The great big MK6 Golf 118TSI tuning thread

[The_Hawk]

I stumbled across this thread in another forum (see the source at the bottom) and wanted to share. There is actually a number of good posts over there by this guy that are worth reading:
SEAT Cupra.net - SEAT Forum

LUCIFER'S ULTIMATE GUIDE 1: FUNDAMENTAL PROBLEMS

[PICS TO FOLLOW]


Hello twincharged owners. My name is Mark.....aka Lucifer and I have spent the last 4 years in ownership of a 1.4tsi Seat Ibiza. I have now at long last managed to conquer stage 3 tuning on this engine after several setbacks and much more money spent than I ever wanted. I still honestly believe after all the inerrant problems I have discovered with this engine and products designed for it by certain company’s, that the engine can still be tuned on a budget and can be reliable. Hence this guide........hope you all enjoy.


FUNDAMENTAL PROBLEMS WITH THESE ENGINES:

1. Misfiring, Oil Consumption, Engine Failure
2. PCV System
3. Turbo
4. Timing Chain
5. Radiator
6. Supercharger Magnetic Clutch

.

[The_Hawk]

and some more:

1. Misfiring, Oil Consumption, Engine Failure

This is the main worry for most 1.4TSI owners. Its not because of a single problem, but involves a number of factors which together they ultimately lead to engine failure.



A) Piston Rings

After it was finally admitted in late 2011 that there was a problem leading to engine failure(bearing in mind the engine came out in 2010), SEAT offered customers new piston rings.
Actually, what they were doing was fitting completely new pistons. It was VW trying to delude the customer that it was a minor piston ring batch problem rather than a major piston design problem.
In truth, its the pistons that were weak full stop and couldn't handle much punishment before they failed. The specific problem was that the part of the piston between the rings used to crack and then come away, damaging the piston rings and eating into the cylinder bores (although these have proven to be very strong due to being plasma coated).
There have been examples of totally standard cars having piston failure and these tend to be early cars with the original ignition hardware and OEM ECU software. Then when you add an ECU map you are bound to have a failure.
When these pistons crack, oil consumption is increased as it enters the combustion chamber, also lowering the effective octane value of the fuel being injected. This is not the only reason for oil consumption and equally the culprit is the turbocharger, especially on cars with aftermarket exhausts. I will talk about that later.
Its easy to blame the pistons but its not the whole story. If the car was used for daily driving and not running massive amounts of boost, there’s no reason why these pistons should be put under such an amount of punishment that it would result in failure........unless there are other contributing issues, which there are. Read on.........

Solution: Revised pistons 2012 onwards and come as standard in the CTHE/CTHF engine codes.



B) Ignition System

Injectors
These were problematic at the end of 2009/start 2010.
They would drip when stationary with the engine off causing oil to be washed off the bores and pistons, resulting in increased piston ware. Upon starting the engine, the engine would run lumpy because of the extra fuel in cylinder.
Another feature was a narrow spray pattern to the injector. This would result in an incomplete burn when fuelling is at its highest and the excess would collect on the surface of the piston, which would then ignite due to the heat of the engine. This would scorch the surface and cause carbon build up which collected on the exhaust valves. This would cause misfiring due to valves not shutting correctly. The crazy part is that by driving the car hard under boost then it would clean away enough carbon to allow normal operation without misfire but would also speed up the failure process.
When re-maps started getting released as fuelling was increased it was exaggerating the problem. This coupled with the weak pistons discussed earlier resulted in the early engine failures.

Solution: Revised Injectors with a wide spray pattern got released by SEAT mid 2010, chances are most cars have these now, which lead to other problems.

This new problem was at full fuelling the wide pattern would extinguish the spark of the spark plug which is sat almost directly in line with the injector. It is because this 1.4TSI engine is actually based on the old 1.4 16v engine from years ago so that wasn’t addressed. It was Revo Technik that actually discovered this after they had a piston fail when developing their stage 2+ map, subsequently falling out with SEAT. They then halted their development of this engine but came out with a couple of recommendations which I shall discuss below.

Coil Packs
There were a batch of coil packs in 2010 that were faulty according to SEAT but again I believe that was an excuse to make them look less liable for their problems.
There were a later version of the coil packs in 2011 which again the CTHE/CTHF engines have as standard. I believe the aim was to increase the strength of the spark created by the plugs in order to try and stop the misfiring. From my experience these helped very little as the cause of the problem was still existent.



