Titanium Grey S4 Avant

[newsh]

Because one side is blocked

[hunker7]

Your silencer has fallen to bits inside

Why do you think so?

[hunker7]

Some of it is vapour, but that usually dissappear's quickly, but some of that smoke stays around for a while
.

I can't test it till I get back to London in a month time.

[newsh]

Your silencer has fallen to bits inside

[UrS4boy]

Last summer I had all the pipework off and it was all washed and cleaned and washed again.

Some of that "smoke" in the video isn't smoke, its water vapour, i.e. nothing to worry about.

Assuming nothing bad has happened since you cleaned and maintained the PCV system, you might want to determine whether one or more of your catalytic converters is plugged, causing a back pressure.

[hunker7]

Last summer I had all the pipework off and it was all washed and cleaned and washed again.

[UrS4boy]

AAN/ABY/ADU Positive Crankcase Ventilation (PCV) System with revised diagram, PNs and

What could cause PCV blockage?

Years of lack of maintenance.

Mike74 on the S2Forum was having missing/hesitation issues with his RS2. He did a boost leak test and found issues with a failed one-way PCV ball valve and the pressure regulating valve. He replaced both and now things are good. He dissected the pressure regulating valve and found that it was very coked/oiled up inside. This probably suggests that periodic (every 2 years??) removal of the pressure regulating valve and cleaning it inside with solvent would be a good idea.




Item 3 below:



REFERENCE:

AAN/ABY/ADU Positive Crankcase Ventilation (PCV) System with revised diagram, PNs and Links:

http://forums.quattroworld.com/s4s6/msgs/22506.phtml

[hunker7]

You can see some black smoke slightly but it's clear that one side of the exhaust isn't doing its job

[hunker7]

I had the head off at the start of the year and valve guides were not very worn. What could cause PCV blockage?

Blocked exhaust would also explain sluggishness at higher loads.

[Error404]

Valve stem seals only really stop oil running down the stems when the engine is shut down.
If you have blue smoke on idle only I would suspect worn exhaust valve guides or blocked PCV system.

[hunker7]

Just started her up, no blue smoke, but kicks out black, and did a quick video and one side of the exhaust seems to be blocked.

[hunker7]

Does the spare set leak?

I've put them in now, leave them till tomorrow and try then.

[UrS4boy]

Injecotrs doesn't seem to be leaking, but I put spare set I had in to see if that helps. Today it was blue smoke only, so I assume it's oil, but valve seals are new Any ideas?

Does the spare set leak?

[hunker7]

Injecotrs doesn't seem to be leaking, but I put spare set I had in to see if that helps. Today it was blue smoke only, so I assume it's oil, but valve seals are new Any ideas?

[UrS4boy]

btw, you wouldn't know which wire does what for clock? I assume there is +12v ground and signal to set it?

LOL. I wish. I started a project to swap 200 20Vt gauges into an UrS4 and I could never get the proper wiring diagrams. When I actually tried it, it failed.

The starting point: http://forums.quattroworld.com/s4s6/msgs/304202.phtml

The failure point: http://forums.quattroworld.com/s4s6/msgs/307449.phtml



Problem is I don't believe this diagram (which I coloured):