Greetings,

06 Flying Spur.
Doing some initial purchase maintenance on upper part of engine...PCV cleaning, MAF cleaning, MAP cleaning, intake manifold cleaning, spark plugs, coils, valve cover gaskets, B12 piston soak, intake valve carbon cleaning, etc.

Was hoping someone would be able to help me out, or maybe they've gone through this before.

1. Took the MAF sensors off, both are split open as pictured. Is this normal (open and close on their own or something)? Ebay ones (used) appear cracked open too, new ones appear closed online.
2. Want to remove valve covers to do gaskets since they're cheap. Can't figure out what to do about these 2 circular gaskets on the cover with the wires sticking out, they're in the way. Can they be unplugged 1st? Where? How? Take cover off first, then unplug them from the inside? I have the replacement gaskets for these little ones in question.

Also, my car has 250k miles (yes, quarter million). Curious, anyone on here got that much. Is that a lot for a W12? I would think not.

 

Hello @rsebastien1993 ,
As far as carbon build-up, you shouldn't have any, as our engines have port fuel injection to wash the intake valves, where others with direct injection into the cylinder itself, those intake valves suffer from carbon build-up from timing overlap, and the lack of fuel in the head just above the intake valve.

As to the MAF, no it shouldn't be split open, that is odd, I wonder if someone prior pried it open to clean.
I just went out to the garage and took pictures of the two spare MAF's I have, see below.

As to the wires for the VVT's in each valve cover, you have one reddish orange and one black on each side, (in most of my pictures, mine are white/gray and black, as my engine is a 2011, except for the 07 I broke down as pictured) just wiggle each connection out of their mounting bracket by rotating left and right while pushing towards the firewall, then unplug each, then when you remove each valve cover, you slide the plug through the hole for each, it will be tight on your hands, so take your time and be relaxed... you can see each wire is held in place under the black metal clips, just lift each clip up gently and maneuver the wires out, you may want to do this before wiggling the connectors out of the bracket, it will give you a little slack.

My 2005 A8L W12 has over 200K, and she is fine, at 170k or so when I did plugs, coils, injectors, etc, the intake valves looked like new, no build-up.

Side note, I through the larger injectors from one of my Bentley W12 TT break downs into the NA Audi A8L W12, I definitely felt an increase in power, if only by the seat of the pants dyno...

Johnny

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Thank you for the quick reply.

2 new Bosch MAFs ordered, given that the split pieces are hanging off and just over the air inlet that leads to the turbos and engine bowels.
Will give the valve cover thing a try with the tips suggested.

Thought these were direct injection, nice to know its port. As for the carbon thing, I find it a lose/lose. If it's port injected, clean intake valves, but more carbon on piston crowns leading to sludging/sticking piston seals as the carbon melts downward onto them, oil consumption, and eventual rebuild required. If it's direct, piston crowns don't get excessive carbon due to gasoline and additives, but intake valves get carboned up as nothing is flowing over them. Think I'd rather have dirty valves that can be walnut blasted rather than dirty piston seals that soaks usually don't help with either - if I had to pick my poison that is. Ah well.

 

@Johnny Hotspur GT

Removed intake manifold.




Ran into a new problem though. Haven't done spark plugs or anything really as a result.
Issue is, oil in intake tubes from turbo to manifold, oil in manifold casting, oil in intake valve ports, in PCV tubing, etc. Fresh cleanish oil everywhere, same color as dipstick oil.
Intake valves are free of carbon, just coated in oil.
Manifold gasket had unbelievable amount of oil on it and mating surface of manifold, both above and below gasket.
Backs of throttle body plates on intake manifold side have fresh oil on them.
99% chance it's either bad PCVs or it's the existing vacuum leak leading to inability of car to separate oil from air, unless it's normal for these cars.

Here are some pictures, is this amount of oil normal, or representative of vac leaks/bad PCVs?
You can even see the darkish oil puddling at the seams in the valve ports before it hits the ports closer to the valves themselves.
Not sure if I should skip the plugs and put everything back together until I resolve vac leaks as the new spark plugs will probably get fouled from all this oil?

Last week was the first time I ever did spark plugs or valve cover on a car, 3 cylinder mini cooper, this is all a bit new for me.

 

@rsebastien1993 ,
Sorry for the late reply, was working on my B myself..
As to the amount of oil in your intake, I wouldI not worry yourself over it, you do have 250K on her, my naturally aspirated W12 in the Audi had a little less the yours, and I was at 170k or so when I pulled the intake iirc, my audi does use a little oil, nothing major, no smoke, I haven't really noticed any loss on the Bentley, and it did have oil in the intercooler air hoses, and she only had 10,380 miles on her, everyone that has ever talked about the oil in the hoses and intake, says it's the norm, when you pull the spark plugs, you will know if you have an issue.

Johnny

 

No worries, thanks for the reply. Pulling sparks Saturday or Sunday probably. I will know if I have issue because they will be wet with oil?

 

Yes, or fouled badly...


Johnny