Water in fuel tank...
Discussion
My 2002 Ford Focus (petrol) acts as a reservoir/store whenever I empty fuel tanks on other cars, lawnmowers etc...
At some point I think some water must have gone in. When I get down to 1/4 tank or less the ride gets very lumpy and is only cured by filling the tank up with fresh petrol. Is the only solution to get it down to 1/4 tank and drain the tank - or is there a smarter way.
What do I do with the petrol I've drained out - what would be a responsible way of getting rid of it?
At some point I think some water must have gone in. When I get down to 1/4 tank or less the ride gets very lumpy and is only cured by filling the tank up with fresh petrol. Is the only solution to get it down to 1/4 tank and drain the tank - or is there a smarter way.
What do I do with the petrol I've drained out - what would be a responsible way of getting rid of it?
GreenV8S said:
Petrol and water don't mix. The water floats on top of the petrol. If you let the fuel settle and then drain off the contents of the tank you will probably find that a quarter of the tank is smelly water rather than petrol.
Not true ! Water is more dense than fuel therefore the fuel floats on the top of the water.
This problem sounds like one I had in an Integrale several years ago, similar symptoms, the fuel pump was submerged in the tank ,there was a rubber fuel hose which connected the pick-up to the inlet of the pump, this had perished and when the fuel level fell below the level of the hole it ingested air, causing the vehicle to cut out.
If the OP has a submerged pump, that is where I would suggest he starts looking.
Auntieroll said:
This problem sounds like one I had in an Integrale several years ago, similar symptoms, the fuel pump was submerged in the tank ,there was a rubber fuel hose which connected the pick-up to the inlet of the pump, this had perished and when the fuel level fell below the level of the hole it ingested air, causing the vehicle to cut out.
If the OP has a submerged pump, that is where I would suggest he starts looking.
This.If the OP has a submerged pump, that is where I would suggest he starts looking.
227bhp said:
I think you've misdiagnosed your problem, but the best way to get rid of contaminated fuel is to burn it - very carefully if its petrol.
What is your theory? Genuinely keen to know (and why my theory is wrong). I'm currently dealing with a fuel leak on the 308 and I have had enough of petrol issues!Do you share the submerged pump idea?
Just had a flick through the Haynes manual and replacing the fuel pump looks tedious but not impossible.
ATS fitted a new exhaust system at the weekend (for some reason I never think of doing exhaust work myself) - so at least that won't be seized up as much of it needs to be moved or removed to gain access to the tank.
New pumps start around £60 but I guess I should get the old one out and see if I can replace a £2 hose first!
When ATS replaced the exhaust, the invoice recorded the EuroCarParts parts number, which meant that pricing the job was easy... £100 parts, £180 labour. Next time I'll do it myself!
ATS fitted a new exhaust system at the weekend (for some reason I never think of doing exhaust work myself) - so at least that won't be seized up as much of it needs to be moved or removed to gain access to the tank.
New pumps start around £60 but I guess I should get the old one out and see if I can replace a £2 hose first!
When ATS replaced the exhaust, the invoice recorded the EuroCarParts parts number, which meant that pricing the job was easy... £100 parts, £180 labour. Next time I'll do it myself!
paintman said:
Auntieroll said:
This problem sounds like one I had in an Integrale several years ago, similar symptoms, the fuel pump was submerged in the tank ,there was a rubber fuel hose which connected the pick-up to the inlet of the pump, this had perished and when the fuel level fell below the level of the hole it ingested air, causing the vehicle to cut out.
If the OP has a submerged pump, that is where I would suggest he starts looking.
This.If the OP has a submerged pump, that is where I would suggest he starts looking.
Not at all, it doesn't make sense.
Andy 308GTB said:
227bhp said:
I think you've misdiagnosed your problem, but the best way to get rid of contaminated fuel is to burn it - very carefully if its petrol.
What is your theory? Genuinely keen to know (and why my theory is wrong). I'm currently dealing with a fuel leak on the 308 and I have had enough of petrol issues!Do you share the submerged pump idea?
"the ride gets very lumpy"
Sounds like you're driving down a cobbled road, can you expand on this?
Like the chap says up there ^^ water sinks to the bottom so there goes your theory i'm afraid.
If you genuinely do have an issue at below 1/4 tank then yes I'd expect the answer to be in the tank so take a look in there. It looks like a dropping tank job which won't be enjoyable, I have seen it done pie key style where they cut a hole in the metalwork under the rear seat to get access, but it's not a great idea.
I wonder if the pump isn't sitting on the bottom of the tank? The pump and float assembly (which sends the signal to the gauge) are together in the same unit, are you sure you do have about 1/4 tank left? Does it figure with the mileage covered?