Seat Software+Spark Plugs+High Presure Fuel Pump
This is the main cause of the engine failures since 2010.
So as we know we have the weak pistons and new injectors with a wider spray pattern causing contamination of the spark plug tip.

One other thing I haven’t mentioned yet is the Software. When the engine was re-released as a performance engine in 2010, it coincided with new emission regulations. The pre 2010 variants under the old emission regulations had the same power output as the new FR (150) and engine failures with these were rare; yet the FR failures were as common as the CUPRA (180bhp) variant so it was nothing to do with the increased power output.
It was as a result of the software which ended up making the engine run a lean mixture when not under boost in an effort to meet these regulations.

As it stood, the engine itself ran hot due to its twincharged nature.
Pre detonation was therefore a problem. Fuel was ignited as a result of the heat build-up rather than the activation of the spark plug which, as was mentioned above, was not fully operational under high fuelling instances. So this was throwing timing out when booting the car after gentle driving/traffic situations, the spark plug was then firing without any fuel to ignite making the problem worse. This resulted in engine misfire and stutter until fuelling was increased enough to the extent that it was contaminating the spark plug as we discussed. The fuelling therefore went through cycles of being too lean and too rich.
There were further problems as a result of the ECU software. There were some floored parts of coding in the software that couldn’t control misfiring properly, which is so hard to believe when dealing with such a well established company such as VW. Revo again were the first to inform me of this parameter within the code.

Because the fuelling system is a 'demand' type, air quantity is measured and the correct amount of fuel is then supplied for the desired mixture(as set in the ECU). So when a misfire occurred, the ECU had no comprehension that the engine could possibly be running rich as a result of the misfire, only lean. It would then start increasing fuelling constantly expecting the misfiring to stop, to the point that the engine would completely stall and the cylinders were full of fuel.
This fuel would leak into the sump and mix with the oil which is detrimental to its function. This is another catalyst to the engine ware.
Revo found that cylinder 4 on the other hand, being the last cylinder to be supplied fuel along the common rail fuel supply, was starved of fuel. This is because the capacity of the fuelling system was max'd out; injectors 1, 2 and 3 were at full flow and there wasn’t sufficient fuel left to be able to supply injector 4. This lead to piston 4 being the one that failed in most cases.
SEAT released a new High Pressure Fuel Pump towards the end of 2011 as an attempt to stop the cylinder 4 starvation of fuel, which may or may not have helped, but didn’t address the cause of the problem.
Now when you have a serious bout of misfiring it is obvious, it is felt throughout the car and lights appear on the dash. The majority of the time, the engine would have invisible misfiring. When I logged the car, I found that misfiring was present constantly but not so bad as to be detectable. So this problem was going on to this degree undetected for a lot of cars, leading to piston 4 finally going.

Revo actually took it upon themselves to rewrite this part of the coding, which isn't the norm. Usually they just re configure boost pressure, Air-Fuel-Ratios, timing etc. After this was done people, including myself who were totally standard before, flocked to Revo just for a car that would work properly. It took SEAT several months after this to release software that would solve this problem but of course they still needed to abide by the new EU regulations which REVO didn’t.

In addition to the amended software, Revo also recommended a plug change to NGK Iridium BRK7EIX. This plug was shorter and colder so it sat out of the way of the flow of the injectors whilst reducing pre detonation. Again there is a disadvantage of these plugs. It is more difficult to create an efficient burn, especially on cold start-up. There will be a lumpy initial idle because the plug is on the edge of its operating temperature zone.
Carbon build-up on the valves is still a problem too.
SEAT then released a new model of plugs for this engine to work with their software which are shorter than the original plugs which work with their new software; but not a re-map.

Solution:Revo/New SEAT software + recommended plugs.
The new fuel pump released at the endof 2011 is not necessary but is handy for tuning as I know its adequate for over 300bhp, where the other one may be not.
All the above upgrades will be available on the 2012 cars onwards.





Misfiring is still present with these engines regardless of all the new hardware and software. It will just be on occasion when the right environment is created:

1. High Carbon Build up on the valves restricting exhaust gasses leaving the engine plus carbon build up on the plugs restricting the quality of spark.
- Caused by long slow driving or not using the turbocharger for extended periods

2. High intake temperatures
- Caused by heat soak when in traffic with high ambient temperatures.

3. Lower quality fuel (95ron supermarket)
- Caused by being a tight ass
,

[The_Hawk]

and some more:

2. PCV System

Or Positive Crankcase Ventilation for those who want to know or care. Basically its job is to release pressure built up in the sump as a result of blow-by gasses entering from the combustion chamber.

