How dry do I need it?

[profjekyll]

Hi

I run a saxo 1.5 diesel with Bosch fuel pump. Have used 100% new SVO (from Makro) all summer (with a little blending in the Winter).

I hope to use cleaned up WVO. I have an upflow system that has been sitting for about 8 months (ranging from 0 degrees to 30 degrees in the summer).

The oil that comes out is rich red in colour. I filter this down to 1 micron.

When I hot pan test it, there is no spitting, but there are a few small bubbles.

I don't have the facility to use mains to heat the oil to get rid of the last little specks of water.

QUESTION: Is running this oil which has only this tiny bit of water (confirmed through hot pan testing) ok - or is it likely to cause serious damage to my car over time?

Many thanks in advance for your experience / opinions.

[Tony]

Welcome to the forum/wiki.

I don't think a very tiny amount of water like you describe will cause a problem at all.  Have you considered mixing a small quantity of petrol in with the waste oil to encourage water to separate more quickly?

[nigelb]

When I hot pan test it, there is no spitting, but there are a few small bubbles.

I don't have the facility to use mains to heat the oil to get rid of the last little specks of water.
cQUESTION: Is running this oil which has only this tiny bit of water (confirmed through hot pan testing) ok - or is it likely to cause serious damage to my car over time?

Many thanks in advance for your experience / opinions.

IMHO...and this is all it is......is even a small amount of water/moisture has the potential to cause you future issues. Water/moisture mixed with FFA's (free fatty acids) can cause short and long term isssues with injection pumps (IP's). FFA's are acids and can cause errosion in the precession machined injection pump.

As I say...just an oppinion.

[Jamesrl]

I'd have thought the same rules apply as wvo for bio,

Dry your oil

Dry your oil

And

Make sure your oil is DRY.

[Tony]

I can understand in principle why having oil or bio perfectly dry is seen as a good thing, but really - is a little going to cause any problems?

I know quite a few WVO users that make no attempt to dewater their oil.  Just a simple filtration system and off they go.

[greasemonkey]

Drying the oil is always going to be a good thing. A little bit of water isn't going to do any harm short term. The theory goes that suspended water in the oil will boil and explode under the big pressures in the injection pump, and take a tiny chunk of the pump with it. Over time, this can obviously lead to problems.
If there is free water in the oil, definitely don't put that in.

What I see about it is, that there must be condensation build up in the tank, so some water will be getting through anyway, best not add to it.

This is why industrial machines like diggers dumpers and tractors often have some kind of free water separator in the filter system. They are using way more fuel than a vehicle, so the risks are greater. They often form more condensation in the tank as well, because the tanks get hot in use. This is why they recommend filling the machine at the end of the day, to reduce the potential for condensation.

On the whole, I'd say best dewater if you can. I use the settling with petrol system on oil. Works for me.

[Keef]

I understand that but what about the condensation that must occur in your car fuel tank with changes in temperatures and humidity?

I've never heard of that being blamed for fuel system damage.

[greasemonkey]

I understand that but what about the condensation that must occur in your car fuel tank with changes in temperatures and humidity?

I've never heard of that being blamed for fuel system damage.

I wonder about that aswell. In my mind, the difference is that the condensation is a drop of water, that just drops to the bottom of the tank. You would think that over time this would accumulate, and fill the bottom of the tank with water, but obviously that doesn't happen. I know some diesels have a sensor in the bottom of the filter, that comes on if water is detected, but never really heard of them showing anything, so anyones guess how effective they are.

The difference with oil, in my mind, is that it is suspended water. I've had a cupful of water out of 40 litres of good looking filtered oil before now, by adding 10% petrol and leaving settle for 48 hours. So there would be a tiny bit of that going through the IP all the time.
It would be interesting to try the same with pump diesel and see what comes out. i bet there is some crap in that too.

Certainly on a machine, it's not uncommon to empty the water trap of water, but that is a different story. The tank gets a lot hotter, and is a lot bigger.

