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Hello Fellow Bentley Enthusiasts,
I have been getting a CEL which codes out to a small evap emissions leak. I have changed the purge solenoid, replaced the gas cap and performed a smoke test with negative results. I don't want to just throw expensive parts like a charcoal cannister at the car without isolating the issue. Its a 2008 Flying Spur with 35K miles. The driving performance seems unaffected, but that little engine symbol drives me insane. Should I resort to service at Bentley or shoot myself first? Thanks for your collective wisdom.
Possibilities: double-check everything and visibly check and if need be: re-smoke test the evap system from the front right inner wheel well where the line goes rearward to the EVAP system and exhaust flaps. Check the rubber vacuum lines going to each vacuum reservoir at each exhaust valve flap. Re-check for vacuum leak at the gas tank (fuel cap, etc.), charcoal canister shut-off valve at the rear of car above the rear plastic undershield, hose leak between the fuel tank / charcoal canister. Vacuum leak between the purge valve and intake manifold hose.
Last edited by 1eapplebaum; Nov 23, 2021 at 01:58 PM.
Hello,
Related question.. had a slight rattle from the exhaust flap valve when cold (only, some 30 sec)..some call it a butterfly valve (?). The Indy suggested to simply disconnect the vacuum hose and blocked it with bolts. However, that changed the entire sound note inside and out, so I had him reconnect them. But, since that, the sound notes remain changed and not for the better. Also, under acceleration there is no more audible vacuum "sound". So, could the disconnect & blocking vacuum hose have damaged something along the lines.. i.e. why were the previous sound notes restored upon reconnect (after just one day)? Any ideas? Thanks !
Hello,
Related question.. had a slight rattle from the exhaust flap valve when cold (only, some 30 sec)..some call it a butterfly valve (?). The Indy suggested to simply disconnect the vacuum hose and blocked it with bolts. However, that changed the entire sound note inside and out, so I had him reconnect them. But, since that, the sound notes remain changed and not for the better. Also, under acceleration there is no more audible vacuum "sound". So, could the disconnect & blocking vacuum hose have damaged something along the lines.. i.e. why were the previous sound notes restored upon reconnect (after just one day)? Any ideas? Thanks !
Thanks Dark Green, that makes a lot of sense. Before messing with it, I only had a slight "rattle" for those 30 sec approx, from the RH tailpipe. Then the Indy took off the vacuum hoses and plugged them. The noise, and vibration in the exhaust when "braking" on engine, was no good, so he put the pipes back. But, the sound note didn't recover.
1eapplebaum: What I described as "vacuum noise" is probably the opening of the valve.. with window down one could hear a short "tsjj" sound.. on my car it was audible under hard acceleration from near standstill, such as joining traffic from a layby.. Quote DarkGreen: "Obviously during subsequent driving, if the speed/transmission/throttle threshold is reached then the solenoids are closed and the valves are released (i.e. opened)".
So I just took a look, and it is a little strange .. On the 2006 W12 only the inner exhaust pipe has a visible valve (dual/single exhaust). So, both sides were open when parked (as presumably they should). Upon starting the car, the RH one closed immediately and rattled a little, which I now see is due to the butterfly not closing fully..a small gap is left open and hence the valve rattles inside the pipe (why would that be...vacuum "management"?), whilst the LH one remained open (not so good). BTW both valves move similarly with manipulation. So waited a minute and then revved the engine .. the RH one opened up..the LH remained open.. no more rattle (since the almost-closed butterfly no longer vibrates in the pipe).. So, does it look like a malfunction on the LH side (which doesn't close on startup), whilst the RH close (immediately, no 30 sec delay, but not fully closed, and so rattles a little) on start-up. And, is there an easy fix for the rattle from the (almost but not quite closed) butterfly.. Bentley says live with it, and when driving it stops.. And if the vacuum hose/pipe has been compromised, is there a usual suspects location to start at.. What of the vacuum solenoids, could it be that one isn't working.. Which are they.. Sorry, I have not messed with this car much..