This is completely normal even on engines with perfect piston ring seal but there will always be a certain degree of air escaping the cylinder past the piston rings into the sump.

The amount of pressure that ends up in the sump is proportional to the amount of revs the engine is at and also the amount of boost being used.

Once this pressure has been released through a hole in the block, then it is directed back into the intake to be re-used by the engine.

It used to be vented to the atmosphere on older cars but new cars have to meet more strict regulations.

It enters the intake side of the engine in 2 ways.
The first is just past the air filter which is a rather thick pipe and the other is straight into the intake manifold through a rather thin pipe.

There is suction or vacuum on these pipes created by the air entering the engine, which helps suck the crankcase gasses out.

These two pipes join together via a regulation check valve that controls which pipe it goes through.
This valve also controls back flow of the air to the engine once the throttle is released and there is no loner any vacuum provided by the intake system.

The problem with this system is that it is restrictive from the factory. The reasons for the restriction are the regulation check valve that we discussed and also a second check valve that exists inside the block. Before the gas leaves the block through the hole there is a what is called an oil labyrinth which separates any oil from the air trying to leave. Any oil collected drains back to the sump. It look almost like a maze. It has some narrowings and also a check valve after, it which is very restrictive.

So with these engines, whilst new and running standard mapping they shouldn’t produce blow-by sufficient, not to be vented by the PCV system. As we know though, once mapped and running more boost then blow-by increases but more importantly, should the pistons deteriorate because of either the early injector problem or the more recent software and spark plug problem, then blow-by will be higher too. This results in high crankcase pressures.

The problem is with this is that it puts pressure on the whole engine in relation to seals and gaskets. The turbo oil seal is the weakest of these so you would expect one of the seals either on the intake side or exhaust side to start weeping oil through.

The way this happens is that the oil return pipe from the turbo gets pressurized and oil is restriced from returning to the sump as it needs to.
At the top of the turbo, fresh oil is being supplied to the turbo via the turbo oil feed pipe. This results in the pressure of oil in the turbo being increased to the point it only has one way to go.......past the oil seals.

Should this issue not be resolved then the seal will get pushed out further and the car will smoke from the exhaust. A whitish colour to begin with but then a more bluey colour.

At this point the turbo will be consuming a good amount of oil and will need a rebuild.

If the car has a standard catalytic converter then the smoke is likely to be subdued and instead it is replaced by little black particles being accumulated over the back of the car and you will observe a glistening layer to the boot and rear bumper when raining.

The second problem with, high crankcase pressures is oil being pushed out through the pcv pipe into the air intake, which gets sucked into the engine again lowering the effective octane of the fuel. Thus pre-detonation is even more likely than when we discussed before and the carbon coating on the valves and spark plugs are even more likely.....misfire galore and bye bye piston.

Now of course it is triggered by bad pistons and or high boost with extended periods of hard driving (track) but there are a few other points to consider regarding the turbo supporting hardware that affect this. So if you do have a turbo oil leak it doesn’t necessarily mean you have bad rings, but if you are getting oil through the pcv pipes too then there is a good chance, especially if you are running standard software. I will talk more about the attributes of the turbo below but this is a major cause of oil consumption.

When my engine was rebuilt, it didn't use a drop of oil and had excellent compression yet the turbo was still leaking oil into the exhaust from pre build and I could use anywhere between 125ml to 250ml in 250miles, which if the car had been taken to SEAT for an oil consumption test, would have been treated to new pistons or a new engine as part of their guidelines. I wonder how many people that failed oil consumption tests have had this done.

The newer CTHE cars have a new pcv system and oil labyrinth to address this. They actually released this new breather pipe in 2012 because they realised that they were handing out new engines unnecessarily. Not only that, they could actually reduce and hide oil consumption by improving this pcv system, enabling them not having to address this issue until the car was out of warranty. In my opinion, whilst the new pcv pipe revision is an improvement, it does not address the internal restrictions inside the block.

To that end, I had to resort to removing the timing chain case and drilling the check valve out. This was only necessary because I was not only running a decat exhaust, hybrid turbo and high boost; but low silicone pistons also. These expand when warm and are at their tightest in the bores when hot and under boost which is what you want. Under idle on the other hand there was a lot of blowby which is just a feature of this type of piston.

