Valves- carboning up

[ArthurPE]

Glad to hear all is good Mal, however I'm sure ArthurPE will chime in again to claim that any gains you feel are bogus

he said they fixed many things in previous posts...

when he got the car back from Audi he said is was fixed and felt like a new car...they hadn't cleaned the valves, so it would seem the valves had nothing to do with it...

if you believe valve deposits alone resulted in a >40% HP loss, keep on keeping on

it looks like they damaged the coating on the valves by being too agressive/abrasive...I'm not sure I would post this stuff in case you ever need Audi warranty service...

[2manytoys]

Actually there is still some carbon on them, that's what you see.

The car had 263awhp, I was expecting around 300awhp, don't know how you got 40% from that? Anyway, carbon is solely responsible for this loss.

[scaghead]

Actually there is still some carbon on them, that's what you see.

The car had 263awhp, I was expecting around 300awhp, don't know how you got 40% from that? Anyway, carbon is solely responsible for this loss.

glad the car feels better for you, it will be interesting to see what shelia does on the dyno...let us know

[don]

Actually there is still some carbon on them, that's what you see.

The car had 263awhp, I was expecting around 300awhp, don't know how you got 40% from that? Anyway, carbon is solely responsible for this loss.

Perhaps as a result of the carbon buildup the engine management detects the resultant consequences and forces the car to run in limp mode resulting in the additional power losses.

[2manytoys]

The carbon buildup stops the valves from seating correctly. In my case the car started pinging, and ultimately retarded the timing. So a combination of restricted air flow and retarded timing caused a loss of probably 30+awHP, maybe more. I'll know for sure soon though.

[ArthurPE]

timing is adjusted by the following:
1 knock sensors
2 load
3 traction/slippage

1 would set an engine check light
the other 2 are normal operating parameters

no way, no how, will you loose this much power due to deposits...as he indicated himself when he got the car back from Audi and it felt great...and they hadn't cleaned them...
as others have said, based on the curve, something else was 'broken', most likely the intake flaps...which also factor into the deposit prevention scheme(s)

[2manytoys]

No, flaps were/are good and tested again after Manifold was put back in. This is sooooo easy to test too.

Yes, car felt better after Audi but,

The car felt GREAT after the local guy cleaned the valves correctly.

I've got no vested interest in talking this stuff up. Hell, I'm in Australia and most Australian's haven't even heard of an RS4. If I was talking about a V8 Holden Ute, now that's another story. I'm in the IT business, nothing to do with cars, and I'm not getting any payments or kickbacks for my information. It is what it is.

Arthur, you have got to work for Audi, are a Lawyer (want to be one if you are not), or related to Audi in some way or another. What's the go? (Oh, and because I can't show tone, I'm not writting this in an angry way, just curious)

[ArthurPE]

No, flaps were/are good and tested again after Manifold was put back in. This is sooooo easy to test too.

Yes, car felt better after Audi but,

The car felt GREAT after the local guy cleaned the valves correctly.

I've got no vested interest in talking this stuff up. Hell, I'm in Australia and most Australian's haven't even heard of an RS4. If I was talking about a V8 Holden Ute, now that's another story. I'm in the IT business, nothing to do with cars, and I'm not getting any payments or kickbacks for my information. It is what it is.

Arthur, you have got to work for Audi, are a Lawyer (want to be one if you are not), or related to Audi in some way or another. What's the go? (Oh, and because I can't show tone, I'm not writting this in an angry way, just curious)

don't shoot the messanger...
I'm no lawyer, but do consult for them, and I don't work for Audi, they couldn't pay enough

I am a engineer with extensive experience (~30 years) in engine application and trouble shooting, primarily DI used in generator and pump applications...

there is no way deposits alone caused that power loss, despite your assertions...I'm glad it's 'fixed', but I can say with 100% certainty (using YOUR dyno as proof) that there was more at play...

[don]

I think pinging and retarded timing could do it indirectly, the b5 RS4 would lose 50 hp or so when running in limp mode due to sensor issues as a "safety shutdown" issue rather than solely due to the actual problem such as timing or valve issues so as to prevent any potential damage to the engine.

