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Eurovan Gasoline Fumes when Hot & High - Recap

 

Sorry for the delay - I crawled under the van and got some pictures of the mysterious round black plastic canister that was spitting gas vapor and dripping liquid gas after a grueling climb. ?It's the big round plastic thing on the left. ?You can see where the gas had dripped, it's the little clean bit. ?Fuel hoses go into, and come out of, it. ?

Then there was an extremely hot engine thing immediately in front of it, and (not in the picture) my propane tank was immediately behind it. ?With all the heat and the atomized gasoline, fire danger was certainly a concern.
 

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The round thing is the fuel filter- looks like it has failed!. I think the " box" above it is the charcoal cannister- I replaced mine a few years ago- looks like the same thing. Fuel filters are cheap- just repalce it.


sam


02 EVC

On 9/14/2023 12:59 AM, Goffredo via groups.io wrote:

Sorry for the delay - I crawled under the van and got some pictures of the mysterious round black plastic canister that was spitting gas vapor and dripping liquid gas after a grueling climb. ?It's the big round plastic thing on the left. ?You can see where the gas had dripped, it's the little clean bit. ?Fuel hoses go into, and come out of, it. ?

Then there was an extremely hot engine thing immediately in front of it, and (not in the picture) my propane tank was immediately behind it. ?With all the heat and the atomized gasoline, fire danger was certainly a concern.
 

On Thu, Sep 14, 2023 at 12:31 AM, Goffredo wrote:
mysterious round black plastic canister
I believe that's the air filter, p/n 7D0201849C.? I didn't find one online, but didn't look too hard.? The only reason for gas in it would be overflow from the tank.
--
Duane
05HD Rialta
227K Miles
 

On Thu, Sep 14, 2023 at 05:19 AM, Duane wrote:
On Thu, Sep 14, 2023 at 12:31 AM, Goffredo wrote:
mysterious round black plastic canister
I believe that's the air filter, p/n 7D0201849C.? I didn't find one online, but didn't look too hard.? The only reason for gas in it would be overflow from the tank.

I wanted to post a follow-up in case anyone comes sniffing around here with the same symptoms. ?A few posts back (here?and here with pic) the mysterious round black plastic canister which was spitting gas and fumes in my 2002 EuroVan appears to be the active charcoal evap canister. ?The part number that Duane identifies above is correct and, similar to older EuroVans, is no longer available new.

Please note that this is definitely not a fuel filter, and it's definitely not an air filter. ?It is specifically an active charcoal evap canister - just the new form factor as part of the 2001-2003 model year redesign. ?It would seem that, even though VW re-designed the Evap system for these 2001-2003 model years, they (at least, my) evap canister still suffers from the same problem as the previous design, where liquid gas collects in it during a particular sequence of events (hot temperatures, a recent fill-up, and a huge mountainous ascent). ?

And when such a sequence of events happens, it is most certainly a fire hazard. ?When we pulled over at 9200 feet, it was burbling and hissing and spitting liquid and vapor gas fumes mere inches away from some extremely hot engine components -- certainly hot enough to ignite fuel vapor on contact.

My take-away is to be cognizant of this problem, and on big climbs and in very hot temperatures, periodically check on it (or just give a listen for weird boiling sounds) and plan to give it a few hours to cool off. ?This canister does appear to have a weep hole in the bottom that would allow gravity to extract any liquid gas and so I can only assume it is self-correcting. ?Part of me wants to cut it open and make sure the charcoal hasn't turned to dust, but the other part of me doesn't really feel like dealing with it!
 

On Thu, Jan 18, 2024 at 06:45 PM, Goffredo wrote:
appears to be the active charcoal evap canister
No, the charcoal canister on the 2001 and up is the big rectangular thing behind it in your photo.? One VW source says the round one is "evap canister air cleaner".
--
Duane
05HD Rialta
227K Miles
 

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As Duane points out, that's not quite right.

From??-- ?the round canister (part #12) is the air filter for diagnostic pump.

Here's my understanding of how it works:

Part 9 (the big rectangular part) is the vapor canister.

Part 15 is the Leak Detection Pump (LDP)
It has two functions:?
1. as the vent valve
2. as a vacuum operated pressure pump to check for leaks.?

In normal operation, the LDP is in mode 1, and the vent is open to the atmosphere:
Air can flow into tube 18, through the filter (12), into the LDP (15), through the vent tube (14), into the charcoal canister (9). As air flows in, the stored gasoline vapors come out of the charcoal pellets, and the air+gasoline fume mix is sucked back into the engine via hose 22, through the N80 valve (24) via the hose (25) to the throttle body to be burned off.

The fact that you have liquid gasoline and fumes escaping from part #12 and can hear boiling is consistent with the whole system being overly hot and pressurized.

Since Part #12 is just an air filter and is connected via tube 18 to the grommet #3 (listed as "clipped into the left long member") I do wonder if your #12 is actually clogged. ?That could explain why pressure is escaping there (rather than via tube 18) and also could explain why your pressure is building up in the first place: ? With the N80 open, vapor should be getting pulled out, but to do that part #12 needs to be free-flowing. ?If part 12 is clogged, even with the N80 valve open 100% fumes would be building up in the canister.

