Water in a petrol car

motorguy

I got a local mechanic down to have a look. The plugs had rusted up so he cleaned them and tried to restart. Same problem.

We towed it up to his garage where basically he took the tank out and emptied it, added £15 of petrol and eventually it fired up!

All running good now. He charged me £60 all in including the £15 of petrol and tightening the exhaust (which was rattling a bit) - which i think was pretty cheap.

Thanks for all who took the time to post

Pew_Pew_Pew_Lasers!

See, panic over. Now all you need to do is ensure your battery is fully charged, as it will have taken a beating in the last week.

motorguy

Pew_Pew_Pew_Lasers! wrote: »

See, panic over. Now all you need to do is ensure your battery is fully charged, as it will have taken a beating in the last week.

Yeah its was the (a) stupidity and then (b) the spending of money unnecessarily to get it going again.

Good to have it up and running now. :beer:

epninety

bigjl wrote: »

We are all getting a bit to focussed on what is basically a theoretical point, does anybody know how much water it would need to hydraulically lock and engine, the water contaminated the fuel, so it is entirerly possible that the engine ran with more and more water being injected, with the engine running rougher each time.

How much water? Slightly more than the swept capacity of one cylinder divided by the compression ratio.

So for a typical 2L 4 cylinder car with 10:1 CR, that would be around 50cc of water.

The car will have started running rough due to water being injected, but not enough to cause hydraulic locking - fuel is injected at around 1:15 ratio with air *by mass* and 1/2 litre of air doesnt weigh much. A good portion of the contents will be blown out of the exhaust valve before the next injection, so it will take a while to get enough water into the cylinder to cause damage.

It's easily possible to pump in enough water when cranking to lock the engine, but since the engine is spinning on the starter it's very unlikely there is enough torque to damage anything. I've seen engines with faulty injectors and/or experimental ECUs which have locked during cranking because of the volume of fuel injected, never caused a problem.

dtaylor84

darich wrote: »

I wasn't aware that a) petrol was "compressible" and b) it was compressed in an engine.

Here was me thinking it was injected into the cylinder in a spray and ignited using the spark plug with the resultant explosion pushing the piston down.

I'd imagine that water in the tank may result in a few damaged components eg fuel filter, possibly spark plugs but unless the water is sucked in via the air filter in large quantities I'd wouldn't have thought there would be massive damage.

The spark plugs will be fine when they dry out. Water is produced as a product of burning petrol in oxygen anyway.

motorguy

dtaylor84 wrote: »

The spark plugs will be fine when they dry out. Water is produced as a product of burning petrol in oxygen anyway.

Yes, they had some surface rust on the diodes (?) but were cleaned up and put back in.

boyse7en

Glad you got it all sorted out in teh end.

It was fun reading the whole thread - its a brilliant example of why you shouldn't believe everything you read on the internet.
I haven't seen such a collection of nonsense, inaccurate theory and useful advice all in one place for quite a while

darich

dtaylor84 wrote: »

The spark plugs will be fine when they dry out. Water is produced as a product of burning petrol in oxygen anyway.

I realise that.
when hydrocarbons burn they produce CO2 and H2O....remembered frmo many years ago in chemistry!!!
Dam....I'm old!!!:D

Flying-High_2

boyse7en wrote: »

I haven't seen such a collection of nonsense, inaccurate theory and useful advice all in one place for quite a while

:T:rotfl::T