Boost Creep on Audi S3 8l. Is K04-023 original?

[Shaun220]

Hi Guys.

I am new to this forum and hoping someome on here will be able to assist me.I have an S3 8l with a bad boost creep issue. Thought the car maybe had a wastegate port size issue. I have attached the turbo pictures, anyone can confirm if this is an original borg warner turbo.the tag is worn out so can see the blue but can see the part number and serial number.

 

[Shaun220]

More info. Initally thought it was overboost so have changed actuator, n75 valve, map sensor and all vacuum piping to DV and from N75 to wastegate but the same issue remains.
I have electronically disconnected the n75 valve and the car boost to 0.5bar but increases as the RPM climbs. Same results with a direct vacuum line from the charge pipe to the wastegate.

I have done logs previously on Vagcom and requested boost is 0.9bar on WOT but the actuals are 1.4 bar.

The car has been flashed to factory S3 map as well previously.

Not sure what else could be causing the boost creep besides the turbo the last item that has not been replaced.

More pictures of the turbo attached.

Any help will be appreciated.

Thanks in advance.

 

[<tuffty/>]

Looks like a genuine turbo from the pics... no pics of the actuator though?

<tuffty/>

 

[Shaun220]

Looks like a genuine turbo from the pics... no pics of the actuator though?

<tuffty/>

Yeah sorry I removed the actuator off the turbo. Please view actuator pictures.

If the bad boost creep is not the turbo, guess Im at a loss at what causing the issue.

 

[Shaun220]

I have been chatting to some people as I am out of ideas on whats causing the bad boost creep on my S3 8l.

I have heard something that no one mentioned before, if you have a larger 3" downpipe, it can cause boost creep on a K04-023 original borg warner turbo.

I have a brand new original borg warner turbo I picked up today that I dont want to port the wastegate on a brand new turbo if its of no help.

Anyone heard of this before or has any idea if this is true.

Thanks guys

 

[hydro s3]

Not saying the people you spoke to are wrong but when I got my 3" downpipe on I was on the original turbo and I didn't have any boost creep.
That is the only experience I have on this.
Maybe I was lucky but just putting it out there.

 

[Shaun220]

Not saying the people you spoke to are wrong but when I got my 3" downpipe on I was on the original turbo and I didn't have any boost creep.
That is the only experience I have on this.
Maybe I was lucky but just putting it out there.

Thanks bud. I am not sure of the authenticity of the guy either. At first it did not make sense to me either, so thought maybe someone else experienced it before.

I bought a new borg warner oem turbo with actuator. Once my gaskets arrive from Audi, will fit it on and hopefully fix my boost creep issue and the total overboost problem finally.

 

[hydro s3]

Hope you get it sorted soon mate

 

[Shaun220]

Hope you get it sorted soon mate

Thanks. Will let yourl know if the replacement fixes my issues.

 

[Garrett 69]

I worked for Borg Warner for about 18 months when I lived up North. I built their test beds. I seem to remember a common issue with port undersizing. To avoid remanufacturing, they altered the test results on the computer.

When I come to replace my turbo, it won't be a Borg Warner item.

 

[Shaun220]

I worked for Borg Warner for about 18 months when I lived up North. I built their test beds. I seem to remember a common issue with port undersizing. To avoid remanufacturing, they altered the test results on the computer.

When I come to replace my turbo, it won't be a Borg Warner item.

Whats the chances that my brand new original Borg warner K04-023 turbo having a boost creep issue also?

Porting a brand new turbo will void the warranty. Not sure if it is worth it though.

Just dont want to do all the work to fit the new turbo on and end up with the exact same issues.

Anyone has any idea what else besides wastegate port size can cause boost creep on 8l S3?

 

[Garrett 69]

Depends on when it was made, I left Borg Warner about 7 years ago.

 

[Shaun220]

Depends on when it was made, I left Borg Warner about 7 years ago.

Guess will need to just fit it and then test and confirm for now.

 

[Shaun220]

Just an update. fitted the new original Borg warner K04-023 turbo. Took it for its first drive, it spiked hard to 1.6bar on first gear. I have not had a chance to confirm wastegate pressure, I will take it for a drive with n75 electronically disconnected to see what we get. Will keep you updated.

 

[Shaun220]

Hey guys.
A update on my overboosting issue.

So after the replacement of my turbo, on wastegate only, the car holds at 0.5bar throughout the rpm range.

But with n75 plugged. I am getting overboosting issues.

I have a new oem turbo and actuator fitted.
A new agent n75 valve fitted.
A new agent map sensor fitted.
We scanned the car with Vagcom and no errors.
Boost and vacuum leak test done with pressure and smoke,so no leaks found.

I have taken the car to a tuner and on the stock file on the dyno, the requested boost is at 1900mbar, which in turn is about 0.9bar. but actual is 1.6 bar.

We have tuned the car, but still runs over the actual. On the dyno in a 3rd gear WOT pull, the car continuosly dumped boost and gets back in it.

Were else can we go from here to troubleshoot the overboost issue?
Any ideas will be appreciated as I am lost now trying to get this resolved.