Fuel Pumps
Re: Fuel Pumps
It sounds like a failure there would give you more obvious symptoms. They all stated brake servo problems when it failed. Eliminate the easy options first, I guess.
Daytona RS6 C5 Avant. Viper'd, Billies, Waggers, MTM box brain, C6 stoppers, xcarlink, R8 coolant cap (woohoo)
///M3 E46 | XC90 (V8, natch) | Passat GTE | RR Classic V8 flapper
"The major difference between a thing that might go wrong and a thing that cannot possibly go wrong is that when a thing that cannot possibly go wrong goes wrong it usually turns out to be impossible to get at and repair."
///M3 E46 | XC90 (V8, natch) | Passat GTE | RR Classic V8 flapper
"The major difference between a thing that might go wrong and a thing that cannot possibly go wrong is that when a thing that cannot possibly go wrong goes wrong it usually turns out to be impossible to get at and repair."
Re: Fuel Pumps
Actually trying to identify all possible causes was more an opportunity to educate myself, but at the same time you're getting paranoid and you end up believing your car suffer from all possible diseases!
But yeah, back to the main suspects.
But yeah, back to the main suspects.
RS6 C5 Avant 2003 Daytona Grey
Loba 650 turbos - Wagner IC - 200 cells cats - Milltek cat-back - Hotchkis bars - Bilstein B16 - MTM Wheels - oem coolant cap
Loba 650 turbos - Wagner IC - 200 cells cats - Milltek cat-back - Hotchkis bars - Bilstein B16 - MTM Wheels - oem coolant cap
Re: Fuel Pumps
I think the N80 vac circuit could benefit from further investigation, especially where it connects back into the manifold and turbos:
Those non-return valves have been known to fail, too.
Those non-return valves have been known to fail, too.
Daytona RS6 C5 Avant. Viper'd, Billies, Waggers, MTM box brain, C6 stoppers, xcarlink, R8 coolant cap (woohoo)
///M3 E46 | XC90 (V8, natch) | Passat GTE | RR Classic V8 flapper
"The major difference between a thing that might go wrong and a thing that cannot possibly go wrong is that when a thing that cannot possibly go wrong goes wrong it usually turns out to be impossible to get at and repair."
///M3 E46 | XC90 (V8, natch) | Passat GTE | RR Classic V8 flapper
"The major difference between a thing that might go wrong and a thing that cannot possibly go wrong is that when a thing that cannot possibly go wrong goes wrong it usually turns out to be impossible to get at and repair."
Re: Fuel Pumps
Might be worth going to Audi (or VW, Skoda, etc.) and getting some leak detector spray (G 001 800 A1). That way you can spray it in select places around the engine and try to narrow down the area of the leak.
Daytona RS6 C5 Avant. Viper'd, Billies, Waggers, MTM box brain, C6 stoppers, xcarlink, R8 coolant cap (woohoo)
///M3 E46 | XC90 (V8, natch) | Passat GTE | RR Classic V8 flapper
"The major difference between a thing that might go wrong and a thing that cannot possibly go wrong is that when a thing that cannot possibly go wrong goes wrong it usually turns out to be impossible to get at and repair."
///M3 E46 | XC90 (V8, natch) | Passat GTE | RR Classic V8 flapper
"The major difference between a thing that might go wrong and a thing that cannot possibly go wrong is that when a thing that cannot possibly go wrong goes wrong it usually turns out to be impossible to get at and repair."
Re: Fuel Pumps
I think you're really onto something particularly relevant Shoppinit, let me substanciate that further down. But before going to the point I'd like to report a few things:
I've done some more tests this morning, first one being the 'sucking test' for those SAI valves. So I disconnected those hoses and tried to suck air, and the result is that they keep the vaccum fine (both sides), as well as pressure. What I'm trying to say is that air is blocked both ways whether blowing or sucking (with the mouth
). For that matters, I can clearly hear the 'plop' sound of a membrane moving inside the valves on the right side of the engine (Bank 2), however it's less distinct on the left side (Bank 1). As a reminder I have less metered air going to Bank 1 compared to Bank 2.
Second test I did was to log MAFs reading from cold start, and I can now definetely say for sure the discrepancies between banks only appear when engine is hot (coolant at 90°C), which on this cold morning in Paris took like 7 minutes or so, SAI was already stopped for a long time (like a minute or so after engine cold start).
