Water in fuel filters, potential noob question.

SeanW

Hi everyone,

In a bit of a bind with my ride and need some advice. Hope sum1 can help

Abridged version, my car is a 99 Avensis 2.0 diesel, which has been working fine for the most part but a few months ago, while far from home and out of hours, my car dashboard showed a water-in-the-fuel-filters warning. Didn't know what it meant at the time because I hadn't seen it before, so I pulled in first place I could and looked up the owners manual. It said that the water level in the fuel filters had reached "the specified level" and that I should not continue to drive the car before following a procedure for draining the filters. I did drive it onwards anyway but stopped part of the way home and tried to follow the manual.

Obviously I must have made some n00b mistake or the owners manual lead me up the garden path because I ended up airlocking the fuel system and the car had to be towed to my usual mechanic.

Mechanic said that the car was fine, that there's plenty more room in the fuel filters for more water when that light comes on, and that I should NOT try to strain the filters myself because I'd only end up airlocking it instead, so I should take it as a service reminder and bring it to a garage ASAP instead of stopping on the spot. Fuel filters were changed anyway as they were due.

Fast forward two or three months to a couple of weeks ago, the light comes on again and I take it to the garage. Filters strained, light off, off I go. Yesterday, driving home (only 150 miles or so since the last incident), it starts flickering on again, not constant, went off when I idled the car on a flat driveway. Makes me think its filling up again and the light flickers on when the water bounces around.

Obviously I can't bring it to the mechanic again for now because it's Christmas time. But I should probably try and strain out all that water, in any case whatever the heck is going on, I've obviously got a water problem in the fueling aparatus somewhere and am probably going to have to deal with this routinely, at minimum until my current tankful of fuel is used up, possibly longer if there's something else going on.

I'd be grateful if anyone here who knows anything about cars (unlike me ) can give me some useful advice.

gctest50

you might need to drain the fuel tank - probably loads of water sloshing around in there

CJhaughey

In the meantime, on the bottom of the fuel filter is a plastic wingnut that you open to drain the water, it only needs to drain a couple of eggcups to drain the water, after you drain it the little black mushroom on top of the filter housing should prime it again.
The prime pumps do fail after a while so be wary of it not priming properly.
Is your filler cap ok and not broken or missing?

Toyotafanboi

could it be possibly a faulty sensor and there is actually no water content.

i'd imagine the car would have running issues if it were genuinely able to fill the diesel filter with water to a "dangerous" level in 150 miles.

SeanW

Merry Xmas all and thanks for the replies.

gctest50 wrote: »

you might need to drain the fuel tank - probably loads of water sloshing around in there

Possibly. Though I'm not sure how; my most recent troubles started after a large fill (from 1/4 full to full) from a petrol station and brand I don't normally use. Not gonna name it though in case it's not at fault.

CJhaughey wrote: »

In the meantime, on the bottom of the fuel filter is a plastic wingnut that you open to drain the water, it only needs to drain a couple of eggcups to drain the water, after you drain it the little black mushroom on top of the filter housing should prime it again.
The prime pumps do fail after a while so be wary of it not priming properly.
Is your filler cap ok and not broken or missing?

The filler cap is OK I think, but I can check. The rest of the comment has me interested though. The first time this happened I tried to follow the draining procedure but airlocked the system.

The owners manual told me to turn that spigot on the bottom 2 1/2 times, press that big button on the top of it until fuel (instead of water) came out then turn the spigot back to a sealed position. Not being sure when that might have occurred, I kept pressing that button thing and pumping out liquid until no more liquid came out. Then I started the car, it ran for a very short time before "chucking" and finally packed in. That's when I had to get it towed.

That's why I was wondering if I'd made some n00b mistake or why the mechanic told me not to try to drain the water myself?

Toyotafanboi wrote: »

could it be possibly a faulty sensor and there is actually no water content.

i'd imagine the car would have running issues if it were genuinely able to fill the diesel filter with water to a "dangerous" level in 150 miles.

