugs every 40 000 km or maximum 60 000 km
- use premium fuel eventually additives
- check/test/clean or simply replace the injectors at around 200 000 km, but in countries with bad quality fuel it’s better to do this at around 100 000 km
- check and eventually clean the intake valves from carbon every 100 000 – 120 000 km
- check the timing chain wear at 100 000 km or after buying
- keep in mind all the weak spots
- it’s better to avoid engines with performance upgrades since this tuning increases the risk of cracked pistons, yes this can occur too
