All Things Mk5 > Mk5 General Area
BOOST issues. Any advice gratefully received.
MS1:
--- Quote from: AJP on March 06, 2016, 03:41:15 pm ---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?
--- End quote ---
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!
--- Quote from: fab5freddy on March 06, 2016, 07:01:49 pm ---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
Hopefully it's not as serious and the smoke test will show up a simple fix :happy2:
--- End quote ---
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!
MS1:
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.
pudding:
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.
Dan_FR:
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.
MS1:
--- Quote from: Dan_FR on March 07, 2016, 01:10:41 pm ---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.
--- End quote ---
--- Quote from: Pudding on March 07, 2016, 12:36:53 pm ---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.
--- End quote ---
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!
Navigation
[0] Message Index
[#] Next page
[*] Previous page
Go to full version