MK5 Golf GTI
All Things Mk5 => Mk5 General Area => Topic started by: MS1 on March 06, 2016, 11:39:54 am
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Hello there.
So I started to notice a couple of flat spots, that have gradually become worse and worse. Took my car out and did some live logging with a mate today and it showed the wastegate function was a maximum of 75%, but mostly 40-50% if that.
Diverter valve or wastegate issue?
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If you're not already on a revision G dv it's worth changing to that anyway.
Then see what your logs say.
Although a dodgy dv usually means a consistent loss of boost over the revs rather than flat spots.
Don't rule out the MAF or N75.
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I've got a revision G ready to go, as I'm booked in with R-Tech on the 23rd.
Had a new N75 valve replaced only a couple of weeks ago as a matter of course.
I'm having a smoke test tomorrow, so will get MAF sensor checked too.
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You'll love the map. Their reputation is well justified!
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I'm buzzing for it mate, they're mapping in a new Loba HPFP too!
Just a little apprehensive as I've been experiencing the odd boost issue of late and it's gotten a whole lot worse these last two or three days. I'm desperate to get it sorted, as I don't want it be turned away from R-Tech, especially as it's a 500 mile plus round trip.
I've had so much work done recently. Cambelt kit, water pump, thermostat. Clutch and dmf. N75 valve. New R8 Coilpacks and NGK Iridium BKR7EIX. New ITG Maxogen G60 CAI. Forge throttle body hose. I'm guessing the problem/leak could be coming from anywhere. Fingers crossed, a smoke test brings something up because I'm getting a little disillusioned having spend £2500 on the old girl and having had nothing but problems since. Prior to than 70,000 trouble free miles, 100% boost all the way haha!
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Fingers crossed for you pal. All I'd advise is don't go to R-Tech unless you're 100% happy you've ironed everything out.
I was due down there last month for a tweak up to Stage 2 after having a full Powervalve fitted. What happened in reality is that the extra torque from the exhaust finally pushed the clutch over the edge. So I've had to cancel R-Tech, and I should be collecting my Helix Organic clutch and new dmf tomorrow! Will get that fitted asap...
And I'm seriously considering a Loba pump myself before I book back in at R-Tech, as I'll then have a clutch that's good for 400lb/ft. Although I know it's 500 notes I should be putting towards a BBK instead!
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Yeah you're absolutely right. I don't want to rock up there if it's going to be a waste of everyone's time. Even though I'm desperate for a stage 3 tune. Thanks for the kind words and good wishes mate. I'm just hoping it's a f*cked DV or split pipe or something.
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I seem to be getting full boost for a second or two, then half boost, then no boost, then three quarters boost. It's just all over the place. Got the car scanned on Delphi this am. No faults, all well apart from the wastegate function being like 40-75% and intermittent. But truth be told, I don't know what that means anyway. It has to be a boost leak, can't be PCV as I have a BSH PCV Kit. Can't be turbo back, or I wouldn't get severe boost loss. So here's to productive smoke tests!
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I might be wrong but I'm sure sporadic wastegate values would point to the N75, although you've got a new one...? Strange.
There are quite a few components that can fail intermittently without giving a fault code. MAF certainly being an obvious one.
One of the downsides to getting loads of parts changed in one go like you have is that it's difficult to narrow down the culprit quickly if things go wrong! Without a code it's just a case of old fashioned process of elimination.
You say Stage 3 by the way, am I right in saying that includes a turbo upgrade?
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I don't mean to scaremonger, but have a read through this old thread from Redrobin, if you've swapped out all the usual suspects
http://www.mk5golfgti.co.uk/forum/index.php/topic,493.msg6524.html#msg6524 (http://www.mk5golfgti.co.uk/forum/index.php/topic,493.msg6524.html#msg6524)
Hopefully it's not as serious and the smoke test will show up a simple fix :happy2:
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I might be wrong but I'm sure sporadic wastegate values would point to the N75, although you've got a new one...? Strange.
There are quite a few components that can fail intermittently without giving a fault code. MAF certainly being an obvious one.