What sort of running issues?

CJhaughey

SeanW wrote: »

The owners manual told me to turn that spigot on the bottom 2 1/2 times, press that big button on the top of it until fuel (instead of water) came out then turn the spigot back to a sealed position. Not being sure when that might have occurred, I kept pressing that button thing and pumping out liquid until no more liquid came out. Then I started the car, it ran for a very short time before "chucking" and finally packed in. That's when I had to get it towed.

Best to put a jar or similar container under the outlet when you push the primer.
That way you can just pump a small amount out and see when it is fuel not water.
Easy to see when it settles after a minute.
4-5 slow pumps should empty the water out.
Close the wingnut and pump until you feel the resistance of the pump increase slightly.
You probably pumped the filter dry and thats why it airlocked.
I have the same car and engine and haven't had any issues with water in the fuel, maybe its just a small amount of water or a sticky float switch in the white piece on the bottom of the filter.
Change the filter at least once a year, better to do it every 6 mths.
You can do it yourself easily enough.
Try draining it again and not pumping too much next time.

Toyotafanboi

SeanW wrote: »

What sort of running issues?

well, just doing the man maths.

you say you had the filter drained and the light turned out, then 150 miles later it was back on again.

lets say the avensis does a conservative 45mpg, that means it took the car 15.1 litres to do those 150 miles.

lets say it's a 500ml filter and the "critical" level for water is 300ml (60% of it's content), that means that every litre of "content" in your fuel tank is 980ml diesel and 20ml water. that means, if you have a 60 litre tank that at any given time (seeing as this problem appears to be continuous) there is 1.2 litres of water in your fuel tank.

or to put it another way, every time you pump €50 into your car, you've bought 39.2 litres of diesel and 800ml of water.

where do you buy your fuel?

i'm just not gone on that as a theory, which is why my money, for now is on a faulty sensor, but i could be very wrong.

gctest50

Toyotafanboi wrote: »

.........

i'm just not gone on that as a theory, which is why my money, for now is on a faulty sensor, but i could be very wrong.

you need to capture what you drain out of the water trap so you can have a good look at it otherwise you'd be guessing for ever - cut down a 2 litre plastic bottle or something

George Dalton

As above, what I would do if I were you is remove the complete filter housing and drain the contents into a clear container. Then you know for sure whether you fuel problem or a sensor problem.

If you do have water in the fuel system then try finding a stockist of Wurth Fuel Cure. We have had good results using it on cars with water contamination in the fuel system.

http://www.ebay.co.uk/itm/Wurth-Fuelcure-cures-moisture-water-contamination-in-Diesel-Petrol-tanks-/221360568795?pt=LH_DefaultDomain_3&hash=item338a1e39db

SeanW

Toyotafanboi wrote: »

well, just doing the man maths.

you say you had the filter drained and the light turned out, then 150 miles later it was back on again

...

where do you buy your fuel?

i'm just not gone on that as a theory, which is why my money, for now is on a faulty sensor, but i could be very wrong.

Fair enough.

The first time it happened, there was nothing unusual, the filters had been in place for some time and TBH they were well due to be changed anyway.

Then it was fine for 2-3 months. That's when it happened again twice in short succession, the only thing different was that just before the last two occurances I went to a filling station that I don't normally use and filled the tank to the top, from where it had been about 1/3 full. I drove another 30-40 miles that night then the light came on during a short drive the following day.

I would suspect that the new fuel was bad (maybe the dregs of their tank?) but I'm not planning right now to name the place in case it wasn't the problem.

@George Dalton, would you have any idea where I could find that stuff in the Midlands?

George Dalton

What part of the Midlands?

SeanW

George Dalton wrote: »

What part of the Midlands?

Longford (but I could go ~30 miles or so in any direction). But if there's a place in Dublin that sells it that would work too.