No boost, sounds like I blew a charge pipe but everything seems connected

[Randal McDowell]

Earlier this week my mk4 ALH started making a noise that sounded something like a whine that only really happened when I layed into the throttle hard. Took the skidplate off yesterday and the exhaust is rusted through so I took off the back half so it doesn't just shake around, but the whine didn't go away. We reassembled everything and took it for a drive, noticed it was slow to spool up, then got to around 20psi and made the noise it makes when a charge pipe came off, but brought it back in and the line all look solid. Any ideas? was thinking maybe n75 valve but i've never had one go wrong so I'm not sure if the symptoms match or not. Car has a VNT 17 and a stage 4 tune, replaced all vacuum lines a year or two ago.

 

[super1]

VCDS Scan ?

 

[Randal McDowell]

VCDS Scan ?

Just ran a scan and nothing engine related at all, which is weird in itself for this car. It usually throws a injection pump timing code but this time nothing.

 

[super1]

Just ran a scan and nothing engine related at all, which is weird in itself for this car. It usually throws a injection pump timing code but this time nothing.

Maybe one of the hoses has a small hole in it?

 

[Nero Morg]

The hoses can split a small hole and sound like a boost pipe has fallen off, also if you have any Egr pipes in place, they can split and cause the same noise. Even if you have a block off plate they can leak. Check everything with a fine tooth comb.

 

[Randal McDowell]

The hoses can split a small hole and sound like a boost pipe has fallen off, also if you have any Egr pipes in place, they can split and cause the same noise. Even if you have a block off plate they can leak. Check everything with a fine tooth comb.

I checked it pretty thoroughly last night and just checked everything on the top side and can't find anything, and I feel like to get the kind of leak i'm hearing I would be able to see the hole

 

[LoopyTDI]

I checked it pretty thoroughly last night and just checked everything on the top side and can't find anything, and I feel like to get the kind of leak i'm hearing I would be able to see the hole

Last time i had a leak it was the egr cooler pipe gasket that was leaking it was making a weird whining noise when i got into boost

 

[Randal McDowell]

Last time i had a leak it was the egr cooler pipe gasket that was leaking it was making a weird whining noise when i got into boost

I forgot to mention I've removed my anti-shudder valve so it isn't leaking from that egr port, but I suppose it could be leaking from the egr port on the exhaust manifold

 

[LoopyTDI]

I forgot to mention I've removed my anti-shudder valve so it isn't leaking from that egr port, but I suppose it could be leaking from the egr port on the exhaust manifold

Yep or any gasket in that area

 

[Nevada_TDI]

Years back, I threaded in a 1/4NPT fitting to attach a boost gauge to, the fitting somehow blew out, and lost so much boost it was ridiculous. That said, a small hole can leak a lot of boost.

 

[Randal McDowell]

UPDATE: Went for a drive to return some stuff to autozone, still 0 psi of boost but now its burning oil like i couldn't imagine, like throwing a smoke screen up behind me. Drove it back home (the whole trip was probably 2 minutes) and checked oil, completely empty. Could I have popped a seal or something? and if so where would I start to look?

 

[Genesis]

I smell a turbocharger failure....

 

[Randal McDowell]

I smell a turbocharger failure....

MAN what a bummer. I didn't want to say it but that definitely could be, theres a small lake of oil under the turbo, I think its coming out of the exhaust side right now. This turbo is less than two years old, how can I avoid this happening again?

 

[Nero Morg]

Overspooling is usually the cause of dead turbos. Overspooling can be caused by boost spikes, boost leaks, and sometimes overfueling.

 

[Randal McDowell]

Overspooling is usually the cause of dead turbos. Overspooling can be caused by boost spikes, boost leaks, and sometimes overfueling.

Now that you mention it, it did have a pretty bad boost leak i didn't notice for the first several months. By overfuelling you mean too big of injectors? I have the Bosio PowerPlus 520's from kermatdi, would this be too much? What kind of boost spikes also, like high pressure to low pressure?

 

[Nero Morg]

If you are blowing some bad smoke, your injectors or your iq is too much. If it's always been a light haze, you can probably rule that one out.

Yes a boost leak for several months can definitely cause a turbo to wear out prematurely.
As for boost spikes, instead of having a nice clean boost increase, a boost spike is where it goes really fast past your tuned boost max limit, then rolls back into the max boost level. Boost spiking can be caused by boost leaks, worn actuator, bad n75... Pretty much anything on the turbo control side.

 

[Nevada_TDI]

Having a boost leak can cause turbo failure as the MAP sensor keeps telling the turbo to make boost and over spooling kills the turbo.
With zero boost and oil in the tailpipe, and no oil in the crankcase: dead turbo.
You got really lucky you did not have a runaway seizing the engine.

 

[Judson]

The whine sounds exactly like turbo blades hitting the housing. I know this sound too well. Now, chewing up oil means your turbo shaft is broken and oil is getting into the intake.
You’re lucky methinks to have not had a runaway…