Audi A3 intercooler issues

Burnerman · 10 Aug 2011

So - the vehicle of the day is an A3, 54 plate 2.0 tdi.
Every time the engine is revved up, one of the pipes blows off the intercooler and the engine will hardly run after that.
So, I've replaced the clip (one of the usual VAG 'U' shaped spring things) and popped the pipe back on. All seems snug.
Drive up the road, and the pipe is back off in 50 yards.

Underneath, the pipe feels as if its being held properly, but I'm wondering if the intercooler pipe stubs has been damaged somehow.
A new one on me! Any comments anyone?
Have a good evening
John

Peter.N. · 10 Aug 2011

You get some good jobs John don't you

I suppose the intercooler is not blocked with something and the excessive pressure is pushing it off, the engine hardly running with it off made me think of that.

Peter

Burnerman · 10 Aug 2011

Peter, you may well have a point - I'm used to the crazy pressures produced by turbo's these days......often you can feel the pipes expanding under pressure.
However, the car performs well until the pipe blows, and then it will hardly move. I presume this is due to pressure sensors backing off the injection system but it goes further than a get-you-home mode - the car will hardly drive at all, and I just got it back in first gear. As for the engine performing in non turbo mode - no chance.
Another theory which I'll look at is if the engine is moving excessively it could cause the pipe to wrench free.....with the car on jacks all seems to be reasonably well even when revved to maximum- its just when you drive it away the pipes blow off.
Thats tomorrow taken care of then, I need to talk to the Audi guys and see what they say.
Good evening

John

seco services · 10 Aug 2011

i've heard the hoses wear on the raised alloy section that acts against the clip.
New hose useally sorts it.

Mursal · 10 Aug 2011

Instead of a dump valve (gate valve) I think that engine has a variable vane in the turbo to control max pressure? A little lever sticking out of the turbo with an actuator attached.

It's never stuck in the boost position and the actuator can't pull it back?
They stick in the low pressure but never head of them sticking in the high pressure before.

Otherwise the bottom of the intercooler radiator is clogged with oil/gunk.

Burnerman · 11 Aug 2011

Thanks for the replies and suggestions gentlemen - most appreciated!

I'm getting more of the full story now - apparently when the hose first blew, the clip was broken in two, so the owner got a new clip which I fitted.
Much to my surprise, the hose blew off again. I guess the hose end has been chattering within the plastic intercooler box and either split things or caused some wear, so I guess new bits are needed.
Part of me thinks of fixing the bits together with some self tapping screws but access is very difficult.
John

gblades · 11 Aug 2011

My A4 have a recirculation valve instead which basically connects the inlet and outlet of the turbo together. I believe its vacuum operated.
A split in the vacuum hose or a worn through plastic diafram in the recirculation value are common causes for poor turbo performance but depending how bad its got doesnt always result in a fault code being shown.

Burnerman · 16 Aug 2011

Update on this one......the turbo pipe has raised aluminium 'nibs' that allow the spring clip to engage onto - or at least, this one had! They are completely worn away.
Seco - 10/10 and you win a cookie

Intercooler £237 + vat
Hose £36 + vat....that should make someone smile!
Have a good evening everyone
John

seco services · 16 Aug 2011

Burnerman said:
Seco - 10/10 and you win a cookie

Thank you.

millerman · 17 Aug 2011

gblades said:
My A4 have a recirculation valve instead which basically connects the inlet and outlet of the turbo together. I believe its vacuum operated.
A split in the vacuum hose or a worn through plastic diafram in the recirculation value are common causes for poor turbo performance but depending how bad its got doesnt always result in a fault code being shown.

My car also has a recirc valve and a duff diaphram will result in LOST boost and as Johns hose keeps blowing off i would suspect boost issues are not a problem.

EDIT; just noticed the prob is fixed, must pay attention.

Audi A3 intercooler issues

Similar threads