Boost Problem - (**New Picture added Pg2 - Please have a quick look**)

[martziniuk]

It logs n75 duty cycle. The higher the number the harder the turbo is working to meet specified boost. It's quite useful to detect leaks as when the duty cycle numbers are higher than what is deemed normal something's leaking.

[GTI-Ross]

So went out tonight and did two N75 runs, both look very different. First one look pretty bad as it drops all the way down to 63.5% but then the second one looks pretty decent. Can anyone shed any light what might be going on. Both 3rd gear pulls to redline (approx)

[xjay1337]

Correct me if I'm wrong but it should never be 100% that means the turbo is working as hard as it can...

I was always under the impression that a duty cycle of around 75-80% under full throttle should be what you have..? That was when it came to diesels however.

[GTI-Ross]

Correct me if I'm wrong but it should never be 100% that means the turbo is working as hard as it can...

I was always under the impression that a duty cycle of around 75-80% under full throttle should be what you have..? That was when it came to diesels however.

It should be @ 100% till it hits needed value and then should try to maintain (85%-95%). but both logs are very different. Here is the boost log, Requested vs actual for second graph shown in PSI. Wierd?

[xjay1337]

Maybe take it to a tuner who can do some live logging and diagnostics..

[GTI-Ross]

Maybe take it to a tuner who can do some live logging and diagnostics..

Wish there was a decent VAG Tuner in my area. Anyways, im going to order the intercooler pipe seal / gasket and see if that fixes it, then go from there 

[mdmay]

Where are you Ross?

[GTI-Ross]

Where are you Ross?

Bradford / Leeds mate.

[Markyed30]

Any further forward yet Ross?

[GTI-Ross]

Any further forward yet Ross?

Not really yet, my VW garage (who are decent fella's) are going to look at it next week, see if they can spot an boost obvious leak. For me its got to be the DV, Intercooler seals or the N75 valve. Im going to run a few more Boost vs N75 logs tonight.

I was under the car yesterday and took this photo. There is sh*t ton of oil here, which would generally mean a duff DV, but I only replaced it about 2 months ago with revision G valve. I cant see where else the oil would come from. I just hope its not coming from the turbo its self. I mean the car still boost decent, just not matching the high request

[Markyed30]

Nothing worse than something niggling hope it's something simple if it's leaking from dv is it possible it's leaking where the two join mibby the rubber gasket on the dv?

[GTI-Ross]

Did another 3 Runs tonight and logged. It seems to be making close to requested Boost now, (which is strange as it was quite so way off the other day) but the N75 shouldn't be going to 100% as often as this....so weird 

[bacillus]

Go get a smoke test done. It should show you where the system is leaking boost.

[GTI-Ross]

Go get a smoke test done. It should show you where the system is leaking boost.

How much do they cost roughly?

[56OctyVRS]

Things such as temperature and air pressure can alter make a big difference on how the engine performs. Id really get it put on rollers to get it logged. If you are in leeds, rtech are only an hour and a bits drive away. If you had a boost leak you would get a fault code of P0299 of underboosting. I had this fault but it was the map rather than hardware.