Carbon Cannister / Purge Valve Removal
Discussion
On my 98 450 this assembly is under the front headlight. Sadly I need to have a look at this as I have a dead car with a fault code 88 so does anybody know how it comes out? I read some where about "starting with the carbon can and building a car around it" They weren't joking!
Maybe the valve comes off and can be examined separately?
Cheers
Maybe the valve comes off and can be examined separately?
Cheers
Worst case the valve is iopen when it should be closed, just squash the hose into the trumpet base flat to block it. If the problem (whatever it is; you don't say) goes away then you know it is something to do with the purge valve. More likely imo you'll find it doesn't make a blind bit of difference, and if you have a dead car you're better off diagnosing the problem from first principles. Does the engine turn over; do you have fuel; do you have a spark?
Edited by GreenV8S on Wednesday 13th June 17:58
What I think Peter is trying to emphasise is that if you have a fault(s) the ECU should go into limp home mode. It should not be 'dead' - just not fully alive - but startable & driveable 
Some of the cans are just slotted in - lifting them upwards allows them to be removed from the mount (you need to disconnect a few hoses & the electrical connector before they can be extracted tho).
Dave
Some of the cans are just slotted in - lifting them upwards allows them to be removed from the mount (you need to disconnect a few hoses & the electrical connector before they can be extracted tho).
Dave
Code 88 is a self test code - this is not the cause of your problem.
Check if there is another code under it by unplugging the reader while the car is running and reconnecting it after 5 seconds. Then switch off the engine, wait until you hear the ECU relay drop out (about 5 seconds) and then restart. If there is another fault code it will be displayed.
PM me if you need anymore help.
Check if there is another code under it by unplugging the reader while the car is running and reconnecting it after 5 seconds. Then switch off the engine, wait until you hear the ECU relay drop out (about 5 seconds) and then restart. If there is another fault code it will be displayed.
PM me if you need anymore help.
A bit of background. Car was fine then a week back it cut out at the lights. Restarted but not happy. Back up to speed it was fine. Same thing happened once more that day but not at every set of lights. Gradually got worse until this morning it ran like a three legged camel for 20 secs then nothing. Fortunately my BITS_FC1 code reader arrived so I got the 88 code which according to the bible and the FC1 instructions can be nothing or the purge valve on a cat car.
Clamped the hose to the plenum and off she goes! Switched off, unclamped and idles fine? Reset ECU, fired up fine, no errors. No chance for a run so we will see tomorrow if the error reappears when it purges.
Interestingly she has always whistled on the overun above 2k revs so I knew I had an air leak somewhere, so now I think I've found it!?
Clamped the hose to the plenum and off she goes! Switched off, unclamped and idles fine? Reset ECU, fired up fine, no errors. No chance for a run so we will see tomorrow if the error reappears when it purges.
Interestingly she has always whistled on the overun above 2k revs so I knew I had an air leak somewhere, so now I think I've found it!?
Coming a bit late to this and slightly off-topic, but....
TPO you say yours always used to whistle on the overrun? Mine also does this! I thought I had cured it a year or so ago but its recently come back. The whistling stops as the revs drop around 2K and doesn't happen at all under load. Interestingly, on mine it won't START whistling until the engine temp reaches 60/70 - is this the same as yours?
So its the carbon cannister that causes this? Or the pipework from the engine? Its difficult to tell with everything running but mine appears to originate from around the PAS reservoir.
I know the 'reason' for the cannister and purge valve being there - can it not just be done away with and vent straight to atmosphere?
As an aside, the purge valve on my girlfriends VW Lupo failed a while ago, caused her car to cut out at pretty much every junction - replacement from VW? About 70 quid!
Cheers
Mark
TPO you say yours always used to whistle on the overrun? Mine also does this! I thought I had cured it a year or so ago but its recently come back. The whistling stops as the revs drop around 2K and doesn't happen at all under load. Interestingly, on mine it won't START whistling until the engine temp reaches 60/70 - is this the same as yours?
So its the carbon cannister that causes this? Or the pipework from the engine? Its difficult to tell with everything running but mine appears to originate from around the PAS reservoir.
I know the 'reason' for the cannister and purge valve being there - can it not just be done away with and vent straight to atmosphere?
As an aside, the purge valve on my girlfriends VW Lupo failed a while ago, caused her car to cut out at pretty much every junction - replacement from VW? About 70 quid!
Cheers
Mark
If you dont 'purge' the carbon can at all, you will end up with the very smelly front wing syndrome & eventually petrol clogging the can and dripping into the undertray. If you block the vent pipe to the tank - the fuel pump will create a vacuum in the tank.
I replaced mine with one from a common rover 200/400 (fiver @ scrappy) which as far as I could see was identical to unit on my LR (seemed the same as used on TVR). I did this because mine had the much earlier separate purge valve rather than the nicer packaging of the later integral unit.
