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Discussion Starter · #21 ·
In not an expert but

1. what modifications (even replacement parts) do you have?

2. And what issues stopped the mapping?

3 what logs have you created?

4. What is the actuator only pressure (electronically disconnect the n75 and it'll bypass the valve and you'll get 0% wgdc as David said above 6(ish)psi


Incidentally, bypassing the N75 with a parallel MBC / EBC won't help you diagnose why it's overboostig, it will just stop it going over whatever you set.

I removed one of my springs in my actuator as the default was 15psi, which worked fine if I was booting it in the right gear, but when the maximum flow was met the boost hit the 35psi pin - I was also getting similar issues if⁷⁷ I floored it in a high gear. Eg if I put my foot flat in 5th at 1500rpm it couldn't do anything with the air, so just built up pressure

I sorted most of this out, but was just too highly strung. All my boost issues were caused by a non standard actuator, which throws out the PID mapping tables.... so you need to limit the wastegate duty.
Hi @StuartDB

I'm no expert either :)

Mods....
  1. Hybrid K04 by Turbo Dynamics
  2. 3inch Miltek Exhaust with a decat
  3. Uprated coils (I think someone said they are from an R8)
  4. Forge DV with cold side relocate and Forge ICPV
  5. 80mm TIP
  6. Sytec 275l/hr fuel pump (a DW copy)
  7. Bosch 610cc injectors
  8. Catch can
Plus a bunch of other stuff that is probably unrelated... Forge baffled sump, Creation FMIC, Innovate Motorsport oil temp, oil pressure and boost gauges, suspension and brake mods,

Tuned (mostly) by Badger5. The issue was that they said they saw oil smoke from behind the engine. where the turbo is located. I have been unable to locate a leak. I thought it might be oil burning off where I'd had all the lines disconnected but then I managed to make a small puff of smoke come from there also when we held the revs at 3-4k for about a minute.

I logged the output from the boost gauge when I was doing some test running. This was before it started bellowing the smoke. I've attached the traces. Bear in mind here that I was trying to moderate the boost with my right foot to stop it getting to 1.9bar but I definitely saw 1.9 and 1.7bar on other occasions. The one where I have 1.15bar peak seems better but again I was not really flooring it for a sustained period because I was nervous of too much over boost breaking something serious. Something to note here is that the DV and FMIPCV were not installed when Badger did the map, but unless I'm being daft I can't see how they would be causing this. Bill said he mapped only to 1.2bar which was 'shit' in his words but then he saw that smoke.

As you can see in one of the traces I actually had the N75 in line but the electrical connector disconnected and I made it to 1.15bar even moderating the throttle a little.

Appreciate the brain power on this guys.
 

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Hmmm... so what psi do you get unplugging the N75, so running on actuator only?

Surely the hybrid won't have a stock 6psi actuator? My updated actuator I got when I put a turbo rebuilds Hybrid CHRA in was a 1 bar actuator, it was a nightmare I needed to limit the max WGDC to about 45%. Hence moving to 10psi until MOT'd.

If you have all that kit, do you have forged rods?
Does your catch can fill up?

My car went well over 35psi, when I was getting overboost, it wasn't throwing up an error, but had literally nowhere to go..

The charts i have seen from people who go to B5, they tend to have a clean 24-25 psi boost, as soon as it goes over the map sensor reading, it doesn't really know what it is, and just tries to form accordingly.

I assume your miltek includes a downpipe?

Is the boost okay if you select a sympathetic gear?

I am uncomfortable asking you to floor a car with stock rods....

Eg roll in 3rd gear at 1500 rpm..... start logging... for flat... at 6500.. change gear and stop logging. It probably is okay
 

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Look... you have a highly modified turbo charged car... this generation of VAG cars are some of the easiest cars modify, scan, map and repair.

I'm pretty sure most of the previous advice was based on a stock(ish) setup..

My advice would be...
- if you have a laptop get a kkl lead and get visual me7logger and ecuplot installed... you cannot go running to a tuner everytime you think something is wrong.
if you log you car you'll know whether or not its actually overboosting... within reason in any case.. the ECU cannot report more than 1.55bar boost, unless you fit a 4bar map sensor, but that requires other changes...

Once you have a real log of the car, you might see some extra faults...

Did you fit these parts yourself? Or have you bought someone else's project?
 

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Discussion Starter · #24 ·
so what psi do you get unplugging the N75, so running on actuator only? - will test this weekend after the car is back together again.

Actuator is a new one and I've just checked with TD - 0.8bar which is only a shade over the 10psi that you are running.

