Over boost fault

[Ivo]

When things cool down (your inlet), the engine creates boost more easily. That "rattling" noise you can hear is the wastegate fluttering like mad trying to dump exhaust pressure to alleviate the boost spike.

Thanks for the info mate. Is there anything I an do about it? Is there something causing the problem that can be fixed?

[gregozedobe]

That "rattling" noise you can hear is the wastegate fluttering like mad trying to dump exhaust pressure to alleviate the boost spike.

IIRC recent VW TDIs don't have wastegates on their turbos, only Variable Vanes (older TDIs did have wastegates). But the rattling noise could be a problem with the VV actuator.

IIRC there have been some threads somewhere (here or TDI club forum, a search might find them) about freeing up the VV actuator when they are only a bit sticky (rather than completely stuck in one position). It seemed to be a bit difficult to do with the turbo in situ (a fair amount of force needed, plus very poor access).

[Preen59]

From what i've been told (by someone on here.. can't remember who) some of the TDI's have a wastegate aswell and some do not. I have heard the caddy fluttering on a number of occasions right in the peak torque band in second gear and it's always when the air is dense. It sounds exactly like a wastegate to me, however i've never been arsed to look further into it..

[Preen59]

Thanks for the info mate. Is there anything I an do about it? Is there something causing the problem that can be fixed?

Pretty much what Jmac said i think. I'm not a mechanic so i won't comment and steer you in the wrong direction.

[Transporter]

Has anyone experienced their 2.5L T5 over boosting then cutting power and going into limp home mode? Turn the ignition off then goes back to normal untill over boost is picked up again? Any help much appreciated.

It is not uncommon that TDI even with moderate mileage suffer from variable vanes seizing (high temperature and sooth particles), because of the tight clearances between moving vanes and turbo casings.

Some mechanics on this website
http://dieselpower.cz/forum/viewtopic.php?t=1874 (you won't be able to read it, but the pictures are worth a thousands of words )

repair it with dismantling, cleaning and installing thin washers between vanes and two turbo halves, so there is a little gap created.

I couldn’t find the exact thread with the washers installed, I saved it somewhere on my pc but I can’t find it now.

edit: I found it now,
http://dieselpower.cz/forum/viewtopi...ovaci+podlozky

Here is small translate with couple of pictures I put in the thread in our section:

http://www.vwwatercooled.org.au/newf...03&postcount=5

[Ivo]

Hmmm should I be worried if my mechanic takes to my engine with an angle grinder that big?

Thanks for all the info fellas!

I was thinking it would be so much easier to just spray something in there to clean it out so I did a quick search and found this product.
http://www.innotecworld.com/c-1064-turbo-clean-set.aspx Not sure if you can buy it here or not?

Is there any other way of cleaning it with taking the entire turbo off?

[gregozedobe]

Is there any other way of cleaning it with taking the entire turbo off?

I haven't read of any other effective way if it is truly jammed.

[Ivo]

Just found this thread....
http://forums.tdiclub.com/showthread.php?t=246287

[Ivo]

I have been doing a bit more research on this. I know a bloke who used to be an interstate truck driver for 25 years. His recommendation is add a VERY small (cap full) of petrol to a tank full of diesel occasionally to kill the algae that can grow in the tank and also clean out the fuel system.

He also suggested steam cleaning the combustion chamber and exhaust manifolds etc by taking the air filter off, holding the revs high on a running engine and trickle/mist 0.5lts of water very very slowly into the air intake. The idea is to create steam that removes all the carbon but not in quantities that will damage the engine. He also said that when doing this make sure the engine and exhaust is up to operating temperature and that the exhaust is aimed away from anything as the black muck that gets blown out is filthy.

Any thoughts?

[Ivo]

Water down the intake study.

http://www.files.thinksitout.com/Alt...f%20engine.pdf