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Audi 's Alusil 4.2 Engine Rebuild Resources part 1

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#22 ·
Thats a gorgeous S8! I've never seen one in that colour before. I love the interior combo too.

What causes the engines to fail like this? My 3.7 40V A8 had 185K on it when the autobox died, but the engine was still running perfectly. It used a litre of oil per 1000 miles consistently from 85K when I bought it to the day I sold it.
 
#23 ·
MikkiJayne said:
Thats a gorgeous S8! I've never seen one in that colour before. I love the interior combo too.

What causes the engines to fail like this? My 3.7 40V A8 had 185K on it when the autobox died, but the engine was still running perfectly. It used a litre of oil per 1000 miles consistently from 85K when I bought it to the day I sold it.
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Bore scoring is what causes the oil consumption problem, and things get worse from there on in. It seems that the bore scoring has several causes, but the main one seems to be oil /gas dilution from not changing oil frequently enough. Audi's recommended oil change interval is too long by a factor of 4 it seems. Rings sticking in thier grooves from carbon build up also seems to be a major cause, and lastly in the BHF motors there is a design flaw of sorts whereby the top compresion ring is too thin and too close to the crown cutout.
 
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#24 ·
Wow I guess I was just lucky then, since my A8 ran with 18k oil changes.

Audis daft oil changes have destroyed a considerable number of V6 TDIs as well. They eat their own camshafts with 18k changes!

Luckily I know better now and change the gassers at 10k and the diesels at 5. It's something to watch out for when I buy another A8 tho. Boroscope in the engine as well as sampling the trans oil...
 
#25 ·
I have never seen any Audi audi motor fail that wasnt either the owners fault or audi had a bad run of motors. If you're not using synthetic you're screwing yourself. I have seen many sludged out Audi motors that lost the nicasil and mostly in V8's. The only Audi motors I have seen fail with synthetic are 4.2 FSI motors, some FSI non-v8's and they all failed within 5000 miles of date of purchace. I do think it's stupid to coat the cylinder walls with nicasil because there are a lot of variables that can affect the nicasil but I have seen many high mileage 4.2's running just fine and I would say all of the ones I have seen are dealer queens who always get oil changes with synthetic and always maintained.
 
#26 ·
quattrocrazy said:
I have never seen any Audi audi motor fail that wasnt either the owners fault or audi had a bad run of motors. If you're not using synthetic you're screwing yourself. I have seen many sludged out Audi motors that lost the nicasil and mostly in V8's. The only Audi motors I have seen fail with synthetic are 4.2 FSI motors, some FSI non-v8's and they all failed within 5000 miles of date of purchace. I do think it's stupid to coat the cylinder walls with nicasil because there are a lot of variables that can affect the nicasil but I have seen many high mileage 4.2's running just fine and I would say all of the ones I have seen are dealer queens who always get oil changes with synthetic and always maintained.
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LOL no offense but you have no clue.

Audi don't even use Nikasil and I have seen many V8's fail, they all score their bores, it's just a matter of time, not if, when.
 
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#27 ·
Sorry Alusil... picking the fly shit out of the pepper. Pistons and rings don't just score bores. you're getting a lot of coking from not using synthetic and actually listening to audi and their 10,000mi oil changes or using shitty gas and getting failures. New Audis have always had a carbon issue and I have done more decarbs than I care to remember. I would say it's more of a shitty fuel, extended oil change intervals, and crap PCV system problem. Not to mention the amount of leaky injectors I have found or loose intake manifolds sucking shit in from the valley or running the engine lean. How about everytime you scan for codes you see fuel trim lean? Why? Because the carbon is absorbing the fuel. There are so many reasons why V8's fail and I wouldn't say it's all due to alusil but a combination of alusil and poor maintenance or manufacturing.
 
#28 ·
quattrocrazy said:
How about everytime you scan for codes you see fuel trim lean? Why? Because the carbon is absorbing the fuel.
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So the fuel runs out of the combustion chamber (where it get's injected on the new motors with carbon issues), through a closed valve, so it can spend some time with all the other fuel in the carbon black hole that doesn't ever fill up with fuel, causing this lean code?
 
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#33 ·
quattrocrazy said:
And by new Audis I mean new body style audi A models. How are you going to get carbon in a new engine? Come on really?
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Perhaps a google for "RS4 Carbon" will refresh you on the new engine carbon issues. Really!
 
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#34 ·
wow, you sure one upped me... Since I haven't worked in a dealer since the RS4 came out and I don't own one why would it matter to me? If you work on Audis or ever read SSP's you would already know that the valve timing is also one of the major factors in the whole carbon fiasco. You recirculate exhaust gasses you get carbon. Doesn't take a genius. So asking me sarcastically the answer to the question you should already know either makes you look stupid or douchy. It's funny how people representing a complany I buy parts from act so unprofessional.

The facts are Audi has NEVER thought of a good way to get oil vapor out of the crankcase and this is even more evident when you get into turbo cars like the 2.7t and it's extra oil tanks. I mean intercoolers... Audi has NEVER addressed the fact that their PCV system is always made out of plastic or rubber that fails and if it is made out of metal they put it under the intake manifold... Audi has NEVER addressed the fact that their cars sludge oil and leak badly from cam seals you replace every year with vave cover gasket that seem to be getting pressureized. Audi has NEVER addressed the issue of having the PCV passages going thru the head to the combi valves that get clogged along with the head not to mention the combi valves are vacuum controlled and the solenoids fail or the vacuum lines collapse.These factors are too big to ignore to blame it all on a coating. Using good quality synthetic with 5000 mile oil changes I have noticed cuts down on a lot of everyday audi issues.
 
#37 ·
the bores are only one piece of the puzzle. what rings are people using, and what pistons are people using with alusil? really, i am more interested in a low compression, custom piston alternative for turbo aps.
 
#38 ·
FYI, mahle coats their pistons with a graphite coating that is suppose to eliminate the need for recoating. You simply use standard boring techniques and run their pistons as you would with iron bores.
 
#40 ·
According to the former owner of Bertil's Racing Engines. They used to make VW F3 engines. I
It is possible to sleeve the V8 blocks.
He knows a company that can do it, and It is not as much as most people would think.
The machine work on the block is whats going to be expensive.
 
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