One of the downsides to getting loads of parts changed in one go like you have is that it's difficult to narrow down the culprit quickly if things go wrong! Without a code it's just a case of old fashioned process of elimination.
You say Stage 3 by the way, am I right in saying that includes a turbo upgrade?
Yeah new N75, so I think it's safe to rule that out. Having said that that maybe pipes were poorly connected upon instalment? I've noticed the flat spots since all the work was carried out, so it's entirely feasible I guess. The MAF is a good shout, but I'm hoping it's as simple as a knackered vacuum pipe. I also recently went for the NGK Iridium BKR8EIX plugs, heat range 8, which maybe a possible cause. I've got some OEM Bosch Plats on order to switch over just in case it is that simple. Although I'm not getting a misfire or an EML, so I'm not convinced it's the plugs.
I wasn't aware Stage 3 was a turbo upgrade. I'm certainly not anticipating that. That's just what I was told by a bloke called Ben at R-Tech. You can see my mods in my sig and there ain't nothing else to it. With the whole car polybushed and the track mounts, I just figured another 60/70lbft wouldn't go a miss. I've also had this custom map on for 35,000 miles, so something new was the idea. Everyone rates them, so here's to change ha!
I don't mean to scaremonger, but have a read through this old thread from Redrobin, if you've swapped out all the usual suspects
http://www.mk5golfgti.co.uk/forum/index.php/topic,493.msg6524.html#msg6524 (http://www.mk5golfgti.co.uk/forum/index.php/topic,493.msg6524.html#msg6524)
Hopefully it's not as serious and the smoke test will show up a simple fix :happy2:
I've looked upon page after page after page and I'd be surprised if it was the turbo, but stranger things have happened, so if it is, it is. Let's hope I can get another before the 23rd haha! I would say I do look after the old girl, she's always been given 30-60 seconds to cool down, even after less spirited runs and although she's been pushing 20lbs of boost for 70,000 miles, a lot of that has been mild or off boost driving, or motorway miles. Cheers for the support though buddy!
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This will probably sound really stupid. But I did disconnect the MAF today with the intention of going for a drive and seeing if the issue went away, but after i turned the engine over, if just died, so I promptly put the f*cker back on.
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It won't like the MAF being pulled one bit, unless it's fecked and already substituting it's function with another sensor. As your engine died, it's a good sign the ECU was happy with it's signals.
I would go out for a spin and data log the requested and actual boost pressure measuring blocks. The erratic N75 behaviour sounds like it's struggling to maintain the target boost, whether that's from a boost leak or some other hardware issue, who knows but at least you will get a picture of how far off the boost is. Hugely off means a significant hardware fault which shouldn't be too hard to trace. Ignore any transient peaks as the N75 takes time to react and smooth the boost out.
The N75 actuation isn't usually huge numbers anyway, unless the map calls for a spikey delivery.
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So wheres the datalogs?? Nobody will be able to help without datalogging
N75 will be sporadic, it will never be static as it responds to a load based request from the ECU. Numbers can be quite high, especially at higher RPM as the K03 usually runs flat out on more aggressive maps, not helped by the weak standard actuator
If the boost is up and down like a yo-yo, and I presume the N75 follows suit, have you checked the requested and actual load, and whether the TB is closing etc.? Also checked fuel pressures (low and high sides), fuel trims, lambda etc.
K03 means at most its a stage 2+ map. Have a read of R-Techs website.
The engine should idle and run fine with the MAF unplugged electronically, it should only stall and cut out if you remove the MAF from the intake with the engine still running (having undone the 2 screws) and with the electrical connector still plugged in
Have the issues literally just started in the last few days, or started after changing certain hardware and continued to deteriorate from there?
If time is that much of an issue, don't waste it and get it booked in with a local specialist, or get someone local to take a look, run some VCDS logs etc.
