yet again mk3 golf power loss

[payton31]

i can be going to over take say at 65 in third and once you reach about 3600rpm the turbo completely dies off and if you take your foot off and put it back on the power will return for about 5 seconds.

this happends in 3rd,4th and 5th it is really annoying when you cant go faster than 85 on a motorway sureley theese cars do more than that.

i have checked all the previous threads ,

changed the ecu hose, changed the n75 valve, changed most of the pipes from the n75.

made sure the pipe to the acuuator is on tight with no leaks.

plugged it into my vag-com and came up with

00575 - Intake Manifold Pressure
17-10 - Control Difference - Intermittent

any other ideas cus im gettin to the stage now of thinking of just buying a new turbo.

its really annoying me.

thanks in advance for any help cheers

[chittychittybangbang]

That code is air leaking out. If you're sure the n75 and ALL vacuum lines are good, you may have a boost leak somewhere. Some possibilities are the rubber intake piping and couplers.

Other possibilities are a bad wastegate or bad turbo. Apply air pressure to the wastegate and it should move the wastegate arm. It should also hold the pressure.

It could also be fuel related - bad fuel filter, clogged fuel filter, clogged fuel lines or fuel pick up at the fuel tank, bad injection pump. However, fix the error code first.

[payton31]

I'm pretty sure they're all not leaking at all. What you mean by couplings ?

[shftdrvr]

Have you done a boost leak test? There's a writeup in the FAQ section. I think he means the couplers = hose connectors.

[chittychittybangbang]

Yes, where the hard plastic intake piping connects to other stuff there are rubber couplers. These can split due to age and heat or slip off. If you want to solve this problem, look at all the more common causes of limp mode and power loss. One of these is doing a boost leak test or at least manually inspecting all the intake piping and checking ALL the vacuum lines. Otherwise you'll waste time checking the other stuff.

[payton31]

I have checked all vacuum lines i hadn't done a boost leak test yet as I have not got the correct equipment

[payton31]

Anyone got any better instructions on a boost leak I tried with the plastic bag and the car just sucked in the plastic bag does this mean it's getting to much air in the intake ?

[chittychittybangbang]

Woah, please read the full article before you run tests. Did you do this test with the engine running? The engine must be off and you must use compressed air to pressurize the intake path. If the plastic bag gets wrapped around the turbo you just ruined the turbo.

[payton31]

Oh na I didn't let the bag go through like. I got confused so.... It's really driving me mad now I'll try again in the morning. Thanks any other advice ?

[BillK]

Have you changed ALL the vacuum lines? Check all the easy stuff first.