The great big MK6 Golf 118TSI tuning thread

[Mk R]

Your 2012 will have the newer revision injectors that i now have, so you may run into the same problems with misfires at 4k under full load. May not though - like everything it's hit and miss. In Greece where this engine is tuned a lot i have heard they have had nothing but problems with the APR maps.

I'm in the process of fitting forged pistons and have stripped the engine down. My intake ports/valves at 55k miles are coked up to hell - so it may have been a contributing factor to the misfires...but i do believe the APR map in its current form has issues - lack of boost control for most of the rev range under full load, and i think its borderline on misfiring at maximum torque around 4k rpm due to running too rich.

I've never had that problem and regularly record up to 23 psi on a 2011 CAVD block. From memory the DSG can only handle up to 290 nM so that may explain Guy's lower numbers if that is correct.

He's a really knowledgable and straight up dude, I'd be very tempted to go with his map. He seems to be very conservative with his claims and i doubt he'd offer something that wasn't at least as good as what he sold before.

As far as the intake valves, the ones on the replacement block i installed were 20,000km in and totally covered in tar like black deposits. That was with a stock VW map.

One thing i did notice that the N75 and N249 valves needed replacement after the map. It really refreshed the performance.

EDIT: I know that petrol direct injection engines of all makes get this problem to varying degrees. Really looking forward to that writeup!

[Ryan_R]

blower I'm also fighting misfire issues now on my MY10. Has only happened in recent months, and left unchecked causes engine mounts to fail. Interesting that coil packs did nothing to help you as many others have claimed success there. Although that's somewhat understandable having seen all that crud which I suspect many of us also have.

[rygreen93]

I assume there is no way to control the build-up of "gunk" within the engine? And a full rebuild every 120000km isn't really an option when its your daily driver.

I spoke to Harding Performance again. He basically told me that he has been very conservative in his calculations and with this tune they have the option of doing multiple revisions with the software engineer to perfect the power distribution and torque to give the best possible driveability. I will also be getting a before and after chart so I guess that is what is most important.

[Ryan_R]

Closest thing to managing gunk is installing (and periodically emptying) an oil catch can.
Perhaps occasional use of fuel additives may help - of course won't do much for pre-existing issues).

Given all the marketing behind 98-RON fuels "cleaning your engine" I wonder if we can get feedback from Shell/BP



See also
https://www.youtube.com/watch?v=WQN-0zvZNbY

[Rawcpoppa]

I'm on 113k km using RON 95 here and the car works fine. Stage 1 remap from a company called protune. Not sure how to keep the gunk off but I do WOT a lot here. Maybe that's why no hiccups at this mileage ?

[Ryan_R]

Maybe, although it's hard to imagine too many APR customers driving Miss Daisy

[rygreen93]

I don't think many people who go on forums drive "Miss Daisy". I honestly think that at the same time we flog our cars but we also maintain them and service them a hell of a lot better than people who couldn't care less about what oil went in and when.

[Mk R]

Yeah, I agree. Not too many people would maintain a 5,000km service interval with compression test each time and an exclusive diet of gluten free V-Power.

[Greg Roles]

Fuel additives, special fuel etc have zero effect on upper intake / intake valve stem gunk, as fuel is added directly to the cylinder. Seafoam helps reduce the gunk that eventually builds up on the intake valves like this. Once baked onto a hot intake valve, like the poster shows, you have to physically remove it. V-power etc do not get into your intake on direct injection cars, unless they have some pre injectors often to combat this exact problem.

Catch cans from new, or regular seafoam / upper intake cleaner is the only option, apart from pretending it's not there.

[blower]

I've been lapping the valves in all afternoon....the seats were pretty pitted, a couple of the exhaust valve seats had a hell of a lot of tiny pits. Thankfully none of the valves had any severe deep pitting, but its common on the 1.4 TSI to have pitting on the exhaust side...although i had plenty on the intake too. This no doubt meant some of the valves were not fully sealing.

Ideally this really needed the valve seats recut, but i don't have the time to send the head away for reworking - nor the money!, to damn expensive to get 16 valve seats recut. The valves themselves were fine, although a few of the exhaust valves had some noticeable pitting.

One of the bad exhaust valve seats (this is after it was cleaned with a brass wire wheel on a dremel)



Then after some time hand lapping with valve grinding grit and a wooden lapping tool (hate that thing):



As you can see, still some pitting left - hand lapping was not enough to get rid of all of it - at the rate i was going it it was over an hour per valve of work. So it was time for the drill, drill bit and vacuum hose on end of the valve stem.

Again ideally this should have been radially cut but this is a good enough job, you have to be careful when using a drill to lap, the small section of rubber vacuum hose doing double duty to hold the valve and keep wobble along with any off centre angle out of the valve as it rotates so its face is always flat to the seat when grinding:



All cleaned up, no pitting, good centered finish with plenty of upper angle left on the seat.