[ArthurPE]

I think pinging and retarded timing could do it indirectly, the b5 RS4 would lose 50 hp or so when running in limp mode due to sensor issues as a "safety shutdown" issue rather than solely due to the actual problem such as timing or valve issues so as to prevent any potential damage to the engine.

yep, and codes are set...this one is down much more than 50 HP, closer to 70+...

but I contend the deposits were a consequence of another system failure (my guess manifold flaps, they are used in the valve cleaning strategy)
the fact that HP is so flat is very similar to others who have had that exact diagnosis...

if it were deposits, ALL cars would have them, and ALL would be down 70+ HP...
I've recently timed mine and it is faster than all magazine tests...

[pippyrips]

I agree with Arthur, there was probably more than just deposits at fault for such a large power loss but don't agree with the notion that oil/carbon build-up happens because of a faulty part/system.

I had my car opened up first at 19k miles. When the inlet manifold was taken off the car there was so much oil inside it litterally dripped over the floor. The car was perfectly 'heathly' and had absolutely no faults with everything working as Audi intended. Caldy's was filthy with only 5k...

I thought the inlet flaps were to allow 'lean burn' mode and help fuel economy as opposed to helping combat deposits but either way they simply can't do anything with that volume of oil present and even if it did it won't help when you turn the engine off - the oil will drip down and bake on to the valves.

[ArthurPE]

I agree with Arthur, there was probably more than just deposits at fault for such a large power loss but don't agree with the notion that oil/carbon build-up happens because of a faulty part/system.

I had my car opened up first at 19k miles. When the inlet manifold was taken off the car there was so much oil inside it litterally dripped over the floor. The car was perfectly 'heathly' and had absolutely no faults with everything working as Audi intended. Caldy's was filthy with only 5k...

I thought the inlet flaps were to allow 'lean burn' mode and help fuel economy as opposed to helping combat deposits but either way they simply can't do anything with that volume of oil present and even if it did it won't help when you turn the engine off - the oil will drip down and bake on to the valves.

I agree, valve deposits are a natural occurance in this engine (and others of similar type), but the deposits are made worse by a failure in a system meant to mitigate them...

the VW/Audi patent states the flaps help redirect exhasut gas to scour the valves, in fact they give the results of a test where the flaps are present and not present, and the deposits actually decrease with the flaps...

http://www.google.com/patents?id=fLITAA ... q=&f=false

read section 12 last para., continued to 13 first para. on...
this is very interesting:
the 'butterfly' valves do negate the formation of deposits...also, they state by moving these in a certain portion of the combustion cycle 'surprisingly' the deposits (limited by the other measures), have "no negative effect on the operational reliabilty or operating behaviour of the internal combustion engine"

this is the crux of the 'invention' being patented, CLOSING the valves when conventional thinking implies they should be open...to clean the valves...

sect. 12
http://www.google.com/patents?id=fLITAA ... 131&edge=0

sect. 13
http://www.google.com/patents?id=fLITAA ... 244&edge=0

[2manytoys]

Guys, I think you are reading my Dyno graph wrong. The car made 263awhp (196awkW). I was expecting about 300awhp, so a loss of somewhere around 40hp I guess?

I think the graph shows how the timing is pulled back, as it's flat from about 6000 rpm.

I wish it was something else that broke, at least I could just replace that if it breaks again.

Anyway, let's leave it at that just for the moment. I'll post up some new Dyno results, and timed runs within the next few days.

Mal.

[ArthurPE]

Guys, I think you are reading my Dyno graph wrong. The car made 263awhp (196awkW). I was expecting about 300awhp, so a loss of somewhere around 40hp I guess?

I think the graph shows how the timing is pulled back, as it's flat from about 6000 rpm.

I wish it was something else that broke, at least I could just replace that if it breaks again.

Anyway, let's leave it at that just for the moment. I'll post up some new Dyno results, and timed runs within the next few days.

Mal.

yes, yours was around 260, most numbers here in the states ~330
that's 70 HP

even with timing retarded the HP would increase, not stay level, since it retards proportionally, not all in one shot...

look at some dyno day threads here, the graphs that look like yours had bad intake flaps...and made ~260 HP

[sonny]

I had my car opened up first at 19k miles. When the inlet manifold was taken off the car there was so much oil inside it litterally dripped over the floor. The car was perfectly 'heathly' and had absolutely no faults with everything working as Audi intended. Caldy's was filthy with only 5k...

Question, why did these 2 cars look so different, do you think ECU software updates plays a role the build up of carbon? like one car still running the original SW and one has the latest update, or if not, do you think it it will mitigate it.