No forged rods yet. Thats next on the list. I told Badger though so they could keep my torque down.

Catch can has not filled up but I have not don't lots of miles, maybe only about 50 in testing.

Over 35psi! ouch... do you have rods done already? When you say it has nowhere to go what do you mean?

Yes Miltek downpipe also.

Will try your rolling test this weekend also.

Will also install those apps this weekend and run them. Good shout thank you :)

AT this point I just want to find the smoking gun so I know what it is.... even if it does necessitate lots more work! lol

Some of the work was done before me, some by me but in terms of that list, only the exhaust and can where done before me. It had a Revo stage 2 map before B5 also and Bill said the boost was turned up massive which, coupled with the fact that the previous owner had no DV, likely contributed to the turbo letting go.
 

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Discussion Starter · #25 ·
@StuartDB can you point me in the direction of those bits of software? Struggling to find a good download version, only the raw code on github.
 

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Over 35psi! ouch... do you have rods done already? When you say it has nowhere to go what do you mean?
Yeah, I fitted PEC rifle drilled forged rods a couple of years ago..

ref "Nowhere to go"

it's all about the flow :D the air needs to go to somewhere if it is not being combusted, it is building up in the charge circuit and will eventually either exit through the DV (emergency exit), or a hose blown off etc

so... I could do test runs all day long in 3rd gear from 1700rpm to 6500rpm - that would be 30psi - (my target with WMI) and controllable with no ignition retard (knocking) but when it hit ~265g/s - it stopped increasing the g/s and boost built up instead until I changed gear, or dropped the throttle (open DV on vacuum)

but if I floored in in 5th the boost would be building up for longer and hit the 35psi pin if not careful.... it is fine for me to drive as I know how it behaves, but the map and / or hardware needs changing to be more stable.

I will find VisualMe7Logger but you'll need an "ecu" file to create the interface profile. I have them as I read / write the ecu flash, but I am not sure if it needs to be the exact ecu profile or one like it eg a BAM or APX one.
 

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visual me7logger

I had problems too, looking for the actual executable programs - I think it was related to not being a member of nefariousmotorsports - you want to look for ecuplot too as it creates charts based on the out log files, the bit of investigation overhead first - will pay dividends to manage your car.
 

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Discussion Starter · #28 ·
Hey all (especially @davebowk and @StuartDB )

Here's a little video of todays test after we rebuilt and connected everything.


As you can see. It's not condensation. It was smoking out my whole street when we gave it some revs.

Did a head gasket test with the blue fluid. The Sealey kit I got is a bit weird but we did it twice to the instructions and the liquid stayed blue even after we had been running the engine for 10 minutes.

Comp test was 102, 118, 115, 120psi over an average of 3 tests which seems a little low but I have another TT here with the BAM engine thats done 141000 miles so I did a comp test on that and the results were almost identical with my tester and the air pressure set exactly the same.

Leak down is still suggesting busted rings because it suggests 90% loss on the gauge on every cylinder into the crank case. However, I am not confident in this because it idles and runs nicely and at that much loss I would expect it to hardly idle at all. I've not driven it far enough to know if if I am consuming oil.

VCDS scanI don't think shows anything useful. A bunch of codes but I had a flat battery before and they all look likely linked to that. I have saved them and cleared for now to see if they come back.
 

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Discussion Starter · #29 ·
Also here are some scope pictures from my cylinders and the hot side of my turbo....

Tableware Automotive lighting Automotive tire Dishware Kitchen utensil

Automotive tire Automotive lighting Cookware and bakeware Tableware Helmet

Automotive tire Automotive lighting Tableware Rim Astronomical object

Automotive lighting Automotive tire Rim Cookware and bakeware Gas

Automotive lighting Automotive tire Circle Tints and shades Rim

Automotive tire Automotive lighting Dishware Cookware and bakeware Rim

Automotive tire Fluid Tire Water Bumper

Liquid Water Fluid Moisture Electric blue

Automotive tire Water Automotive lighting Liquid Automotive exterior
 

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Discussion Starter · #30 ·
Also adding to this I was looking again at my PCV setup. I have the stock setup deleted and a much simpler configuration. We go from the crank case breather up to a T at the rocker cover breather and then from that T into a catch can (I checked its on the IN side) and then from the OUT side to the TIP.

The can is not filling up but then again I have not run it enough to see that I don't think.

Reason for looking here is because I was thinking that pressure building in the crank case might push oil into the cylinder past the rings but I have disconnected the T from the can and I still get the smoke from the exhaust and a small amount of oily smoky vapour from the disconnected T which is to be expected I suppose.
 