Presumably, disconnecting (and plugging) the vacuum hose would leave the butterflies open i.e. always on dual exhaust. But under active driving, why would this change the sound notes? Would the butterflies close under driving, when easing up on the accelerator (which is when the changed sound note is most noticeable and annoying). And, would there be any concerns re always being on dual exhaust or plugging disconnected vacuum hoses (other than the less attractive sound note)? Thanks !
Last edited by Lars_Tempest; Dec 1, 2021 at 10:42 AM.
DarkGreen This is really helpful. Luckily, the undertray should come off, had it off not that long ago when checking airlines to suspension (one was gnawed through from touching a bolt - great assembly Crewe..).
So a couple of these might do the trick..how to select a good enough product? Would you know who makes the OEM version?
Hello,
Turns out that my small evap leak in my 2008 Flying Spur is being caused by a ruptured line connected to the rear of the intake manifold on the passenger side of the car (see attached photo of valve and braided line). Does anyone know that part number of this valve and line? Thanks for your help.
Thank you Dark Green,
I have tried to delete my latest thread to avoid duplication. The vacuum line in my car is stamped with 3W1612041T, but the part you listed as 3W1612041R looks more like the one I need. Scuderia was not too helpful and wasn't sure which is the braided line that is connected to the rear of my intake manifold. Their diagrams do not show any views of the rear of the intake manifold with hose connections displayed (at least none that I could find). I will call them again tomorrow to try to sort this out. I would hate to wait weeks for the wrong part. I'm tempted to try to fashion my own line from metal, but I believe that the black fitting is some type of check valve which I would have to retain.
Hello All,
Today I spent several hours trying to remove the defective passenger side check valve and vacuum line that runs from the back of the intake manifold to the firewall. I removed both shields under the car and the passenger side wheel well. There was just no way that I can figure out to access the lower portion of this line while the engine is in place. If there is, it must still involve a huge amount of labor which may be beyond my skill set and is definitely beyond my patience. I can deal with spending money for legitimate maintenance items, but it would gall me to spend several thousand dollars in parts and labor to replace some plastic crap pipes that Bentley was too cheap to engineer from metal for an extra $10.00 It might be time to cut my losses and buy a new ride. The shame of it is that I truly love driving this car, but life is too short for this aggravation. It seems that many of the people on this forum have vastly more mechanical expertise than I do. I'm merely an educated amateur with a lot of basic tools. Kudos to those of you have the ability or deep pockets to rectify Bentley's engineering shortfalls.
May I ask if instead of trying to replace either or the two large plastic lines, did you first try to seal up the end of the line at the check valve at the intake manifold, as the lines rarely fail anywhere in the middle, just the ends, you can see the lines and their layout in my video, of course I pulled my engine out during my GT rebuild, so easily accessible, others have pulled the steering rack to access and repair/replace lines, but those lines are usually the smaller lines, I do recall someone going in with a sealant on a stick to smear around the large lines, as they are vacuum/suction, so no pressure to blow sealant out, kind of a crude repair, but if it saved a $4800 engine out bill, some would do it.
But I would first check for cracks at the top and use some high temperature tape around the line at the check valve, then slide the braided sleeve up and tape that also, see my picture.
Dear Mr. Hotspur,
Unfortunately for me, my vacuum line was not split on top of the engine where I could reach it, or anywhere else along the line that I could reach. The split must be at the lower end which I cannot access.
Dear Mr. Hotspur,
Unfortunately for me, my vacuum line was not split on top of the engine where I could reach it, or anywhere else along the line that I could reach. The split must be at the lower end which I cannot access.
When you did the smoke test, did you check everything at the rear of the vehicle with the belly pan removed, or the lines at each fender well with the wheel well liners removed ?
I did the smoke test as per the Jason Gianetti video in the main line by the driver's side wheel well. I did not remove the pan where the charcoal cannister is. A mechanic diagnosed the leak with a stethoscope
Johnny Hotspur GT hi my question is
I have found the leak when I remove the two big pipes off my intake manifold and cover all holes my leak stops . So my question is can I just block / delete this system ? I understand my brake assist is linked into this . So if I join that with a one way vales to my intake manifold and block everything else . Will this temporarily fix my small leak down on the bulkhead .
Last edited by tony wood; May 20, 2023 at 04:07 AM.