Andy 308GTB said:
227bhp said:
I think you've misdiagnosed your problem, but the best way to get rid of contaminated fuel is to burn it - very carefully if its petrol.
What is your theory? Genuinely keen to know (and why my theory is wrong). I'm currently dealing with a fuel leak on the 308 and I have had enough of petrol issues! Do you share the submerged pump idea?227bhp said:
I was pointing out you were wrong, not that I had an answer
This is the internet. Forum Law says you must have an answer or an opinion. It also states that you cannot change your stance regardless of the information you receive subsequently. You must stand and defend your original statement. See the NP&E section for examples.227bhp said:
"the ride gets very lumpy". Sounds like you're driving down a cobbled road, can you expand on this?
The car/engine judders, it isn't misfiring. I guess this adds weight to your suggestion regarding fuel starvation/running out of petrol.I have thought this through now and my plan is...
1. Brim the petrol tank.
2. Record the mileage
3. Drive until the car judders (but carry a can of petrol in the boot in case it happens somewhere inconvenient)
4. Record what the petrol gauge reads
5. Brim the petrol tank and record how much petrol it takes - compare this to the tank capacity
6. Do the mileage sums as a back up
Thinking back, my wife did have an issue with the car running out of petrol when the tank showed 1/2 full about 10/12 years ago. I'll have to dig through the service history to see the outcome of that. But it sounds suspiciously similar...
Thanks all for your input. I'll report back if the outcome is vaguely interesting...
Pffft forum law. This PH place is like America, we have different laws in different states, so it does not apply in the Technical section.
I'd start with the easy stuff first and a bit of careful monitoring.
Although after giving it some more thought in the bath...Does this car have a turbo? If so it may be worth seeing what happens when it's under full load and fuel demand is at its greatest. If you detect a slight power loss or misfire then it could be a slight leak on the assembly somewhere.
Why I thought the comparison with the old Lancia was invalid was because I believe they were largely made in the 80s and 90s. This was 'pre unleaded fuel' time, when the change happened to the more aggressive fuel it will have rotted the hoses as it did to quite a few cars.
Yours being well after that means they should be prepared. I think those turbo cars with in tank pumps suffered under heavy load as the porous rubber pipe caused a loss of pressure no matter if the tank was empty or full whereas yours has more modern plastic ones.
But things aren't always black and white so let's take that idea and expand on it, it's down to the degree off loss. The actual figures are rough, but here is the theory:
Initially if a pressurised hose is leaking in the tank it will do this no matter how much fuel is in there, but whilst it can lose pressure and fuel it can't take in air if it is submerged. Lets say a pump supplies 12 bar, but rail pressure is 3. This means we can actually lose 9bar through a leak and the car will still function.
It's possible there is a slight leak on your assembly somewhere so rail pressure is down, but not critical. When the fuel level gets low then air can actually get in so the pressure may go even lower, but more importantly will now have air bubbles in it too.
So I would guess Auntieroll wasn't far off the mark, close but no cigar.
I'd start with the easy stuff first and a bit of careful monitoring.
Although after giving it some more thought in the bath...Does this car have a turbo? If so it may be worth seeing what happens when it's under full load and fuel demand is at its greatest. If you detect a slight power loss or misfire then it could be a slight leak on the assembly somewhere.
Why I thought the comparison with the old Lancia was invalid was because I believe they were largely made in the 80s and 90s. This was 'pre unleaded fuel' time, when the change happened to the more aggressive fuel it will have rotted the hoses as it did to quite a few cars.
Yours being well after that means they should be prepared. I think those turbo cars with in tank pumps suffered under heavy load as the porous rubber pipe caused a loss of pressure no matter if the tank was empty or full whereas yours has more modern plastic ones.
But things aren't always black and white so let's take that idea and expand on it, it's down to the degree off loss. The actual figures are rough, but here is the theory:
Initially if a pressurised hose is leaking in the tank it will do this no matter how much fuel is in there, but whilst it can lose pressure and fuel it can't take in air if it is submerged. Lets say a pump supplies 12 bar, but rail pressure is 3. This means we can actually lose 9bar through a leak and the car will still function.
It's possible there is a slight leak on your assembly somewhere so rail pressure is down, but not critical. When the fuel level gets low then air can actually get in so the pressure may go even lower, but more importantly will now have air bubbles in it too.
So I would guess Auntieroll wasn't far off the mark, close but no cigar.
Edited by 227bhp on Monday 5th March 12:20
How well damped is the fuel gauge? The gauge on my V8S is pretty inaccurate at the bottom of the gauge, but it responds quickly enough that I can see the gauge move during cornering as the fuel sloshes around. If you throw the car around a bit while the problem happens and see the gauge move, that suggests there's still petrol in the tank and would support the theory there's a leaky pipe inside the tank. If you know the nominal tank capacity, just measuring how much it takes to brim it should tell you that as well.