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I would say that's the turbo seals shot, pumping oil into the hot side. Check your oil return is not kinked as any restriction in the return will cause oil to be forced past the turbo seals.

Last year i pressure tested my charge pipe circuit which also pressurised the crank case and in doing so i forced oil through the seal into the hot side and it was like in your video for a couple of miles.
 

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Discussion Starter · #32 ·
I would say that's the turbo seals shot, pumping oil into the hot side. Check your oil return is not kinked as any restriction in the return will cause oil to be forced past the turbo seals.

Last year i pressure tested my charge pipe circuit which also pressurised the crank case and in doing so i forced oil through the seal into the hot side and it was like in your video for a couple of miles.
Thanks Dave. Just to make sure we’re talking about the same thing, when you say hot side you mean into the intake … so the turbo is leaking oil to the intake side of the engine and thus it would be all in my intercooler and pipe work?

Reason I say that is that’s the very reason that the turbo was rebuilt and how I started on this path. Of course it could be the 1 in 1000 that wasn’t rebuilt well but seems unlikely?


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No, leaking oil into the hotside and into the exhaust. The smoke is white from the oil being heated and not burnt.
When i pressure tested mine the hotside was cracked so it forced oil into the hotside and down the down pipe but also got through the crack and all over the drive.

A blocked or restricted oil drain to the sump will also cause this.
Have you got the standard oil drain pipe or have you used an after market one with AN fittings
 

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Discussion Starter · #34 ·
No, leaking oil into the hotside and into the exhaust. The smoke is white from the oil being heated and not burnt.
When i pressure tested mine the hotside was cracked so it forced oil into the hotside and down the down pipe but also got through the crack and all over the drive.

A blocked or restricted oil drain to the sump will also cause this.
Have you got the standard oil drain pipe or have you used an after market one with AN fittings
Ok so that was my original thought but then I was told the smoke looks like coolant.

I have standards oil drain and pickup.


HOWEVER I have just scoped the cylinders and found a little puddle of oil in cylinder 4. Saw it on the scope, used a swab to sample it, definitely oil. So that can’t be turbo exhaust side.


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Turbo is bad then, oil could be pissing past both seals into hotside and cold side.
Your oil return could also be blocked
I fitted a new hotside last year from turbo rebuilds and has been fine.
 

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Discussion Starter · #36 ·
Turbo is bad then, oil could be pissing past both seals into hotside and cold side.
Your oil return could also be blocked
I fitted a new hotside last year from turbo rebuilds and has been fine.
Small amounts of oil in the intake pipe work but not lots. Not enough to see a small puddle on the piston.

Previously I could almost pour it out and had to spend ages cleaning out all the pipe work and intercooler. That was before the turbo was rebuilt. At that point I had black smoke under load so maybe fuel and oil issues. I suppose the black smoke could have been masking this but it looks different. Does that make sense?


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All i can say from your video is that it looks like oil going into the hot side and being heated not burnt. Can be caused by turbo seals gone or a restriction in the oil drain to the sump (the oil doesn't drain and so the oil being pumped in is forced past the seal as it has nowhere to drain to. Until these are checked, it's just guess work.
 

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Oil on top the piston, valve stem oil seal or broken ring ? either way the head needs to come off.
 

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I would agree with David..

White smoke Is oil leaking past the turbo (turbine side) seals and coming out the exhaust.
If oil is combusted it comes out blue (eg rings or pcv etc)
If black smoke comes out the exhaust pipes that's unburnt fuel.

Unless you're losing loads of coolant then that's the headgasket but it'll be running pretty bad to get that amount of smoke and usually smells sweet..

Hmmm... I just read you said there's a puddle of oil on a piston..
 

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Discussion Starter · #40 ·
Yes indeed, that was one of my previous theories and it totally makes sense given that very white cloud like smoke and the clear head gasket test.

But now the oil in the cylinder says otherwise. We scoped that about 30 minutes after stopping the car and it seemed to be running ok apart from the smoke. We subsequently scoped the other cylinders and all are the same. A little puddle of liquid. I didn't swab the others but I think its a safe bet that they are all oil.

Yesterday we moved it from the garage because I have other things to do, and I want time to think. When we did, it was most definitely oily smoke (as you would expect) and its started to idle and run a bit lumpy for the first time.

So I'm back to thinking either rings or severely ruined valve seals. Given the short time period between stopping and seeing the oil, I'm leaning towards it not being valve seals. Add in the leak down test (which may have been right all along) then I think I am going to go for rings unless someone can give me any other counter arguments.

It's just a bit of a ball ache because the 'while I'm in there' parts will all add up.
 
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