I also deleted the small pcv pipe and the top check valve and designed a twin catch can system so not only was it more effective, it had the added benefit of having no oil in the intake.



Solution:
Custom catch can setup to catch any oil from the PCV system. (please see other guide)
Drilling out the internal engine check valve (If not CTHE and stage 3)

3. Turbo

The turbo is not necessarily an issue if it wasn’t for the known engine problems but there are 2 major features of this turbo that need consideration to avoid oil consumption.

The oil seals of the turbo are designed to hold the oil inside the turbo around the bearing rather than it leaking down the turbo shaft to the turbine and impeller (2 wheels at each end of the shaft). These are designed and balanced perfectly to take into account the forces applied on them in both directions. The internal force on the seal is made by the heat expansion inside the bearing and the oil pressure flowing through it. On the other side there is back pressure. On the intake side of the turbo it is the air hitting the wheel and the force of compressing the air to send to the intercooler. On the exhaust side it is the back pressure of the downpipe, catalytic converter, cat back pipe and silencers.

One rule of thumb with a turbo engine is that the best sort of exhaust is no exhaust at all; and no exhaust = no back pressure. Thus after market exhausts deliberately try and minimize back pressure, resulting in the oil seal losing the pressure balance it once had. On a normal car this is not usually too much of a problem and the seal could potentially hold the oil in with minimal seepage, but together with the second feature of this turbo, it simply cannot.

The second issue is the internal pressure inside the turbo. These turbos, as confirmed by their manufacturer, are designed with internal pressures of 40-60psi in mind. When measuring the actual pressure through the turbo even with a new engine it was found that it could raise to 70psi. This is because of the under piston oil jet system, which coats the pistons in clean cooler oil before they raise up into the bores for the next stroke. There are a few other manufacturers that have had similar problems.

Now if you imagine the engine and pcv problems being present as discussed earlier with high internal pressures and no back pressures then it becomes a very serious issue.

There is no SEAT solution to this problem as they don't want us to run sports exhausts to begin with, especially de-cat exhausts. I designed an oil restrictor bolt based on another VW variant. It has slightly smaller holes than the OEM one on the 1.4TSI and have I have logged the pressures at between 40-45psi. This results in a healthy internal pressure allowing a decat exhaust to be run safely with a healthy engine.

This is even more important to fit if you are using a hybrid turbo. The reason is the turbine wheel on the exhaust side is MUCH bigger and the housing has been bored out resulting in more flow but less back pressure. Thats great for performance but not good on the oil seal. For this reason, I have also had the oil seals strengthened in my hybrid turbo.



Solution:
Custom oil restrictor (if running decat)
Strengthened oil seals (as part of the turbo hybridization process)

NOTE: LOBA270 has normal oil seals, and is not suited to a de-cat exhaust, despite what they say!

[The_Hawk]

4. Timing Chain

The timing chain system is a known fault. The part that fails is the hydraulic tensioner which uses oil pressure to tension the chain. The cases that I am aware of have been when engines are running fine before being switched off, then not able to be turned over again. Having had direct information from a major race engine builder in the UK, this problem has occurred mostly after an oil change.

When the oil has been dropped and the car left over the pit until the sump is dry, the tensioner ends up being empty with no pressure on the chain, this is worse if an engine flush has been used. Upon starting the engine it will take some seconds before oil pressure inside it has been re-established and thus during cranking the chain is slack giving it an opportunity to jump. The older and more worn the timing chain, the more likely it is to jump.

There is no update or new part for this problem



Solution:
Regular services, ideally every 5-10k with the best oil you can afford that is 0W-40. If
not, 10W-40. Also when doing servicing, fill the oil filter up with oil before fitting and
don’t allow the sump to drain dry during the emptying phase of the oil change. Once it
starts trickling, put the sump plug back in and fill the engine with new oil.

5. Radiator

Another built in problem here. This tends to go at the 3 year point, coincidently at the end of the warranty period. It is Pretty bad quality. It uses plastic end tanks bonded to the metal core, and its this bond that comes apart allowing the radiator to start leaking water.



Solution:
At £90 these are quite cheap but can be upgraded to an Aluminium version with 78% larger capacity by Pace Products, which greatly helps in reducing block temperatures which we know are high.

