Audi 80 Avant

[A80Avant]

small correction,
after looking through more logs, the boost still seems to be dropping from 2bar to 1.7bar on the red line. This may well be due to backpressure, but im wondering where....

any help and thoughts would be appreciated.

[Rocco]

small correction,
after looking through more logs, the boost still seems to be dropping from 2bar to 1.7bar on the red line. This may well be due to backpressure, but im wondering where....

any help and thoughts would be appreciated.

are you still with cats?? they could be dirty...

[A80Avant]

sure, i use 2 of them.
question is, why would they be dirty all of a sudden?

or could they have had so much blowby that the whole tract has been contaminated?

[A80Avant]

well after a lot of talk and consideration with Jade(thanks) and JP, i have now got a new catch tank made here in Greece to the spec that i needed for the mounting area, and i also have the provent bottle as well.

Both will be fitted and along with a check valve on the return line to the sump, a modification of the pipe that runs in the camcover to become a breather pipe, hopefully the blowby issue will be sorted.

The schedule goes like this:
Next week: solving the brake servo issue with a lot of help from forum members sorting out parts and modifiyng things to fit a RHD to a LHD car. Also a compression check will be done to see if there is anything major wrong with the piston rings.
Following week: Wastegate, catalysts check will be done, to see if there is any issue with increased backpressure. If everything checks out as being OK, i will have to take the turbo off and sent back to turbodynamics, as it may be that it will have a problem. Im still under warranty so hopefully it wont cost me anything, unless i decide to try out the billet wheel to see what the gains will be.

im hopeful that the car would be ok to go to the July meet at MRC, but if not, and if the piston rings have had an issue there, i may not push the car until next year when ill have to drive back home again for another big service including a head treatment, rod bearings, piston ring replacement etc.

Afterall, the engine has already done about 100K kms since rebuilt and i would expect things to start wearing a bit.!! haha

[prj]

Also a compression check will be done to see if there is anything major wrong with the piston rings.

Compression check may not show anything.
You should do a leakdown test.

I had similar issues as you - oil pushing everywhere from PCV, and my compression was perfect.
Leakdown was horrible though... replaced rings (and a few other things) and all is well.

[Billman]

Compression check may not show anything.
You should do a leakdown test.

I had similar issues as you - oil pushing everywhere from PCV, and my compression was perfect.
Leakdown was horrible though... replaced rings (and a few other things) and all is well.

How is this done?

[A80Avant]

Replacement of piston rings and redoing of the head is already planned, so if my compression is ok, then im sure that the engine will continue runnning ok until i drive back home. I doubt that this garage will know how to do a leak down test. If they do, ill see whats going on,but ill still be changing rings next year at the earliest unless the engine cannot run.

What are the 'other things' you replaced?

[prj]

What are the 'other things' you replaced?

[A80Avant]

ah, so more or less a head rebuilt

ok

[A80Avant]

any specific recommendations of piston rings for mahle pistons 81.29mm?

[Billman]

found some info here

http://www.aa1car.com/library/leakdown.htm

[A80Avant]

well compression test seems low, and car is a bit thirsty on oil. Nothing serious, still running, but PCV system got installed a bit too late i guess.

One order has gone through for parts and second will be soon. Hopefully car should be making me happy again within a few months time.

[A80Avant]

Just so that i can have 6600 posts...
Brake fluid tank and hydraulic servo is getting the hell out of there soon...
If the system still doesnt work, it must be the ABS system by the way(but i doubt it, as i loose pressure when idle and pedal has been pressed a few times, then once on the move and the revs build up, the PAS pump rebuilds enough pressure to make the brakes operational again.)

[Bram]

Still upgrading?

[A80Avant]

If brakes dont work, engine is burning oil, while clutch is smelling on occasion on normal driving and gear change, and fixing that is called upgrading, then yes...