Easily the most popular article I wrote was the Common issues, tips and tricks for the 2.0t FSI BPY engine. People seemed to find it very useful so I figured I would make another for this engine too. Though I have to admit this EA888 Gen3 engine is significantly more reliable and has less quirks. That doesnt mean it is free from problems so lets go over them. This article will be a little sparse at first but over time I will add more items to it as problems are discovered with this engine.
Engine valve buildup:
Just like any direct inject engine that doesn’t have multi port injection or something similar to clean it, this engine gets carbon buildup over time. Because of the way the fuel injection works the gunk can buildup overtime on the valves by oil and junk flowing through the PCV system to the valves. to the left is a picture of what valves can look like overtime. Europe did get MPI (multi port injection) on the EA888 Gen 3 engine but sadly this feature did not make it over to the US.
Loss in performance is a sign that this might be happening. But that is also a very vague sign that could be the result of a lot of things.
If you already have buildup the best way to resolve it is take it apart and clean it. This is a very time-consuming task or expensive if you have a shop do it. You could try using a cleaning solution like Seafoam or BG Induction Cleaning that doesn’t require taking everything apart.
Another option is to install a catch can. This will catch the foreign contaminates in the PCV system before they get to the valves. You will need to empty the catch can every so often. A good time is when you do your oil changes. Another option is the “Italian tuneup” which is running your engine at higher RPM’s occasionally to burn off any buildup you engine has. If you are a spirited driver this may not be necessary but for those conservative/commuters this can help.
The best thing you can do to prevent buildup is use higher end gas and try not to do short drives. The cheap gas has less cleaning additives that don’t help this situation and shorter drives dont allow the engine to heat up enough to burn off anything that might build up on the values. The old Italian tuneup is something other recommend for that reason.
Here is a discussion on this issue: http://forums.vwvortex.com/showthread.php?8009609-Carbon-Buildup-on-MK7-s&p=97730409&viewfull=1#post97730409
First before you get too scared this issue is not common, I almost didnt even add this due to how rare it is. The GTI/R people have reported some turbo failure. Some versions of the IHI IS20/IS38 turbo that these engines use had some problems. This is a great thread discussing the issue: http://www.golfmk7.com/forums/showthread.php?t=5276 Its not relevant if the car has modifications, stock ones failed too. I would suggest that before adding software to your car you hit 10k miles first to make sure your turbo is reliable. Typically this was an issue with early cars like 2015 models. Newer models dont have as many reports of this issue.
Typically the failures are due to bearings failing, the turbine shaft isnt balanced well enough and becomes wobbly and then the turbine fins get shredded. Some people when upgrading their turbo or replacing it are sending it off to a shop the specializes in turbos to get the shafts balanced before installing it.
If you are interested in finding the model number of your turbo, its located on the back side of the engine. Follow the intake to the turbo, just past that to the back side is a plaque that has your model number. Here is a youtube video showing it. https://www.youtube.com/watch?v=Ntwo5eKQYls It might be a good idea to have a telescoping mirror with a light on it to take a picture of it in a tight area. I myself have a 06K-145-722-G and the build date on my GTI is 07/15, so far mine has been great.
Update: Since the Rev G the turbos have been more reliable (less reports of issues on the forums) and the current version as of late 2016 is L. So it seems it was mostly and early on issue.
Oil filter housing:
The oil filter housing is plastic and it is very easy to crack by over-tightening or not taking it off correctly. As with the previous generations of these engines a metal version of the housing has come on the market by a third-party and although this sounds like a nice solution it only causes a higher chance of stripping the plastic threads where it screws onto. Its much better to have an issues with the housing than where it connects to the engine block
Suction Pump Recall:
On some 2015-2016 GTI/Golf/A3 models the Suction Pump would fail causing fuel to back out of the tank or the car not to start. If you have ever had this happen the dealer should fix it for you. You can read more here: https://www.carworklog.com/2016/12/30/recall-suction-pump-replaced-under-warranty/
Thermostat housing leak:
The thermostat housing can leak. Replacing it with the latest version is a good idea if you find your coolant is low or you smell coolant a often after drives. Please also note the coolant reservoir is under pressure and when you remove the cap the level of coolant may rise. So remove the cap on the tank when checking its level. Its also important to use the OEM coolant and follow the instruction on the container when filling. G13 coolant is what the OEM uses, it should be a pink colored liquid. Dealers will do a pressure test to see if it passes, some leaking housing still pass their pressure test.
As with most VW forced induction engines the water pumps are a weaker point. They are not super common and dont break as often as older engine but still do occasionally. I have not seen a metal one available yet like older platforms, probably because the issue isn’t as common.
PCV system and oil:
Although the PCV systems doesn’t break causing loss of pressure like previous generations it does have a new issue. When the car has been under prolonged WOT accompanied by aggressive braking oil can be sucked into the intake manifold causing plumes of smoke.
What happens is the small check valve drain, normally used for emptying blowby not large amounts of oil into the pan, gets overwhelmed and oil gathers in the PCV. This causes pressure to build eventually causing extra oil to not go into the pan like it should but into the intake manifold. If this happens enough you will have build up problems.
That being said this issue is only cause under extreme conditions. Unless you are driving super aggressively on lets say a track or auto cross this issue likely wont come up for you. Solution right now are catch cans like the Spullen one that replace the front PCV system to handle the extra oil. I personally don’t want a catch can and am waiting for a more simple PCV fix. I also have only seen this issue happen twice on my car and have a feel for the conditions when it happens and will try to avoid it until a proper fix is released either by VW or third party. Likely third party in this case like the MK5 PCV fix.