6. Supercharger Magnetic Clutch

This problem occurred in cars built in 2010 and 2011. The car would make a squeak or ticking noise where the supercharger would struggle to engage upon trying to activate the supercharger at low rpm. The problem was a part of the water pump where there exists a magnetic clutch responsible for supercharger activation. The upgraded part had modified clutch material that solved the problem.

Some people had it replaced and the problem returned but I believe they just had a new outdated variant fitted which lead to the same problem.



Solution:
Upgraded water pump, standard on cars post 2011.

PART NUMBERS

I will be updating this section soon to include all the up to date part numbers and I will highlight the ones essential to solve the problems above or needed for tuning.

FINALLY

I hope this is useful for people who see the 1.4TSI as a mystery. I was one of these people to begin with. I have done my best to provide the most comprehensive and accurate account of these problems as well as all the solutions that are possible. The information gathered has been supplied by SEAT head technicians, ECU tuning companies, Performance engine builders, Turbo technicians and my own personal findings.

If there are any questions or comments that you feel the need to ask, please do.

LOOK FORWARD TO.............LUCIFERS ULTIMATE GUIDE 2: TUNING THE 1.4TSI

STAY TUNED

Source: Lucifer's ultimate guide: 1.4tsi fundamental problems - SEAT Cupra.net - SEAT Forum

[The_Hawk]

And the second part:

Ok, I'm back again after a rather mixed year of injury through to success (see another thread those who want to know)

I have managed to create the first successful stage 3 1.4tsi in the UK, arguably the fastest road legal one in the World. It is well over 300bhp at the moment and the final dyno and performance figures will be seen next year so keep your eyes open

This tuning guide will give even the most inexperienced person the understanding on tuning this car to be a giant killer. Not only that, it can be done on a budget. Again, all the information given is all correct and is based on all my own experience and the findings of reliable sources.


PRE TUNING WARNING

Make sure you have the updated parts highlighted in the first guide. These include the breather modification, injectors, coil packs, spark plugs, water pump and most importantly the pistons. I could not give advice with good conscious to map a car with the old versions a as they are ticking time bombs. Modifications that increase power through improving efficiency like intakes,intercoolers and exhausts would be OK to do and with all three on a stock car I gained 25bhp at the top of the Rev range.The cost vs reward though I would not say is worth it. You need a good remap to make the most out of these modifications.


REMAPPING: REVO VS APR VS CUSTOM

Custom

If you have any desire to go further than stage 2 then I would start with a custom map as there are no company's offering stage 3 maps off the shelf. Not only will it be customised to all your modifications but upgrades will be cheap and they will work with you to get the most out of your car. Most importantly, you need to find a tuner that does their mapping in house. Some get the car mapped remotely over the Internet or sub contract other mappers, problems occur with consistency of work quality and the fact the mapper never even sees the car he is working on.

AVOID: Shark Performance and AmD who don't do their own maps. Shark damaged a friends car and over stressed another friends turbo. AmD messed my DSG software up by trying to access it without the right security coding and sent it into safe mode which left me with only gears 1,3,5,7. They would not accept responsibility for it at all. My current tuner confirmed they had triggered an anti tamper device.

GOOD: Jabbasport; heard good things from every one of their customers

Revo Vs APR

The good thing about these is they both have alot of experience with this engine.

Revos early software was brutal and the fastest ever 1/4 mile was done on their stage 1 software. They later detuned their stage 1 after the problem with this engine came to light. Revo blew their piston in their development car working on stage 2+ software which they later found to be the fault of the vw fuelling management code. They re wrote this and along with different plugs cured the problem. People like myself came flocking to them just to get a reliable car.They called it quits with the stage 2 software and pulled all development on this engine. Revo now have employed someone to answer the phone so you can't get through directly to a tuner. If you ask her a question, she refers to a cheat sheet and basically reads off the information on there. Not what it used to be.

Apr worked on VSRy's hybrid 1.4tsi and unlocked a few secrets regarding torque limits which they managed to bypass. This unlocked so much more performance that Revo hadn't accessed with their mapping. The 1/4mile was then broken by APR's stage 2 software and still stands today due to its mid range grunt. I have always found you can have a good exchange with a technician from Apr and they are really helpful.

BOTTOM LINE: APR if going up to stage 2, CUSTOM If stage 3
COST: £400


INTAKE: FORGE VS ITG VS CUSTOM

There are only really two off the shelf offerings here... FORGE and ITG.
There are a few European offerings but not alot of evidence to rely on. Having seen a dyno comparing the ITG to the FORGE, the ITG is far superior. It's actually the one vw racing use. It's called the maxogen induction kit. I use this myself.
On the ibiza, it takes cold air from a pocket of low pressure behind the headlight.