Now coming back to your suggestions Shopp: I was moving around the engine trying to locate a possible hiss, when I heard a solenoid clicking like mad on the left side of the engine. I took note of the ETKA ref (077 133 517C) and realized it's the damned N80 you already mentionned quite a few times! To be precise, it seems to click constantly for like 10-20s then stop, then click again... Next question of course is whether the valve itself is faulty or something upstream/downstream is causing this, but looks like your intuition was spot on, I'm impressed (as if it wasn't the case before...).
How shall we take it from there?
I've done some more tests this morning, first one being the 'sucking test' for those SAI valves. So I disconnected those hoses and tried to suck air, and the result is that they keep the vaccum fine (both sides), as well as pressure. What I'm trying to say is that air is blocked both ways whether blowing or sucking (with the mouth
). For that matters, I can clearly hear the 'plop' sound of a membrane moving inside the valves on the right side of the engine (Bank 2), however it's less distinct on the left side (Bank 1). As a reminder I have less metered air going to Bank 1 compared to Bank 2.Second test I did was to log MAFs reading from cold start, and I can now definetely say for sure the discrepancies between banks only appear when engine is hot (coolant at 90°C), which on this cold morning in Paris took like 7 minutes or so, SAI was already stopped for a long time (like a minute or so after engine cold start).
Now coming back to your suggestions Shopp: I was moving around the engine trying to locate a possible hiss, when I heard a solenoid clicking like mad on the left side of the engine. I took note of the ETKA ref (077 133 517C) and realized it's the damned N80 you already mentionned quite a few times! To be precise, it seems to click constantly for like 10-20s then stop, then click again... Next question of course is whether the valve itself is faulty or something upstream/downstream is causing this, but looks like your intuition was spot on, I'm impressed (as if it wasn't the case before...
).How shall we take it from there?
RS6 C5 Avant 2003 Daytona Grey
Loba 650 turbos - Wagner IC - 200 cells cats - Milltek cat-back - Hotchkis bars - Bilstein B16 - MTM Wheels - oem coolant cap
Loba 650 turbos - Wagner IC - 200 cells cats - Milltek cat-back - Hotchkis bars - Bilstein B16 - MTM Wheels - oem coolant cap
Re: Fuel Pumps
First level of inspection showed no signs of degradation : hoses (namely parts 32-30-24) are fine up to the metallic pipe which goes underneath the manifolds , along with their clamps.
Meanwhile I've checked prices for the solenoid, we're talking about 30€ for the Bosch equivalent (0 280 142 308), well worth trying to change it and see how it goes.
Crossing fingers this won't lead to taking out the manifolds..
Meanwhile I've checked prices for the solenoid, we're talking about 30€ for the Bosch equivalent (0 280 142 308), well worth trying to change it and see how it goes.
Crossing fingers this won't lead to taking out the manifolds..
RS6 C5 Avant 2003 Daytona Grey
Loba 650 turbos - Wagner IC - 200 cells cats - Milltek cat-back - Hotchkis bars - Bilstein B16 - MTM Wheels - oem coolant cap
Loba 650 turbos - Wagner IC - 200 cells cats - Milltek cat-back - Hotchkis bars - Bilstein B16 - MTM Wheels - oem coolant cap
Re: Fuel Pumps
Have you tried sucking on hose 32?
Daytona RS6 C5 Avant. Viper'd, Billies, Waggers, MTM box brain, C6 stoppers, xcarlink, R8 coolant cap (woohoo)
///M3 E46 | XC90 (V8, natch) | Passat GTE | RR Classic V8 flapper
"The major difference between a thing that might go wrong and a thing that cannot possibly go wrong is that when a thing that cannot possibly go wrong goes wrong it usually turns out to be impossible to get at and repair."
///M3 E46 | XC90 (V8, natch) | Passat GTE | RR Classic V8 flapper
"The major difference between a thing that might go wrong and a thing that cannot possibly go wrong is that when a thing that cannot possibly go wrong goes wrong it usually turns out to be impossible to get at and repair."
Re: Fuel Pumps
Not yet, will do!
RS6 C5 Avant 2003 Daytona Grey
Loba 650 turbos - Wagner IC - 200 cells cats - Milltek cat-back - Hotchkis bars - Bilstein B16 - MTM Wheels - oem coolant cap
Loba 650 turbos - Wagner IC - 200 cells cats - Milltek cat-back - Hotchkis bars - Bilstein B16 - MTM Wheels - oem coolant cap
Re: Fuel Pumps
So the car is back from my mechanic with a new timing belt kit, new thermostat & water pump, and a new secondary fan, all OEM except the fan.
