AndrewsQuattros

It works... for about 5 minutes ;-)
Well my over-boosting problem is most likely the MM hose, nice big gash on the bottom of it... I was told it was fairly new (it even looks pretty new), so that was the last thing I checked... may have been defective? Just hadda try the duct tape though. heh.

MarkPan

duct tape, electrical tape and zip tie combination.

it should give you UNDER boost though, as its a huge vacuum/boost leak

Jon Clay

after I'd siliconed it all the way around. After about a month of driving at 12psi it finally needed to be replaced.

I don't think a torn MM hose would cause overboosting, though.

AndrewsQuattros

For overboost one of the things suggested was to check for a rotted lower IC hose... well wouldn't the MM hose (aka: upper IC hose) be an equal suspect? Based on suggestions I would think that with a small leak of measured air it would somehow(?) result in overboost, then once the leak gets worse and a big sum of air escapes it would under-boost. Could this be true?

To get more in detail, the car overboosted for a while, now it doesnt overboost, but you hear a loud wooooosh. My thought would be the tear started out very small causing overboost and then it got bigger causing the lower boost. It's an Audi though so it may very well be two completely different problems Perhaps the WG solonoid is also shot... Well my best bet is to first replace the MM hose and see what happens.
I appreciate the input and any other suggestions as I'm sort of new to these turbo cars.
Thanks!

boxerfan

A little of the "ol' handyman's secret weapon" never goes amiss... a la Red Green.

boxerfan

a leak on either one will limit your boost NOT cause overboost. If the hole gets large enough there will be enough air leaking around the CIS pressure plate to stop the car from starting whatsoever.

Overboost is commonly a torn WG diaphragm.

Tom Faust

I suspect that vibration/flexing are more the problem. Try some rubber bumper patching paste (don't know if you can still get it in small quantities since bumpers are now urethane. The last rubber bumper kit I got was from 3M and cost $25.00) and duct tape.

CARSNPLANES

large vac hose under the wastegate. That is one of the hoses yu can pull off, plug for troubleshooting to check to see if turbo, wastegate is putting out potentially good boost. It will cause FP cutout if exceeds 1.7 or something like that.
See SJM site on this subject.<ul><li><a href="http://www.sjmautotechnik.com/trouble_shooting/boost.html">http://www.sjmautotechnik.com/trouble_shooting/boost.html</a</li></ul>

Scott Miller

I haven't tried it, but I carry it and I'd expect it'd work better than duct tape. It's sort of like heat-shrink tape, made for high temp and pressure fixes. Where does 19psi come from?

Avant Sport

Lower WG hose perhaps, not lower IC hose.