Dave
I replaced mine with one from a common rover 200/400 (fiver @ scrappy) which as far as I could see was identical to unit on my LR (seemed the same as used on TVR). I did this because mine had the much earlier separate purge valve rather than the nicer packaging of the later integral unit.
Dave
Trevor,
Last time it happened I happened to notice that I was slightly down on coolant, as it stopped when I filled it up. I assumed (wrongly it would seem!) that maybe there was an air lock that was leaking somewhere. This time round my coolant is fine so it can't be that, must have been entirely coincidental! Thinking about it, at the time I also checked the various pipes and connectors on the plenum - though all were OK. Is this where the purge valve comes from?
Is the valve situated on the cannister or somewhere else? (Havent got the bible here at work)
When I narrowed down the girlfriends problem to her purge valve I just disconnected it until the MOT came round (it would fail the emmissions without it) and it ran fine for a few months until she got round to getting a new one. Surely before the advent of carbon cannisters and all that (i'm old enough to remember!) this would have been vented to atmosphere anyway? Or just recycled back into the inlet manifold?
Mark
Last time it happened I happened to notice that I was slightly down on coolant, as it stopped when I filled it up. I assumed (wrongly it would seem!) that maybe there was an air lock that was leaking somewhere. This time round my coolant is fine so it can't be that, must have been entirely coincidental! Thinking about it, at the time I also checked the various pipes and connectors on the plenum - though all were OK. Is this where the purge valve comes from?
Is the valve situated on the cannister or somewhere else? (Havent got the bible here at work)
When I narrowed down the girlfriends problem to her purge valve I just disconnected it until the MOT came round (it would fail the emmissions without it) and it ran fine for a few months until she got round to getting a new one. Surely before the advent of carbon cannisters and all that (i'm old enough to remember!) this would have been vented to atmosphere anyway? Or just recycled back into the inlet manifold?
Mark
Well how annoying is that! She did chuck out handfulls of sooty condensate on firing up but I guess that is to be expected. A test run to the petrol man and the post office man revealed nothing. Usual pressure equalisation from the tank when removing filler cap. Running sweet as a 450 ever did. No fault codes. Run included about five minutes at 3+k revs.
And like Sparky11 the whistle has gone! My rummaging around to find where the can and hoses are could have shifted something. Mabye even knocked the valve on top of the can? Difficult to see with your arm up to the elbow through the big hole in the front, around the washer bottle and into the unknown under the headlight!
Seems to me the whole thing may just come out through the access hole for the headlight bulb. Anybody know for sure?
And like Sparky11 the whistle has gone! My rummaging around to find where the can and hoses are could have shifted something. Mabye even knocked the valve on top of the can? Difficult to see with your arm up to the elbow through the big hole in the front, around the washer bottle and into the unknown under the headlight!
Seems to me the whole thing may just come out through the access hole for the headlight bulb. Anybody know for sure?
Thanks, that was what I was afraid of! Fortunately (or unfortunately depending on how you view these things) my symptoms have cured themselves so I am no wiser as to whether my code 88 was a power up check or a purge valve fault.
I think I would have been tempted to enlarge the hole and fabricate a new cover rather than mess with the rad. What prompted you to change the canister?
Cheers
Trevor
I think I would have been tempted to enlarge the hole and fabricate a new cover rather than mess with the rad. What prompted you to change the canister?
Cheers
Trevor
I changed it in an attempt to source the strong smell of petrol I get in the car when I have the driver's window open. I have found that it has improved it a bit but not completely. It was at its worst when the car was hot and stuck in traffic.
I tried to enlarge the hole but I realised that it was going to have to go quite a long way towards the centre of the car to miss the headlight adjustment screws.
I had the rad out in about 20 minutes - just lucky from what I've read on other threads.
I tried to enlarge the hole but I realised that it was going to have to go quite a long way towards the centre of the car to miss the headlight adjustment screws.
I had the rad out in about 20 minutes - just lucky from what I've read on other threads.
Edited by TVRPierre on Thursday 14th June 20:13
I've had some strange problems,sometimes the tank goes boing after a run,but only sometimes.Also occasionally there is a strong smell of petrol in the car,after filling up.The smell comes through the vents from the boot,can this be a problem with the purge valve?There are no visable leaks and it goes away after restarting the car.Also on the London Thunder run last year,the car smelt of petrol after idling for several hours,the smell went when the engine revs were up.
I must say that my boot regularly smells of petrol, not necessarily after filling up. I have checked and so has the indie that I bought car from but we can't find a leak. Could the fumes be coming in through boot vents or being drawn in through my window and then into the boot? I just don't know!
Not many folks check the unions on the tank or the vent & return pipes for cracks etc. But they do take a fair bit of abuse under the car & from exhaust heat over time.. Carbon cars are designed to be replaced something like every 5 years as well IIRC. If the purge valve/ecu is not sucking them out every now & again they can fill up pretty quick I believe.
Dave
Dave
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