[Sudipto-S-Team]

I recently faced this problem of water contamination in my petrol tank during my recent trip to Bhutan. I am told, this is a rather common problem you have to deal with while traveling on Indian highways. I will detail my experience and would love to know the experts' views on this.
I had to tank up several times during my journey and somehow water got into my tank, which subsequently resulted in the engine behaving in a strange way. I wasn't getting enough power and the engine was kind of stuttering.
After coming back from the trip the MASS mechanic suspected and discovered water in the tank. They threw away the contaminated petrol, cleaned the tank thoroughly, cleaned the fuel line by running air through it. The car now behaves like new. In fact it feels much peppier than what it was before I started this long journey.
Now the question is how do you deal with this problem in future on the highway? I am told mixing methylated spirit in the tank helps as it mixes with the water and then burns it up. Could chemical engineers and people in the know help me by giving a plausible answer? Because this is one problem that has to be cured and cannot be endured.
How much methylated spirit should be mixed? I am sure that would depend on the amount of water inside the tank. But some general rule of thumb will help.
I hope this thread has been posted in the correct section. It's indeed a technical question, though not directly related to the mechanics of the car itself. Also I could not find this subject discussed anywhere else.

[tsk1979]

Thankfully tata gives a sedimeter which takes care of this probem.
As for Ethanol/Methanol in fuel tank, I think already there is 5%(or is it more) mixing done in major towns. The plan is to get it to 10%

That said, water will settle down at the bottom of the tank, so if you can somehow drain 1-2 liters from the bottom, it will take care of this issue.

[greenhorn]

tsk, thats only there your white elephant(!) right ?
the indica doesnt have (at least the non dicor ones) a sedimenter right ?

[Sudipto-S-Team]

What's a sedimenter/sedimeter? How does it work?

Also, removing only the water from the bottom of the tank is not a viable and practical option on the highway. In fact even inside the garage it cannot be done, because the tank cannot be opened from the bottom.

I think I am going to put a couple of bottles of ethanol on my next road trip.

[Shashank.A]

I don't have much experience with it, but it happens in my bike. In rainy season if not covered properly, some water enters the fuel tank of my bike. However It is always trouble when the fuel level is low, last 20% in the tank. More than that it works normally.

Maybe something to do with the density of two liquids.

[tsk1979]

Yup, its only there in the safari.
The best way to avoid that is not to fill fuel just after a tanker has filled in the tanks at the pump. So if you see a parked tanker at the petrol pump, move on. Whenever the underground tanks of a petrol pump are filled, the debris and water gets swirled. After some time water and debris settles down.

[alpha1]

Ethanol/methanol will help in cleaning up the water form the bottom of the tank, certainly, because alcohol and water both are polar and miscible (unlike gasoline and water).
But I don't know how it (this mixture) would combust inside the cylinder.

[Rehaan]

Speaking of water and debris "settling down" to the bottom of the tank - (whether it be a tank at the petrol pump, or in your car) -- wouldn't it be logical to assume that the mouth of the pump / exit from the fuel tanks would also be at the lowest point possible ? ...which makes me question the above.

cya
R

[tsk1979]

Even I questioned this at Recong Peo.
When the safari broke down I asked the Petrol pump guy about water in fuel. He told me that the intake pump from the tank is at a slight height, because at the bottom there is usually too much debris.

[srijit]

Originally Posted by Rehaan

Speaking of water and debris "settling down" to the bottom of the tank - (whether it be a tank at the petrol pump, or in your car) -- wouldn't it be logical to assume that the mouth of the pump / exit from the fuel tanks would also be at the lowest point possible ? ...which makes me question the above.

I would think that it would be a bit above the lowest point in the tank. This would allow the dirty fuel to settle down in that part of the tank.

[hvkumar]

2 solutions:

- Refill in quarter-tank situation, so that at least even if there is water in the tank, it does not get injected into the engine, and remains at the bottom of the tank

- Select petrol pumps where fuel quality smells Ok - that is what I do, I stand by the side and stop refuelling if I suspect poor fuel quality, mostly adulteration, although water mixtures doe snot either show up or smell

[hydrashok]

Maybe we can test the petrol by pumping a bit into a 3L bottle first? This is what I do when I have absolutely no option but tank up from a highway pump (esp. in the rain).

I got stuck (thankfully at the last leg) while returning home from a place 220kms away. My tank was nearly empty and I was 3 kms away from home. I thought I'd tank up before I get home and filled up the tank. I drove about 5 meters and the car shut down.

It was raining cats and dogs and with the help of the pump owner, I pushed the car into a (barely) roofed garage in the pump. The mechanic who arrived from the A.S.S. check the fuel line and IDd the problem. Reason: Water in Petrol, or more accurately, Petrol in Water. The car was towed to the A.S.S. (also, luckily just 4-5 kms away) by about 11.00PM. After the tank was drained the next day, we found that nearly all of what was filled was water.

I knew the pump owner well (right since my school days-- Dad used to fill up at his place), so I settled for a tankful of petrol and all expenses without causing any further problem. Since then I try not to fill petrol at unknown pumps, and when I do have to, I use the 3L Pepsi bottle to test. Not very accurate or certain, but it is better than nothing.

[sgiitk]

Water and Petrol are not miscible. So the water comes from the bottom of the storage tank when the tank is running low. As I understand the outlet pipe is floating on the liquid inside so if there is plenty of petrol then it will not pick up the water.

I had a situation where the tank of my 118NE was filled with pure water. The car stopped, and I had a bad time. Ended up emptying the tank and lines, and refilling with petrol at another pump. Happily, we were inside town so were not in as bad a mess as otherwise. Inquiry revealed that it had been drizzling, and water had entered the storage tank which was low on fuel.

Remember diesel and water are miscible. Water in diesel is a real problem, and many cars have elaborate arrangements to remove the water.

[Sudipto-S-Team]

Here is an interesting link on the subject. They are suggesting ethanol, methanol etc. Methyl alcohol is perhaps the cheapest option.

CR4 - Thread: Water Contaminated Petrol

I am most definitely going to carry a few litres during my next outing. But I must say - cleaning the fuel line improves performance like anything.

[GSMINC]

Originally Posted by hvkumar

Select petrol pumps where fuel quality smells Ok - that is what I do, I stand by the side and stop refuelling if I suspect poor fuel quality, mostly adulteration, although water mixtures doe snot either show up or smell

Detecting fuel adulteration just by smell, Now that's a tough one. Just dont think my sensory organs are that developed