I don't know what the answer is really.

[Rotary-Motion]

I understand that but what about the condensation that must occur in your car fuel tank with changes in temperatures and humidity?

I've never heard of that being blamed for fuel system damage.

hmm good piont, specially winter and useing heat exchangers with returning oil being pretty hot

[julianf]

Remember where the condensation comes from - air.

For each fill of the tank, or part fill, etc, the same amount of air is passed into the tank - nothing more.

Ie if you brim the tank, use 20 ltrs, then 20 ltrs of air gets in.  Brim it again, and the 20 ltrs is displaced.  Use 20 ltrs, and that's 20 ltrs more air (etc. - im sure you get the idea : )


At 100% relative humidity, one cubic meter of air holds 9cc @ 10c or 17cc @ 20c

And thats at 100% - absolute saturation.  The forecast for this week here is about 80%.


The average day temp in the uk is probably not far off 10c.  So, if every day was 100% on the relative humidity scale, and you used every drop of your 2500ltr limit, that would give a potential 22.5 cc of water. 

And that's assuming that every bit of air that entered the tank was 100% saturated with water, and every bit that left was absolutely bone dry.

Even so, that would be 22.5cc of water, in 2500ltrs of fuel.  Certainly, if you dosed it all at once, im sure there would be issues, but at the percentages we're talking about (22.5cc as a percentage of 2500litres - absolute [ie unrealistic] worst case scenario at 10c) is it worth considering?



I dont know - in the past ive heard people blame a lot on "condensation" but ive never managed to make the numbers add up : )

[profjekyll]

Thanks for your replies guys... Esp Greasemonkey who has replied to this same question on another forum.  I am putting your idea into motion by the way, by taking 3 litres of oil, putting it into a clear container with 300ml of petrol in and observing the drop out.

To add some information, I have run the oil through a "Goden Rod" type filter too, which HAS NOT to any degree reduced the bubbling I find when doing the hot pan test.

For this reason, I believe the Golden Rod probably only takes out "free" water, and not suspended / colloid water.  For this same reason, I expect the oil only has suspended / colloid water and not "free" water in it.

With regards to water in the fuel pump "boiling" or evapourating / exploding, I think that could only happen if the oil / water was in a vacuum (and a pretty strong one at that).  I don't know the inner workings of the fuel pump, but I would have thought it would all be high pressure and not vacuum.

The Acidity of the system, however, would be a bit of a worry - wonder how much this would actually effect the system.

I guess my question really is "Has Anyone Ever Run A Car Like This (without it dying after a year or two) On WVO That Has MOST of The Water Taken Out, But Fails The Strictest Hot Pan Test?"

Thank you all again for the time you took to read etc... 

[greasemonkey]

I guess my question really is "Has Anyone Ever Run A Car Like This (without it dying after a year or two) On WVO That Has MOST of The Water Taken Out, But Fails The Strictest Hot Pan Test?"

)

I guess, the truth be known, that most people have chucked some rough old stuff in the tank at some time or another. I certainly have, right up to the point where it had no chance of getting from the tank to the lift pump............
Do you know anybody who has run an old car on pure pump diesel for a few years without a problem?
Just get another pump on standby, ready to fit. You'll probably have far more problems in running veg, before the pump packs in.

[Rotary-Motion]

some of the peugeot fuel filters have water drain off plugs at the bottom of the filter housing and also some cars have lights on the dash to warn of this some dont.

my 205 had a light on, i asked a mechanic as i couldnt work out what it was, he said drain the water out the filter, i did and it went out

[Tony]

They're for free water though rather than entrained water.  I agree with the sentiments above though, most of the time it will be at medium or very high pressure and so no opportunity to boil out.  Acids may affect the pump with very long term use, but I'd be surprised if even so the pump didn't outlast the vehicle.

[Rotary-Motion]

yes to free water, condensation from tanks i guess metal fuel tanks are worse than plastic for this