[vigsom]

Originally Posted by Brumby

I accidentally added VW "Windscreen Clear Concentrate (will write it as WCC henceforth)" in fuel tank of my Polo GT TSI.

The ratio of mixture in the fuel tank is about 100ml of WCC in 30 ltrs of petrol 0.1:30 or 0.0033% by volume

please advise if there is a drain plug provided for the fuel tank of a Polo or for any of the cars.

Originally Posted by ajmat

I would fill the tank up completely, keep driving till 3/4 full, fill up, carry on and repeat cycle

Originally Posted by condor

100 ml over 30 litres is like 0.3% contamination, if I can call it that. Fuel from a bad bunk would have much more pollution from the pump itself. Even in the 0.3%, most of it is Ethanol.

If I were you, I'd just keep using the car since the contaminant here is just 100ml in a full tank. I agree with @ajmat's and @condor's points.

There is every possibility of more than 100ml water getting into the tank during the several normal fills from a fuel station during wet weather. So I wouldn't be too worried about what has happened in your case.

As far as I've seen, the last time I saw a drain plug on a fuel tank was on the Premier Padmini. Modern cars need to have
a) the rear seat bottom removed, the submersible pump assembly removed, and the fuel siphoned out
OR
b) the tank lowered, pump assembly removed, fuel siphoned out, tank cleaned out and re-installed.

Take a call.

[Indian2003]

You can also try to see if the windscreen washer liquid will dissolve in alcohol. If it does , put in 1/2 liter of technical alcohol. This will mix with the alcohol and diesel. For safe measure you can put in a 1/2 liter of 2-stroke oil.
I use alcohol in my diesel tank all winter to prevent condensation in the fuel system.

[hserus]

The first option by vigsom applies.

https://m.youtube.com/watch?v=iNonxdDhlx0

[2000rpm]

Simple solution actually, empty the current tank of petrol and use it for a low cost vehicle (carb bike??).

Dont risk running the car since its a POLO TSI, which is a mechanically complex car.

The risk is just not worth it.

[Brumby]

Originally Posted by Indian2003

You can also try to see if the windscreen washer liquid will dissolve in alcohol.

Probably you have misunderstood the engine to be a diesel engine, its a TSI petrol engine, so adding 2-stroke oil will probably ruin the fuel system.

Originally Posted by 2000rpm

Simple solution actually, empty the current tank of petrol and use it for a low cost vehicle (carb bike??).

I have finally planned to drain and flush the tank and fuel system at the ASS.

Meanwhile on 02 June 2021, I performed another test on the WCC. Took a small amount of WCC in a small bowl and used a match to light it, it's not highly volatile, but combusts easily with blue flame leaving a small amount of liquid which probably is the ethylene glycol (Glycerine) and detergent as residue. Its the residue part which got me to take the decision for going ahead with the option of cleaning the tank and the fuel system.

Spoke to the VW service center on 02 June 2021 for time and cost of fuel tank flush. It will take about 5-6 hours and will cost about INR 1200/- plus taxes and cost of fuel to complete the job.

Statement from the VW service advisor, "For a normal polo petrol, it will not make much of a difference, but for the TSI engine we must carry out the flushing of the tank". Probably a standard reply.

My logic and whatever limited knowledge that I have tells me there is no reason to worry, however I do not want to take a chance but what I am worried about is whether the technicians will be able to do a good job.

An unknown garage owner quoted INR 800/- procedure and equipment to be used is unknown.

The job was completed today at VW service center at Thane. The service center did not allow to take pictures of the procedure, however I will post the procedure separately in detail.

[himanshu_trikha]

Dear Brumby

Your faithfully is a Chemical Engineer working as Process Engineer for Refinery/Petrochemical Industry around 1.5 Decades so far.

Most WCC are a Mix of Alcohol, Antifreeze (EG) , Detergents, Lubricating agent and Phase stabilizer for keeping it in a single solution phase. Whenever you add a second HC phase to it ,Like Dissolves like applies and a few Polar (more dissolvable in water ) compound will form a second distinctive phase or layer.

This antifreeze and other things will settle down at tank as a very thin layer (20~30 ml in a 45 liter Tank ) but as per their chemical nature (and unknown nature of impurities) this can be corrosive to metal parts read Fuel Tank and ancillaries.

Scenario-1

Idle Layer

IMHO refilling multiple times will not help as this layer will be too low or below datum of Fuel Pump suction line to get into combustion chamber. This layer It will just remain there until the slow decomposition process starts. The volume and thickness of this layer is too low in my opinion to cause any significant damage.

Scenario-2

Combustion

Ethanol by now would have mixed with Gasoline and a this low concentrations its not a problem of any sort for any Gasoline ICE to handle. If this distinct layer (around 20-30 ml) gets into combustion chamber EG will burn at temperatures in north of 240 Deg C odd, remaining things shall be too low in quantity to cause any significant damage.

My Two Cents
Just do nothing ,its fine.
However, as I could gather about most T-BHPians and love for their machines, you will end up emptying the tank for peace of mind.

[Brumby]

Originally Posted by himanshu_trikha

Dear Brumby

Your faithfully is a Chemical Engineer working as Process Engineer for Refinery/Petrochemical Industry around 1.5 Decades so far.

Dear Himanshu, Thank you for the valuable input. I was looking forward to a response from a chemical engineer and as you have mentioned, the quantity that I accidentally added is not harmful for the engine.

In my earlier post, where I mentioned about mixing a small amount of WCC in petrol, the quantities mixed were in random proportions and the bubble that is visible is the detergent component of it. Your explanation makes it very clear.

I did go against the majority of the advise and against my logic and carried out the cleaning of the tank though, just to ensure no issues for my wife to handle in case there be.

During the cleaning no residue of WCC was found in the tank and probably it was already used in the engine by the time I reached home.

Thank you once again.

[himanshu_trikha]

Hey Brumby

I hope everything is working fine for you and wish that it continues.
Glad I Could help a bit.

Regards
Himanshu

[devilicious]

Good decision. This experiment was not worth the safety of your family and car. Hope everything's working fine now.

[Brumby]

Thank you everyone for advice and assistance.

I was away from civilisation for quite some time with very limited and expensive internet.

The car is running fine and there hasn't been any issue so far.

Thank you very much once again.