Boost pipes collapsing and starving engine

Enkidu

Member
Joined
Apr 20, 2017
Location
UK
TDI
1.9 AVF
Hi

I'm really having trouble with my car, its a 1.9 AVF passat 4motion. Bit of background...

Car broke down last week, boost pipes collapsed and it wouldn't start. I ended up popping off the pipe to get me home. I had a cheap ebay recon turbo on there, I have now changed that for a proper one but its still doing it. I'm so gutted as now i'm changing parts that weren't faulty. What else can it be?
 

imo000

Top Post Dawg
Joined
Dec 13, 2005
Location
Cambridge
TDI
2009 M-B ML320 Diesel & '05 Passat TDI Manual 5-Speed
How can a boost pipe collapse? Is it kinked or collapsed? Post a picture of the collapsed pipe.
 

Enkidu

Member
Joined
Apr 20, 2017
Location
UK
TDI
1.9 AVF
How can a boost pipe collapse? Is it kinked or collapsed? Post a picture of the collapsed pipe.
Good question, how... I will get some pics up tomorrow morning. I mean like a McDonald's straw collapsed from thick milkshake.
 

1854sailor

Resident Curmudgeon
Joined
Aug 10, 2004
Location
Westerly, RI
TDI
2015 Golf SE SportWagen, 2015 Golf SE Hatch Back.
Which hoses collapsed? Have you checked the intake for blockage?
 

Enkidu

Member
Joined
Apr 20, 2017
Location
UK
TDI
1.9 AVF
Which hoses collapsed? Have you checked the intake for blockage?
Had the intake off loads, nothing there. Unless the paper air filter somehow sealed the air off (it's recently replaced) i cant see what's blocked. The pipes i can immediately see that's vacuumed tight is the two before and after the intercooler. Only thing before there is the hardpipe that runs under radiator and the pipe that goes to the turbo. I will take the whole lot out and check again... Can they somehow delaminate internally ??
 

Enkidu

Member
Joined
Apr 20, 2017
Location
UK
TDI
1.9 AVF
I found a soft section on the turbo to hardpipe part of the boost hoses... I wonder if that's collapsing when I'm off throttle? £130 part FFS.
 

Scubanero

Veteran Member
Joined
May 30, 2007
Location
Calgary AB
TDI
2005 Passat Wagon
That is the turbo discharge and is normally under pressure. Even at low boost, all that changes are the inlet guide vanes that are on the exhaust side, so no restriction on the intake side. Try a different air cleaner. Failing that, open things up and use a vacuum cleaner to check for obstructions in the charge air circuit. 130 GBP is cheap for that hose compared to North American prices.
 

imo000

Top Post Dawg
Joined
Dec 13, 2005
Location
Cambridge
TDI
2009 M-B ML320 Diesel & '05 Passat TDI Manual 5-Speed
Pull the air filter and go for a short drive.
 

Enkidu

Member
Joined
Apr 20, 2017
Location
UK
TDI
1.9 AVF
Yeah it's up and running, it was the boost pipe just aged and had a soft spot. Car back up and running, cheers all.
 

denpar

New member
Joined
Aug 20, 2017
Location
navarre fl
TDI
2006 jetta
I know this is an old thread but im having this same problem on my 2006 jetta tdi. Pipes going into intake collapse, I pull it loose from intercooler and crank car and it will run but there is no air coming out of intercooler. Anybody have any ideas thanks Dennis
 
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