Let's start with the good news: I have no more secondary fan controller fault codes! the fan was the culprit. Now I can activate it from the VCDS (output test), and I can see it spinning when the engine is getting hot. That's one thing sorted!
Now regarding the other issues:
- Excessive coolant temperature: unfortunately no change on this front, it still reads at 98°C nominal, and I can see the secondary fan is triggered when coolant temp goes above 99-100°C. I didn't reach the point where the primary fan was triggered, so can't comment on that. My mechanic says I shouldn't worry as some engines run at higher temperature than the 90°C target (is that the target for the BCY?), and the fact that the secondary fan starts spinning at 99-100°C should be an indication that the car has been setup that way. Shall I call it a day or you guys still believe it's still too high? In such case, shall I consider some ECU programming using the VCDS to decrease the target coolant temperature (like you can tune the idle engine speed)?
- Air leak: I'm loosing my mind on this one as my MAFs still show discrepancies between left and right banks at all speeds (remember: only when engine is hot, no issues at lower temperature ie <90°). I now have the air leak kit but to cut a long story short I can't inject more than 5 PSI of air into the system. Results are that the engine seems to hold the (admittedly small) pressure well as it takes like 2 minutes or so to go from 5 to 2 PSI. I suppose I can't make definite conclusions without injecting more pressure, but would you agree when the engine is idle it shouldn't generate more than 5 PSI of depression? Also it may be the case that the engine holds positive pressure well but fails when a depression is applied. So I need to find a pump that could either generate positive AND negative pressure. Any recommandation is appreciated! EDIT: found this https://www.amazon.fr/MVPower-Purge-tes ... ay&sr=8-47 Good to go?
As always, many thanks for your insight & comments!
Let's start with the good news: I have no more secondary fan controller fault codes! the fan was the culprit. Now I can activate it from the VCDS (output test), and I can see it spinning when the engine is getting hot. That's one thing sorted!
Now regarding the other issues:
- Excessive coolant temperature: unfortunately no change on this front, it still reads at 98°C nominal, and I can see the secondary fan is triggered when coolant temp goes above 99-100°C. I didn't reach the point where the primary fan was triggered, so can't comment on that. My mechanic says I shouldn't worry as some engines run at higher temperature than the 90°C target (is that the target for the BCY?), and the fact that the secondary fan starts spinning at 99-100°C should be an indication that the car has been setup that way. Shall I call it a day or you guys still believe it's still too high? In such case, shall I consider some ECU programming using the VCDS to decrease the target coolant temperature (like you can tune the idle engine speed)?
- Air leak: I'm loosing my mind on this one as my MAFs still show discrepancies between left and right banks at all speeds (remember: only when engine is hot, no issues at lower temperature ie <90°). I now have the air leak kit but to cut a long story short I can't inject more than 5 PSI of air into the system. Results are that the engine seems to hold the (admittedly small) pressure well as it takes like 2 minutes or so to go from 5 to 2 PSI. I suppose I can't make definite conclusions without injecting more pressure, but would you agree when the engine is idle it shouldn't generate more than 5 PSI of depression? Also it may be the case that the engine holds positive pressure well but fails when a depression is applied. So I need to find a pump that could either generate positive AND negative pressure. Any recommandation is appreciated! EDIT: found this https://www.amazon.fr/MVPower-Purge-tes ... ay&sr=8-47 Good to go?
As always, many thanks for your insight & comments!
Last edited by Classik on Thu Apr 18, 2019 12:31 pm, edited 6 times in total.
RS6 C5 Avant 2003 Daytona Grey
Loba 650 turbos - Wagner IC - 200 cells cats - Milltek cat-back - Hotchkis bars - Bilstein B16 - MTM Wheels - oem coolant cap
Loba 650 turbos - Wagner IC - 200 cells cats - Milltek cat-back - Hotchkis bars - Bilstein B16 - MTM Wheels - oem coolant cap
Re: Fuel Pumps
Oh and I did suck on hose 32: when the sucking is small air is passing without resistance, but when sucking is harder - 
can't say it better with my poor English- some valve must be triggered as air is blocked and vaccum is corrected kept.
can't say it better with my poor English- some valve must be triggered as air is blocked and vaccum is corrected kept.RS6 C5 Avant 2003 Daytona Grey
Loba 650 turbos - Wagner IC - 200 cells cats - Milltek cat-back - Hotchkis bars - Bilstein B16 - MTM Wheels - oem coolant cap
Loba 650 turbos - Wagner IC - 200 cells cats - Milltek cat-back - Hotchkis bars - Bilstein B16 - MTM Wheels - oem coolant cap
Re: Fuel Pumps
Forgot to say, I have also changed the N80 valve. At least it doesn't click like mad anymore and tested OK with the VCDS. Same results on the MAFs readings though... 
