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I’ve had my 2008 S8 for awhile now, it has the LR Amaretto interior.
Ibis White seemed to be a neutral color, but when parked next to my other car that's Pure White, it's apparent it has a warm tint.
I installed a VTA (vent to atmosphere) type of catch can, in preparation for intake carbon cleaning.
I've been driving with it for a few months, every gas tank full I empty it, most of what comes out is water with some foamy oil mixed in.
Pull the hook tubes off the connector part of the two breather hoses, grind the end of the connectors down to be able to fit into one straight and the angled PushLok ORB fittings, then epoxy together;
Left side engine valve cover connection, and FOS (fine oil separator) intake plugged;
Right side engine valve cover connection;
The catch can openings aren't threaded, and are tapered, so the three fittings (other straight PushLok ORB fitting, the barbed fitting for the filter, and the petcock fitting) with O rings removed needed to be filed down slightly to a tapered shape to be able to screw in and epoxy;
Tie wrapped the catch can into the right fender area;
The petcock is retained in a hole in the under tray;
Pull out from underneath to drain;
I ran five bottles of PEA based Redline SI-1 through the intake in half bottle (7.5oz) increments, which seems to have had some cleaning effect, as the car accelerates smoother and stronger;
To clarify, after driving and bringing the engine up to temperature, I ran the Redline SI-1 into the intake so that it would coat the hot valves and surrounding area.
Then I let it sit until the next drive, after warm up it would flash and smoke would come out of the exhaust, the first would be the most, then less and less after each acceleration.
I repeated that ten times over a week or so.
After a few months the ProVent 200 started to make honking sounds, so I opened up the fender liner to see that the noise was from the over pressure valve opening and closing, as there was a coating of oil on the outside of it.
I removed it and found that it was full of oil sludge and water, the oil had saturated the fiber filter and was preventing the water from draining.
If there was suction on the outlet side, instead of just the VTA filter, the blockage may not have occurred.
Others have had the same issue; https://www.audizine.com/forum/showt...ovent-recently https://www.audizine.com/forum/showt...-oil-separator https://www.audizine.com/forum/showt...=provent+julex
I've ordered a SS mesh filter that should allow the water and oil to drain better, and the remaining crankcase vapor that does get through should be trapped by the VTA filter;
Why would you want to spend money to create problems to fix? Another garage engineering product that you found? Thanks for posting, I'm sure the S8 owners will stay clear of whatever you're installing.
Cheers,
Louis
Why would you want to spend money to create problems to fix? Another garage engineering product that you found? Thanks for posting, I'm sure the S8 owners will stay clear of whatever you're installing.
Cheers,
Louis
I'm not entirely certain what your concern is Louis, but the problem is that a direct injected engine is susceptible to intake valve carbon fouling over time, as the fine oil separator isn't 100% effective in removing oil from the crankcase vapor that is then directed into the intake.
Also, under high engine speed and low load, a bypass valve opens and allows unfiltered vapor to pass.
I installed the VTA catch can so that after I clean the intake ports and valves, I don't have to do that again down the road.
Your direct injected Q7's engine is slowly being strangled, you may not care about that though.
I feared the 2007 and later A8 because of carbon fouling (also timing chain at the firewall).
After this problem, Some manufacturers have later reverted to installing a small fuel injector to help wash off the valves.
Its a a real problem, and as you suggested, many are not even aware of the slow loss of performance over time.
I've done a similar thing. I just have to route a hose to the back of the car to keep exhaust fumes down.
I kind of like the occasional faint oily smell, reminds me of 60s era and earlier cars.
Temporarily removing the catch can, and routing the hose capped by the VTA filter below the under body cover opening, I have none.
After ~8K miles less came out each week when I opened the petcock.
It had been mostly water with a little sludge, so I took the catch can out to take a look.
There was oil surrounding the area where it was mounted, which had come from the relief valve after the filter had filled up with sludge.
Since it's warm weather, I would have thought that the sludge would drain better, but without suction from the other side it stays in.
I don't want to route that side into the intake, so for now it exits under the car.
12-01-2018, 01:17 PM
T9T9 Ibis White (S8) - journal
