S8 5.2 Intake Manifold removal and cylinder cleaning
12-30-2012, 03:02 PM
#31
AudiWorld Member
I found some information in the study guide that supports my theory, starting at page 10;
Crankcase Ventilation
Blow-by gases created during the combustion process must be ventilated from the crankcase. Excess blow-by can cause sludge and acids, leading to coking of the intake valves.
...and at page 11;
When the engine is running at very low load but at a very high RPM, the piston rings can begin to flutter. The blow- by gas pressure is very high and the fine oil separator
is unable to operate at its peak efficiency. At this point, the by-pass valve opens and a fraction of the blow-by gas flows to the intake manifold untreated. (See bottom illustration.)
So make sure your Fine Oil Separator is working correctly, and don't run the engine at low load and high RPM.
I noticed there was a little sludge baked onto the inside of the connector upstream of the separator, so it's possible that the separator itself could be affected.
I've run a can of Sea Foam in the crankcase for the last 100 miles before the last oil change, and it appeared to have loosened some gunk judging from the state of the oil filter.
http://www.1stcallhosting.com/tech/a...cc+V10+FSI.pdf
Crankcase Ventilation
Blow-by gases created during the combustion process must be ventilated from the crankcase. Excess blow-by can cause sludge and acids, leading to coking of the intake valves.
...and at page 11;
When the engine is running at very low load but at a very high RPM, the piston rings can begin to flutter. The blow- by gas pressure is very high and the fine oil separator
is unable to operate at its peak efficiency. At this point, the by-pass valve opens and a fraction of the blow-by gas flows to the intake manifold untreated. (See bottom illustration.)
So make sure your Fine Oil Separator is working correctly, and don't run the engine at low load and high RPM.
I noticed there was a little sludge baked onto the inside of the connector upstream of the separator, so it's possible that the separator itself could be affected.
I've run a can of Sea Foam in the crankcase for the last 100 miles before the last oil change, and it appeared to have loosened some gunk judging from the state of the oil filter.
http://www.1stcallhosting.com/tech/a...cc+V10+FSI.pdf
Last edited by EHLO; 12-30-2012 at 03:36 PM.
10-07-2015, 05:35 PM
#32
AudiWorld Member
I'm doing mine at the moment. It is time consuming as each cylinder has to be rotated until both valves are closed. One cylinder at a time. Soak first then chip and vacuum.
10-10-2015, 01:54 AM
#36
AudiWorld Senior Member
10-12-2015, 03:54 AM
#38
AudiWorld Member