Turbo
It's a 2002 Focus Estate (1.8) with 110,000 miles on the clock, so the only performance you'll see is down to a heavy right foot.
The fuel gauge is steady as a rock, rises and falls smoothly.
The thought of spending money or my Saturday underneath the car is sufficient incentive to conduct the 'brim' tests for the next week or two.
Edited to add, it is a submerged pump.
It's a 2002 Focus Estate (1.8) with 110,000 miles on the clock, so the only performance you'll see is down to a heavy right foot.
The fuel gauge is steady as a rock, rises and falls smoothly.
The thought of spending money or my Saturday underneath the car is sufficient incentive to conduct the 'brim' tests for the next week or two.
Edited to add, it is a submerged pump.
Edited by Andy 308GTB on Monday 5th March 12:34
227bhp said:
Pffft forum law. This PH place is like America, we have different laws in different states, so it does not apply in the Technical section.
I'd start with the easy stuff first and a bit of careful monitoring.
Although after giving it some more thought in the bath...Does this car have a turbo? If so it may be worth seeing what happens when it's under full load and fuel demand is at its greatest. If you detect a slight power loss or misfire then it could be a slight leak on the assembly somewhere.
Why I thought the comparison with the old Lancia was invalid was because I believe they were largely made in the 80s and 90s. This was 'pre unleaded fuel' time, when the change happened to the more aggressive fuel it will have rotted the hoses as it did to quite a few cars.
Yours being well after that means they should be prepared. I think those turbo cars with in tank pumps suffered under heavy load as the porous rubber pipe caused a loss of pressure no matter if the tank was empty or full whereas yours has more modern plastic ones.
But things aren't always black and white so let's take that idea and expand on it, it's down to the degree off loss. The actual figures are rough, but here is the theory:
Initially if a pressurised hose is leaking in the tank it will do this no matter how much fuel is in there, but whilst it can lose pressure and fuel it can't take in air if it is submerged. Lets say a pump supplies 12 bar, but rail pressure is 3. This means we can actually lose 9bar through a leak and the car will still function.
It's possible there is a slight leak on your assembly somewhere so rail pressure is down, but not critical. When the fuel level gets low then air can actually get in so the pressure may go even lower, but more importantly will now have air bubbles in it too.
So I would guess Auntieroll wasn't far off the mark, close but no cigar.
Read my post again , I specified the SUCTION pipe, the one that leads from the pick up to the I'd start with the easy stuff first and a bit of careful monitoring.
Although after giving it some more thought in the bath...Does this car have a turbo? If so it may be worth seeing what happens when it's under full load and fuel demand is at its greatest. If you detect a slight power loss or misfire then it could be a slight leak on the assembly somewhere.
Why I thought the comparison with the old Lancia was invalid was because I believe they were largely made in the 80s and 90s. This was 'pre unleaded fuel' time, when the change happened to the more aggressive fuel it will have rotted the hoses as it did to quite a few cars.
Yours being well after that means they should be prepared. I think those turbo cars with in tank pumps suffered under heavy load as the porous rubber pipe caused a loss of pressure no matter if the tank was empty or full whereas yours has more modern plastic ones.
But things aren't always black and white so let's take that idea and expand on it, it's down to the degree off loss. The actual figures are rough, but here is the theory:
Initially if a pressurised hose is leaking in the tank it will do this no matter how much fuel is in there, but whilst it can lose pressure and fuel it can't take in air if it is submerged. Lets say a pump supplies 12 bar, but rail pressure is 3. This means we can actually lose 9bar through a leak and the car will still function.
It's possible there is a slight leak on your assembly somewhere so rail pressure is down, but not critical. When the fuel level gets low then air can actually get in so the pressure may go even lower, but more importantly will now have air bubbles in it too.
So I would guess Auntieroll wasn't far off the mark, close but no cigar.
Edited by 227bhp on Monday 5th March 12:20
Inlet port of the pump.
Auntieroll said:
Read my post again , I specified the SUCTION pipe, the one that leads from the pick up to the
Inlet port of the pump.
I've just concluded your idea is quite possibly not far off the mark, but there is no suction pipe, if there was there wouldn't be an issue with it no matter how many holes it had in itInlet port of the pump.
The pump sucks through its base and pushes out through a port in the top where the pressurised pipe is fixed.
227bhp said:
Auntieroll said:
Read my post again , I specified the SUCTION pipe, the one that leads from the pick up to the
Inlet port of the pump.
I've just concluded your idea is quite possibly not far off the mark, but there is no suction pipe, if there was there wouldn't be an issue with it no matter how many holes it had in itInlet port of the pump.
The pump sucks through its base and pushes out through a port in the top where the pressurised pipe is fixed.