RS6 C5 Avant 2003 Daytona Grey
Loba 650 turbos - Wagner IC - 200 cells cats - Milltek cat-back - Hotchkis bars - Bilstein B16 - MTM Wheels - oem coolant cap
Loba 650 turbos - Wagner IC - 200 cells cats - Milltek cat-back - Hotchkis bars - Bilstein B16 - MTM Wheels - oem coolant cap
Re: Fuel Pumps
Why can you only put 5 psi in?
Daytona RS6 C5 Avant. Viper'd, Billies, Waggers, MTM box brain, C6 stoppers, xcarlink, R8 coolant cap (woohoo)
///M3 E46 | XC90 (V8, natch) | Passat GTE | RR Classic V8 flapper
"The major difference between a thing that might go wrong and a thing that cannot possibly go wrong is that when a thing that cannot possibly go wrong goes wrong it usually turns out to be impossible to get at and repair."
///M3 E46 | XC90 (V8, natch) | Passat GTE | RR Classic V8 flapper
"The major difference between a thing that might go wrong and a thing that cannot possibly go wrong is that when a thing that cannot possibly go wrong goes wrong it usually turns out to be impossible to get at and repair."
Re: Fuel Pumps
I'll take mine out tomorrow and measure the temps. That way we can at least compare mine to yours. Should be quite a warm day so it will be interesting to see what happens.Classik wrote: ↑Thu Apr 18, 2019 11:53 am- Excessive coolant temperature: unfortunately no change on this front, it still reads at 98°C nominal, and I can see the secondary fan is triggered when coolant temp goes above 99-100°C. I didn't reach the point where the primary fan was triggered, so can't comment on that. My mechanic says I shouldn't worry as some engines run at higher temperature than the 90°C target (is that the target for the BCY?), and the fact that the secondary fan starts spinning at 99-100°C should be an indication that the car has been setup that way. Shall I call it a day or you guys still believe it's still too high? In such case, shall I consider some ECU programming using the VCDS to decrease the target coolant temperature (like you can tune the idle engine speed)?
Daytona RS6 C5 Avant. Viper'd, Billies, Waggers, MTM box brain, C6 stoppers, xcarlink, R8 coolant cap (woohoo)
///M3 E46 | XC90 (V8, natch) | Passat GTE | RR Classic V8 flapper
"The major difference between a thing that might go wrong and a thing that cannot possibly go wrong is that when a thing that cannot possibly go wrong goes wrong it usually turns out to be impossible to get at and repair."
///M3 E46 | XC90 (V8, natch) | Passat GTE | RR Classic V8 flapper
"The major difference between a thing that might go wrong and a thing that cannot possibly go wrong is that when a thing that cannot possibly go wrong goes wrong it usually turns out to be impossible to get at and repair."
Re: Fuel Pumps
Because I don't have the correct adaptor between my tyre pump and the air leak kit! So it's just a piece of hose with clamps which leaks above 5 psi... Yeah, it's that stupid..
RS6 C5 Avant 2003 Daytona Grey
Loba 650 turbos - Wagner IC - 200 cells cats - Milltek cat-back - Hotchkis bars - Bilstein B16 - MTM Wheels - oem coolant cap
Loba 650 turbos - Wagner IC - 200 cells cats - Milltek cat-back - Hotchkis bars - Bilstein B16 - MTM Wheels - oem coolant cap
Re: Fuel Pumps
I look forward to your findings, but nevertheless the engine is hot enough to interrupt the aircon.. 
RS6 C5 Avant 2003 Daytona Grey
Loba 650 turbos - Wagner IC - 200 cells cats - Milltek cat-back - Hotchkis bars - Bilstein B16 - MTM Wheels - oem coolant cap
Loba 650 turbos - Wagner IC - 200 cells cats - Milltek cat-back - Hotchkis bars - Bilstein B16 - MTM Wheels - oem coolant cap
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