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So wheres the datalogs?? Nobody will be able to help without datalogging
N75 will be sporadic, it will never be static as it responds to a load based request from the ECU. Numbers can be quite high, especially at higher RPM as the K03 usually runs flat out on more aggressive maps, not helped by the weak standard actuator
If the boost is up and down like a yo-yo, and I presume the N75 follows suit, have you checked the requested and actual load, and whether the TB is closing etc.? Also checked fuel pressures (low and high sides), fuel trims, lambda etc.
K03 means at most its a stage 2+ map. Have a read of R-Techs website.
The engine should idle and run fine with the MAF unplugged electronically, it should only stall and cut out if you remove the MAF from the intake with the engine still running (having undone the 2 screws) and with the electrical connector still plugged in
Have the issues literally just started in the last few days, or started after changing certain hardware and continued to deteriorate from there?
If time is that much of an issue, don't waste it and get it booked in with a local specialist, or get someone local to take a look, run some VCDS logs etc.
It won't like the MAF being pulled one bit, unless it's fecked and already substituting it's function with another sensor. As your engine died, it's a good sign the ECU was happy with it's signals.
I would go out for a spin and data log the requested and actual boost pressure measuring blocks. The erratic N75 behaviour sounds like it's struggling to maintain the target boost, whether that's from a boost leak or some other hardware issue, who knows but at least you will get a picture of how far off the boost is. Hugely off means a significant hardware fault which shouldn't be too hard to trace. Ignore any transient peaks as the N75 takes time to react and smooth the boost out.
The N75 actuation isn't usually huge numbers anyway, unless the map calls for a spikey delivery.
Okay so the logging was done spur of the moment. Nothing to show you guys. Sorry.
Yes I removed the whole MAF from the intake. Then turned ignition on. Car started and died right away. No drama there.
The boost isn't hugely off, so I figure it's not a big hardware issue, but it is off. So potentially leak somewhere or N75 valve is what I've been told.
Do you recommend upgrading the actuator?
The map I have has no torque spikes, it's very linear as previous plots have shown.
Throttle body function is perfect, fuel trims good, lambda all good. The issues have started in the last week or so, but gradually become worse. The boost issue is also intermittent. Yesterday it was all over the place, today it seemed perfect.
I read R-Tech website, yes it's Stage 2+, I don't really go much on what's what or what x and y is etc. I just know how I want the car to feel. I've been told what is possible with the set up I have and tbh being told 'you could achieve 300bhp/350lbft' means very little to me, I just want the best map and best delivery I can get from a map and R-Tech were top of the pile.
Thanks for your time and help lads!
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Where are you based mate? You could save a lot of time by getting it into a specialist for them to have a proper look.
There's plenty of knowledge on here but it can easily turn into a guessing game.
Hope you get it sorted asap anyway mate.
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I'm in South Devon mate. It's going in Wednesday for a smoke test and to have the Forge DV removed and Revision G installed as a replacement. I'm always trying to self diagnose and have been using the forums for years, more golfgtiforum than anything else and as you say it's a nightmare because it turns into a guessing game. But it's only people trying to help, which I really appreciate. I'm sure it's something simple. N75, DV, torn vacuum pipe etc.
Thanks bud
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Would love to be able to recommend a good specialist near you but I'm miles away so I'm clueless there! Fingers crossed they can find the issue.
As it happens, Niki always recommends the rev G, especially over any Forge valve. In fact I've heard that he won't map a car if it has one!
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I'm confident in the garage I use, so I'm sure they'll fix it. You're absolutely right, R-Tech won't map unless it G Revision DV. I emailed them with my issues and the only thing they replied with was, 'Change that Forge DV!'. So let's hope it is that.
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I know this is an old thread but I have a 2.0 TFSI Audi A4 with GIAC Stage 3 K04 tune Autotech HPFP and Golf R injectors.
Attaching the log after adjustment.
After adjustment (1.5 nut turn looser) It no longer goes limp after reducing the spring press on the wastegate which is great but I do feel like I hear a leak and it struggles to maintain spec sometimes.
https://1drv.ms/x/s!Akrf9oowYt38gtw62482p2YbSuhW2A?e=vYzbIE