Boost not meeting requested, graph inside

[v4rley]

After visiting R-tech I left no better due to the car not being able to achieve requested boost. The actual is a consistent 4psi below:


The car was smoke tested on the day and a good going over by the team there.
I’m left trying to figure out the issue. Would this appear to be turbo problem?

[pudding]

Only 2 possibilities - 1) the boost is bleeding off, or 2) it's not making any boost.   1) is most likely.  PCV, DV, boost hoses leaking..... the usual checks to perform.

[Dan_FR]

Weak actuator is another - Sure i saw another thread of yours with VCDS graphs in showing 100% N75DC..... So either your turbo is broken, you have a leak, or your actuator isn't doing its job.... As the requests certainly weren't unreasonable for a K03 from memory

[v4rley]

@Pudding It was smoke tested on the day at rtech and also did some smoke test whilst on the dyno so not sure if there is still an unditected leak

@Dan_FR yeah they were my logs.
Brief history of the car I have had it for 5 year, already had a stage one quantum when i got it. Mainly the wife’s car but I occasionally give it a good drive now and again. On this map it was running 95% N75. Maybe to my perral I have had the bcs and intake in for the last two year on the original map and on WOT it would have black smoke when the boost kicked in.
Niki said the actuator wasn’t the sloppiest he had seem but obviously this was only a manual check from under the car with a bar reaching up in. Other suggestions was that the tips on the turbo have melted

I have only just got my head around logging so haven’t got any earlier ones to compare to. I find it strange that the boost seems to follow with a consistent -4psi

[Dan_FR]

Did Niki actually confirm there is an issue? Did he not map it or just upload a base map? Did he give any advice or suggestions?

Turbine tips can be examined by removing the downpipe, compressor side can be examined with a cheap borescope. If you dont have a boost leak, and are running at 100%DC and not making the boost (and airflow - MAF reading?) then it can only be some form of turbo problem. Extra preload on the actuator can help rule that out, so probably worth trying

[v4rley]

Yes he said it was the worst he had ever seen and left with a addition 2hp from the original map.

His first concern was that I had installed DV relocation kit (k04 style) same as here Say that he had never seen it done before. So he suggested I started by putting back to oem (which I have) and still logs the same. He did spend some time looking at various aspects and trying to sort it but obviously limited time available.

He has loaded the 5 map thing and these log are in #5 so haven’t logged or know what the N75 request is on the others.

Ok haven’t logged the MAF will do that on my next logging session, would this have been looked at whilst mapping ?

To add preload I guess that’s adjusting the bolts on the actuator rod is that feasible with it still on the car?

[ROH ECHT]

Assuming the DV and boost plumbing is all good; Test the PCV, check the rear breather tube for cracks as well as fitment to the turbo (also the anti reverse flow valve inside), check the Mass air data (full load 2k rpm to redline...2nd gear is OK), and post the values of 'LTFT group 032 blocks 1 and 2' (done while idling when fully warmed).
Check the N75...one of the three nipples could be cracked or have loose hoses attached.
The WG preload is likely not what's failed...but not one to rule out just yet.

[v4rley]

[v4rley]

Block 032 after above logs were done



Checked the N75 all seem fine with no damage to nipples and still oem clips intact and firm

Dv and pipework appear fine

Rear pcv again doesn’t seem to be crack or any damage

[ROH ECHT]

This all is looking like the wastegate. Likely not sealing when wgdc is near maximum...due to WG not sealing because damaged or there's loose linkage allowing slop in the WG positioning. 

Nothing points towards leaks in the LTFT. It runs a bit rich...below 0.82 actual is a bit rich and LTFT multiplicative also confirms richness at -1.6% additive. Low pressure pump dips below the 4 bar minimum.

It is not common for the WG actuator diaphragm to tear...but the spring inside the actuator may have weakened. You may try adding WG preload, but it is tough doing on a K03 vs a K04...but can be done. Look up vids on how to change WG preload for guidance or I can help with questions. The thing is, is if you do make an adjustment and find it getting better...likely would want to start thinking about removing the turbo and give it a thorough inspection and possibly end up replacing the WG actuator. So, might as well be prepared for a new turbo with actuator included.

[v4rley]

There is a adding preload guide So basically this is what I need to attempt

I did acquire a second hand k03 the other day as it was on my travels as I can have a good look at that in the garage before attempting the one on the car.

The fuelling situation would the be a situation as this is only a base map so hasn’t been fine turned for optimum efficiency?

[Dan_FR]

The drop in the low pressure side coincides with the high pressure side creeping to 140bar - unsure why the car is doing this but certainly is not the issue. Everything else looks good, load, MAF looks bang on too for a K03 etc.

If it were my car, the next thing I would do personally is remove the vacuum pipe to the actuator and take it for a drive, with the laptop on and keeping a VERY close eye on the boost reading. In theory it should drive exactly the same in terms of peak boost and performance, but there's a chance it could not and you could see turbo shattering boost levels at lower rpm

I'd also go with checking the wheels for any damage, melted tips etc. as its fairly easy to do, and if they look OK and the pipe removal yielded no significant change, I'd re-attach it and then add a fair bit of preload to try it out and see how you get on - you can always back it off at a later date if its a little much

19PSI peak with 100% N75DC (based on previous graph/log), without a leak, is definitely a turbo problem. This little turbo could easily peak at over the MAP sensor limit of 1.5Bar by 3k RPM if all were ok

Also, just an FYI - my K03 2+ can hit and maintain the requested boost levels in this map, so they are achievable and are what you should be aiming for

[v4rley]

OK, thanks I truly appreciate that assistance from you both and will do as advised. I’m a long way from rtech and no Indy’s near me so this help it great 

So tonight’s plan is to remove the actuator boost feed and see what is achieved. Would I be ok montering this is polar fsi? Just a bit easier to do whilst driving.

I have just ordered a borescope so will get onto this once it has arrive.

[pudding]

Has the turbo whistle pitch changed recently?   That's how on a previous car I knew something was up with it.  The whistle changed in volume and pitch.

It drove OK though, but when I inspected it, all of the inducer blades on the compressor wheel were chewed to pieces.  Obviously something harder than aluminum made it's way through the intake!  Bye bye 1 x expensive GT3071R turbo    Niki posted a pic on the TFSI group ages ago of the exact same thing on a MK6 R that wouldn't make the usual power........but people love their plant pot on the end of a pipe intakes don't they.

As per Dan, god knows what that HPFP spike is all about (EGT / component protection map kicking in perhaps), but you are running some crazy AFRs.  Mid 11s in places.  Waaaaaaaay to rich for DI.  ~12.8 is where it needs to be, otherwise it defeats the purpose of DI.   Mid 11s is old port injection nonsense because tuners were too afraid to tune for power.  No need for that at all on TFSIs.

Anyway, I'm not convinced it's an actuator problem.  I think the turbo is worn out / damaged personally, but keep us posted!

P.S. What app do you use to make those nice graphs from the VCDS logs?   

[v4rley]

Haven’t really noticed a difference in turbo noise, have tried a few dire things intakes over the years so alway getting different tones anyway, I haven’t experienced any loss in power either.

As mentioned earlier thing is I don’t often drive the car and usually with the family when I do so not often it gets driven hard, maybe this has prolonged the issue turbo life

Yeah I have know idea about fuel trims / afr Niki did say about over fuelling may have cause the turbo to overheat and damaged the fins.

Ah the logs! They are with thanks to @dazza for writing the program to do the graphs, although it took me a while how to figure out how to use it!  guide here