Part #12 is interesting. ?This diagram is for a 2001 and later - the 1997-2000 models don't have a filter on the LDP inlet at all. ?
I'm not sure why you need a filter there in the first place? Perhaps it serves to keep dust and grit out of the LDP? ??

If you can't find a new #12, I bet you could bypass #12 temporarily and see if that fixes your gas fume issue.

Mike



PastedGraphic-1.png


On Jan 18, 2024, at 7:18 AM, Goffredo via groups.io <phi-lawn-0t@...> wrote:

On Thu, Sep 14, 2023 at 05:19 AM, Duane wrote:
On Thu, Sep 14, 2023 at 12:31 AM, Goffredo wrote:
mysterious round black plastic canister
I believe that's the air filter, p/n 7D0201849C.? I didn't find one online, but didn't look too hard.? The only reason for gas in it would be overflow from the tank.

I wanted to post a follow-up in case anyone comes sniffing around here with the same symptoms. ?A few posts back (here?and here with pic) the mysterious round black plastic canister which was spitting gas and fumes in my 2002 EuroVan appears to be the active charcoal evap canister. ?The part number that Duane identifies above is correct and, similar to older EuroVans, is no longer available new.

Please note that this is definitely not a fuel filter, and it's definitely not an air filter. ?It is specifically an active charcoal evap canister - just the new form factor as part of the 2001-2003 model year redesign. ?It would seem that, even though VW re-designed the Evap system for these 2001-2003 model years, they (at least, my) evap canister still suffers from the same problem as the previous design, where liquid gas collects in it during a particular sequence of events (hot temperatures, a recent fill-up, and a huge mountainous ascent). ?

And when such a sequence of events happens, it is most certainly a fire hazard. ?When we pulled over at 9200 feet, it was burbling and hissing and spitting liquid and vapor gas fumes mere inches away from some extremely hot engine components -- certainly hot enough to ignite fuel vapor on contact.

My take-away is to be cognizant of this problem, and on big climbs and in very hot temperatures, periodically check on it (or just give a listen for weird boiling sounds) and plan to give it a few hours to cool off. ?This canister does appear to have a weep hole in the bottom that would allow gravity to extract any liquid gas and so I can only assume it is self-correcting. ?Part of me wants to cut it open and make sure the charcoal hasn't turned to dust, but the other part of me doesn't really feel like dealing with it!

 

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Here's another diagram - this one is in schematic form (has a different numbering key), but it shows the same info:

Original from?

I've marked it up to show the normal flow path, and what I think might be wrong with yours:

PastedGraphic-1.png
 

Curious where and how you placed the NAPA Gold 3002 filter. Picked one up yesterday, it looks huge, 2" diameter and 4" long. Up stream of the N80 valve is understood, but where precisely?
 

On Fri, Aug 23, 2024 at 03:27 PM, JallyCamper wrote:
it looks huge, 2" diameter and 4" long. Up stream of the N80 valve is understood, but where precisely?
It basically replaces the hose from the driver end of the N80 to the upright solid line.? The only 'old' hose you need is enough to make the connections.
--
Duane
05HD Rialta
227K Miles
 

Replacement of the N80 purge valve on 1997 EVC 8/24/24

?

Tested the old N80 valve. Applied 12 volts DC, it clicked. I could, by blowing on the input side, get some air to pass, but very little and I had to blow very hard.

?

I replaced the original Bosch 0-280-142-308 valve with an aftermarket URO P/N UR-077133517C. Tested the new N80 valve and could easily blow air through it with 12 volts applied.

?

The N80 is attached to the same support used to support the radiator reservoir, with the use of an additional bracket, a bolt, and a clever rubber fitting that holds and surrounds the valve.

?

?

Replaced the hose from the Intake manifold to the N80 with some Fuel line/PCV/EEC hose 5/16”, part# NBH H176, from NAPA and added hose clamps.

?

Reused the short piece of hose from the input side of the N80 valve. This hose is 3”- 4” long and formed into an “L” shape. It looks to have a part number on it of “VW DE COO 701 201 801 C32 96” This hose runs horizontally towards the driver’s side and then drops down once past the radiator reservoir support. VW even put a slight notch in the support and added a piece of rubber to prevent it from cutting into the hose as it turns downward after passing the radiator reservoir support.

?

?

Attached a NAPA fuel filter part # FIL 3002, using some of the new hose from NAPA and some more hose clamps. The filter “nests” vertically behind the radiator reservoir, and pressed up against the vacuum boost for the breaks. It sits about an inch forward of where the original hose came up to meet the N80 valve, so the rubber on the notch was removed and saved for posterity.

?

?

?

If anyone sees something that looks problematic drop me a line. In the meantime, I will monitor the filter and see if the new, functional N80 valve helps with the fuel vapor issue.

?

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