Personal experience with boat fuel tanks on that one as the pump is at the engine & seen it on both outboard & inboard equipped boats.
Can also be an issue with a saddle type fuel tank if the pump that moves fuel from one side of the saddle to the main pump side fails as the fuel won't just syphon from one side to the other. An issue that affects the L322 & the symptom is engine stalling & fuel warning display even though the fuel gauge shows 1/4 ish of a tank of fuel remaining - has come up twice recently on LR forums & was TDV6 on both occasions.
I will provide this update but it's very dull and probably inconclusive.
FYI The tank capacity is 55 litres.
A week or so ago, I had the car almost out of fuel but running fine. Parked up. Tried to start it but it wouldn't start. It took 51 litres of fuel and was then fine.
Yesterday, the petrol warning light came on and the car starting juddering within a few seconds. I was 1/2 mile away from a petrol station so I pushed on. The car would idle just fine but had no power. I had to get the revs up to keep going and I could drive 50 yards or so before it felt like it was going to die. I would stop, the idle would be fine but again very little power. The convoy of cars behind me was surprisingly patient. I was able to put 50 litres of fuel into the car.
I'm going to change the fuel filter this weekend (I tried last weekend but they are a b
d to get to. Probably why the original part hasn't been changed in 16 years) for what it's worth. I still think that there is something wrong here but the options will get really nasty.
I'm not taking this too seriously, the car has an insurance value of £148 but I pride myself in being able to fix things.
FYI The tank capacity is 55 litres.
A week or so ago, I had the car almost out of fuel but running fine. Parked up. Tried to start it but it wouldn't start. It took 51 litres of fuel and was then fine.
Yesterday, the petrol warning light came on and the car starting juddering within a few seconds. I was 1/2 mile away from a petrol station so I pushed on. The car would idle just fine but had no power. I had to get the revs up to keep going and I could drive 50 yards or so before it felt like it was going to die. I would stop, the idle would be fine but again very little power. The convoy of cars behind me was surprisingly patient. I was able to put 50 litres of fuel into the car.
I'm going to change the fuel filter this weekend (I tried last weekend but they are a b
d to get to. Probably why the original part hasn't been changed in 16 years) for what it's worth. I still think that there is something wrong here but the options will get really nasty.I'm not taking this too seriously, the car has an insurance value of £148 but I pride myself in being able to fix things.
It won't be water in the tank.
The specific gravity of tap water is around 1.05.
The specific gravity of pump petrol is around 0.75.
The petrol floats on the water and your fuel tank take off point is obviously at the bottom of the tank, so if it was water in the tank it would be trying to run on it all of the time & would not start.
It is far more likely that there is an issue with your in-tank fuel pump/filter assembly causing it to pick up air below a certain level of fuel in the tank.
It looks like this & a simple crack or something an inch or so up the case will cause it to pull in air & do exactly what you say.
https://www.ebay.co.uk/itm/Ford-Focus-MK2-ST-2-5-P...
The specific gravity of tap water is around 1.05.
The specific gravity of pump petrol is around 0.75.
The petrol floats on the water and your fuel tank take off point is obviously at the bottom of the tank, so if it was water in the tank it would be trying to run on it all of the time & would not start.
It is far more likely that there is an issue with your in-tank fuel pump/filter assembly causing it to pick up air below a certain level of fuel in the tank.
It looks like this & a simple crack or something an inch or so up the case will cause it to pull in air & do exactly what you say.
https://www.ebay.co.uk/itm/Ford-Focus-MK2-ST-2-5-P...
E-bmw said:
It won't be water in the tank.
The specific gravity of tap water is around 1.05.
The specific gravity of pump petrol is around 0.75.
The petrol floats on the water and your fuel tank take off point is obviously at the bottom of the tank, so if it was water in the tank it would be trying to run on it all of the time & would not start.
It is far more likely that there is an issue with your in-tank fuel pump/filter assembly causing it to pick up air below a certain level of fuel in the tank.
It looks like this & a simple crack or something an inch or so up the case will cause it to pull in air & do exactly what you say.
https://www.ebay.co.uk/itm/Ford-Focus-MK2-ST-2-5-P...
Not what I wanted to hear but I'm sure you are correct.The specific gravity of tap water is around 1.05.
The specific gravity of pump petrol is around 0.75.
The petrol floats on the water and your fuel tank take off point is obviously at the bottom of the tank, so if it was water in the tank it would be trying to run on it all of the time & would not start.
It is far more likely that there is an issue with your in-tank fuel pump/filter assembly causing it to pick up air below a certain level of fuel in the tank.
It looks like this & a simple crack or something an inch or so up the case will cause it to pull in air & do exactly what you say.
https://www.ebay.co.uk/itm/Ford-Focus-MK2-ST-2-5-P...
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