I modified the kit by getting 2 silicone hoses and 90 degree bend so it took the air from the grill. I had to cut away alot of the plastic around where the original intake took its air to pull the ducting through. This uses the force of the air hitting the grill at high speeds to assist the air getting through the filter. It will be colder too.

Although a custom would be better than stock, you need a decent filter like a MAXOGEN filter and a heat shield because of the heat of this engine is so great. So in this case you might aswell go off the shelf and straight for the ITG MAXOGEN induction kit.

BOTTOM LINE: ITG all the way
COST:£300-350(for carbon limited edition one. available on demand from ITG)


EXHAUST: MILLTEK VS SCORPION VS CUSTOM

For off the shelf both offerings are around the same price, have the same spec pipe and both have a good reputation. The big difference is the location of the catalytic converter. On the MILLTEK it is on the downpipe, on the SCORPION it is after the downpipe underneath the car.This actually makes a huge difference in theory. Your downpipe is where all the gains come forming performance, the rest if the system (cat back) as long as it is of a certain size, then its only worth a couple of horses.
So the SCORPION is the one to go for because they have essentially increased the length of pipe before the cat (downpipe) and decreased the part that makes little difference(cat back).

Custom is another option and if you can find yourself a good local exhaust fabricator, you can have your exhaust done for half the price of the off the shelf offerings. size wise you need to go as big as possible on the downpipe which is 3" but due to the sump at the bend underneath the car, you are forced to go down to 2.5" from there till the end I'd the exhaust. Most exhaust fabricators don't do a 2.75 which is what the SCORPION and MILLTEK are so that's the advantage of the off the shelf ones. That is offset though by the fact you can go up to 3" on the down pipe with the custom.
The beauty with the custom is you can select your silencer so you can have it as loud(no silencer) or as quiet as you want just by telling the fabricator. A 100cell catalytic converter after the downpipe will give you the advantage of the SCORPION too. You will have to extend the lambda probe lead so it has enough length now the cat is further away.

BOTTOM LINE: Custom will be cheaper and better for what you want. If your goal is stage 2 then go 2.5" all the way and you'll find your turbo will have more pick up than 3" to 2.5". If you plan on going further then go 3" downpipe to 2.5" catback.
A less restricted exhaust will help the issues with the engine as it will clear exhausts gasses better


DECAT WARNING.... Tbc

Source: Lucifer's Ultimate Guide 2: Tuning the 1.4TSI - SEAT Cupra.net - SEAT Forum

[The_Hawk]

Has anyone put a catch can into the 118tsi and have some advice/guide pics on the install and/or what parts they used?

[Mk R]

Awesome guide huh. I've not set up a catch can on mine.

[VW Convert]

I stumbled across this thread in another forum (see the source at the bottom) and wanted to share. There is actually a number of good posts over there by this guy that are worth reading:
SEAT Cupra.net - SEAT Forum

Some great reading there, very in depth, the sad conclusion however is that the 1.4 twincharger is a fundamentally flawed design.

Interesting that he writes "1.4TSI engine is actually based on the old 1.4 16v engine from years ago" when describing the issue of fuel injectors extinguishing the flame due to positioning of the spark plugs relative to the injector. I wasn't aware of this and can't help but think how good this engine could have been if it had been designed from scratch rather than being based on an old engine.

Cheers

George

[Greg Roles]

Catch cans on the TSI's are tricky as you have both a pressure and vaccuum PCV system due to the pressure difference across the throttle, hard to plumb in just one catch can to the two systems. I've had a few people try it over the years, and they have chosen one system to run, so they at least halve the gunk. Another option is two cans. Diesles just run vac all the time with a pre turbo inlet, they are always working at WOT throttle wise.

I reckon a bit of thought and some decent ( Provent ) one way valves you could do it. It is indeed very hard to find proper one way PCV valves though.

[Mk R]

It's disappointing they have so many issues but there's so many of them that the parts are pretty cheap. I've certainly poured way more into repairs on a previous Prado D4D and WRX than I have into the 118TSI. If i got another 50,000km out of the current CAVD block I have I wouldn't be fazed dropping another couple of grand to switch in a CTHD centre block and keep it rolling as a second car. It's way too much fun to drive to consider selling for what they fetch these days.