APR stage 2 Golf GTI Surging/Pulsing Issues

[adammk6gti]

I wouldn't put a traditional metal hose clamp on the carbon intake pipe as you will likely crack the carbon fiber. Given you have a catch can connected there and not the OEM PCV hose, the 2x o-rings would/should do a pretty good job of sealing that connection up (providing they are a snug fit). If still leaking, go get yourself some black RTV sealant from Supercheap etc and that will fix it for good.

Now you mention that your mechanic recently serviced the car - did this surging issue exist before the service or did it only appear after the service? I wonder if the engine is starving itself of fuel and this is why its dying off momentarily? The HPFP's on the TSI engine are pretty good but they do fail from time to time. Another thing to check would be the fuel filter - has this been replaced and if so, has the correct unit been used.

The service was done when the clutch went in (5000km ago) so that was still stage 1 and once the clutch was worn in properly I had the stage 2 tune done (probably 3000km ago). The surging issue came about once the new tune was introduced, however I feel like it has gotten progressively worse since the care was first tuned, OR I've noticed it more lately because the exhaust sound and power change from stage 1 is less new to me. Its been doing it for a while just have been off work before and over Christmas so didn't book it in or buy parts cause the $$ was an issue.

Fuel filter wasn't done at last service(85K), however couldn't see anywhere in service history book when/if the FF was done. I picked this car up second hand at 75K so haven't personally supervised the servicing of the cars life. How frequent are the FF change intervals on the 2.0TSI?

[Lucas_R]

Fuel filter should be done every 4yrs OR 60,000km - whichever occurs first. So it "should" have been replaced before you bought the car but you wont know for sure unless its noted on service paperwork. Fuel filters are around $50 so not a huge expense and located just in front of the drivers side rear wheel so easy enough to change yourself if you are handy.

Can you take it back to your mechanic to have the issue diagnosed? With some luck the car will have stored some info relating to the problem in the ECU which you can retrieve with a scan to help trouble shooting. Does the check engine light come on when the car is surging?

[adammk6gti]

Fuel filter should be done every 4yrs OR 60,000km - whichever occurs first. So it "should" have been replaced before you bought the car but you wont know for sure unless its noted on service paperwork. Fuel filters are around $50 so not a huge expense and located just in front of the drivers side rear wheel so easy enough to change yourself if you are handy.

Can you take it back to your mechanic to have the issue diagnosed? With some luck the car will have stored some info relating to the problem in the ECU which you can retrieve with a scan to help trouble shooting. Does the check engine light come on when the car is surging?

No Cel at all which i imagine would indicate misfires but its not a irregular pattern when its happening its almost harmonic at a constant frequency surging. I Called VW and got a fuel filter for 80 bucks i can pick up this afternoon. Ill chuck it in after work and see if that makes any difference. Booked in at Eurotune Monday to see if their knowledge can help diagnose it, bit more pricey then my guy but thought they might know a few tricks seeing as they churn through these VWs. Ill post results of the Fuel Filter swap.

-Adam

[adammk6gti]

Fuel filter replaced this afternoon with no difference. Wubwubwub still happening. I'm unsure if it's hardware related or tune related, switching back to stock mode it's pulling nice and smooth. No issues, however significantly less power obviously. If I go to euro tune Monday with this issue, they could flash test pipe file and see if the stage 1 tune still does it then I can go to Apr with the logs. I'll see if over the weekend anyone else has ideas or experienced this and posts here if not shop Monday it is.

[Reedy]

Try putting your stock intake back on. My Bluefin caused issues with the APR intake. Stock intake fixed it.


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[adammk6gti]

Don't have it unfortunatly when I bought the car it wasn't in existence so I can't swap it out.

[Lucas_R]

Sorry to hear the fuel filter had no effect, although at least now that's something you can tick off the list.

Get the place that tuned it to do a scan and a once-over to see if they can pin point the issue.

[adammk6gti]

So just heard back from Eurotune, apparently the N75 valve on the turbo needs replacing and there's a fair bit of carbon buildup on the back of the intake valves and need a nut blast. I've opted for the N75 valve to be done first and see if that makes any difference before i go the nut blast as its only done 90k on the car and had a catch can on for most of its life.

[Reedy]

Nice mate, I completely forgot about that valve. Good work. As long as they tested through VCDs and are not guessing either?There will always be carbon build up on the valves, don't bother. Sold my GTI with 185000klms with no carbon build up issues and no catch can.


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[adammk6gti]

Nice mate, I completely forgot about that valve. Good work. As long as they tested through VCDs and are not guessing either?There will always be carbon build up on the valves, don't bother. Sold my GTI with 185000klms with no carbon build up issues and no catch can.


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Yeah they would have done it with VCDs to see actuation of the valve pwm vs ideal. That's what i was thinking, got on the phone to my mechanic and said probably opt out of the clean for the time being and see if the N75 fixes the issues. If not I'll do the clean next week.