Water in Fuel Tank - Petrol

[Stumac Lurker Find all posts View Profile Close Stumac]

Afternoon All,

First post on PP! Purchased a used 120 V6 from a dealer and went straight up to DI - all in perfect working order and lookover by my mechanic. Refilled at a shell servo (~110L of 91RON) on the way home and ran it over an underbody wash. A few kms down the road engine light came on = me sh*tting myself re new toy. Cleaned the car all over and woke up the next morning - no engine light. 2 days later - engine light back on. Took it back to dealer straight away and today they've come back to me with water in the fuel tank. "looks like dirty creek water" was the mechanics words! Forgotten the codes the ECU was throwing but was 02 sensor...How the hell water got in there I have no idea - my theories include contaminated tank at servo (called and no one else has had a problem) or second tank had not been used for a while prior to purchase and contaminants were sitting there...Engine was idling sssslighty rougher than normal (could be my imagination) but apart from that no loss of power etc.

Anyway ~$500 to flush tanks and lines + new filter. any other way of getting water out of tank? any ideas on how it got there? Will flush it regardless I'm thinking.

any feedback/similar experiences would be appreciated.

Cheers,

[Bushbasher Out of control poster! Find all posts View Profile Close Bushbasher]

The car doesn't run on one tank and then switch to another, that's not how the fuel system works. Fuel is continually transferring from one tank to the engine and then excess fuel returns to the other tank before moving into the main tank and repeating the process. In short, it would be rare to have contamination only in one tank. Quite often, Toyota's first response to any engine issue is "you must have picked up some dirty fuel." They tried that one on me when my engine blew up.

[topic97 Senior Member Find all posts View Profile Close topic97]

The car doesn't run on one tank and then switch to another, that's not how the fuel system works. Fuel is continually transferring from one tank to the engine and then excess fuel returns to the other tank before moving into the main tank and repeating the process. In short, it would be rare to have contamination only in one tank. Quite often, Toyota's first response to any engine issue is "you must have picked up some dirty fuel." They tried that one on me when my engine blew up.

Yeah but if the previous owner had only been putting say $50 a time in the car, then the rear tank would be sitting there dormant.
From what I understand, when you are filling up the front tank always fills up first & then overflows into the second tank when its full.

So by my thinking, it could be quite possible the other tank was contaminated if the old owner was a tightarse! lol

[topic97 Senior Member Find all posts View Profile Close topic97]

Dont worry, I just re-read your post about transferring.
Nevermind....lol

[topic97 Senior Member Find all posts View Profile Close topic97]

But even if it was "dirty fuel", doesn't the pump pick-up from the bottom or near the bottom of the tank?
Meaning that even if there was water in the fuel, it wouldn't have picked it up on full tanks?
And how would the dealer know there is water in the fuel without emptying the tanks - essentially cleaning the tanks anyway?!

[Stumac Lurker Find all posts View Profile Close Stumac]

Pretty sure most vehicles have a fuel test port...

[Pedro Advanced Member Find all posts View Profile Close Pedro]

This is why I fitted a water sedimenter http://www.pradopoint.com/showthread...l=1#post152076

[Bushbasher Out of control poster! Find all posts View Profile Close Bushbasher]

Pretty sure most vehicles have a fuel test port...

No, they undo the bung at the bottom of the tank and drain the fuel first. The tank is then removed and they open the fuel pump panel on the top of the tank.

[Stumac Lurker Find all posts View Profile Close Stumac]

No, they undo the bung at the bottom of the tank and drain the fuel first. The tank is then removed and they open the fuel pump panel on the top of the tank.

Bung only on secondary tank

[turtlewa Member Find all posts View Profile Close turtlewa]

Depending on how much water try a bottle of metho first

[Stumac Lurker Find all posts View Profile Close Stumac]

*Update*
Went and picked up fuel sample from dealer and took car to my mechanic - still runs fine no loss of power or rough idle so we're assuming no damage to injectors. Fuel sample was red/orange colour w/ strong odour with a lot of sediment settled at the bottom...I'm saying no water contamination just sediment.

Lesson learnt: buying secondhand car with a few kms on it and a long range tank...spend that little extra on flushing the tanks before filling up.