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Author Topic: Why Does Wifeys Car Engine Get Flooded ?  (Read 16839 times)

neilep

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Why Does Wifeys Car Engine Get Flooded ?
« on: 22/02/2008 01:49:47 »
Dear Auto Aristocrats,

Typical..........the ocean is 60 miles away and wifey still parks the car in it !

It's engine is well flooded !!





Having said that....the engine has flooded twice before.

Wifeys car is an automatic Toyota Yaris...on two occasions she has started it from cold to just move it a few feet ....so...the car has only been on for twenty seconds or so !....why should this flood the engine ?...and also...what exactly is a flooded engine ?...flooded with what ? petrol ?...oil ?...air ?...peanut butter ?

I don't know.....but ewe do !!

thanks



neil






Soul Surfer

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Why Does Wifeys Car Engine Get Flooded ?
« Reply #1 on: 22/02/2008 10:38:02 »
Not sure that modern car engines can get flooded.  I don't think that many cars use carburettors these days they are all fuel injection devices.

A carburettor was a device to control the fuel intake for the engine it operated by using the suction from the inlet manifold to pull a spray of fuel droplets mixed with air into the cylinder nowadays the fuel is injected directly from a metered pump usuall into the inlet manifold but sometimes directly into the cylinder like a diesel engine.

To ignite properly with the sparking plug the fuel air mixture must have the correct balance too much or too little fuel it will not ignite.  Now when car engines are cold they need a bit extra fuel to work.  This was done using a choke which effectively increased the suction when the engine was cold.  Too much choke and the mixture would get to rich in fuel and no ignite properly that is called flooding the solution was to stop the choke and turn the engine over with the starter a few times to clear the excess fuel.

« Last Edit: 22/02/2008 10:39:41 by Soul Surfer »

Karen W.

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Why Does Wifeys Car Engine Get Flooded ?
« Reply #2 on: 28/02/2008 23:11:31 »
My husband worked in a dealership for a long time and said they had many vehicles come in with this problems.. He said no guarantee, But it sounds just like this!

 "I worked in a jeep, (SUV)dealership's service department. We were also responsible for some Renaults. This reminds me of something that sometimes happened to Renaults."

  "Someone would start their car, probably when it was cool outside, (its always cool out here), quickly move it a few feet , and quickly shut off the engine." "Because it was cold the computer made the mixture being drawn into the cylinders VERY fuel rich."
 "It would do this until it warmed up to operating temperature because the engine was shut off in a very few seconds, and this VERY fuel rich mixture had the effect of washing the oil film off of the piston cylinder wall off and causing very low compression." "So low it would not start later." "Good combustion requires correct fuel/air mix, compression and spark."

"PS. To start these things, the technician would  squirt  motor oil directly into the cylinders through the spark plug hole, after removing the plugs. Then reinstalling the plugs and turning the engine over with the starter until it began to run, in the process creating a spectacular cloud of blue smoke!"

"The problem can be further avoided by not shutting the car off so quickly give it at least 30 seconds to a minute to run and get the pistons lubed before turning it off, especially for just a quick move like that! Always run it a little after starting to avoid that oil wash off.'


 
« Last Edit: 28/02/2008 23:15:40 by Karen W. »

another_someone

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Why Does Wifeys Car Engine Get Flooded ?
« Reply #3 on: 29/02/2008 01:41:20 »
My mother has exactly this problem with her Audi A6, so if she has to move it a few feet, she will drive it around the block, and then park it the few feel away, to avoid just this problem.

almoagnadna

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Why Does Wifeys Car Engine Get Flooded ?
« Reply #4 on: 23/12/2009 14:44:00 »
I just took my 2009 Yaris (purchased in July) into the Toyota dealership because - as it appears - the exact same thing happened to me.

I had to dig pretty deep to get any sort of information out of them, but they eventually spoke to my boyfriend (*sigh* to stereotypes) and said the Yaris is particularly prone to a flooded engine like this.  No further explanation was given, but Karen W's explanation seems to be fitting.  The night before, I'd moved the car from the driveway into the garage, and had likely caused it then. 

I at least don't feel so bad driving back out to the dealership to pick it up now, knowing that I've got measures to prevent it in the future. 

Thanks, all!

neilep

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Why Does Wifeys Car Engine Get Flooded ?
« Reply #5 on: 23/12/2009 15:41:01 »
That's wicked almoagnadna,

Wifeys yaris verso is a few years old...nice to see that Toyota have not solved the problem !!  ::).....besides that....it's the most reliable car we have ever had....mine's a toyota too !  :D

graham.d

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Why Does Wifeys Car Engine Get Flooded ?
« Reply #6 on: 23/12/2009 16:58:41 »
I used to have a bmw530i and it used to do this. I just had to move it for the window cleaner, so started it, moved it a few feet and stopped it. I then remembered I had to go on an errand and the thing would not start. I called out BMW (free support service) and they came after about 10 minutes and just kept on cranking the starter motor until it started. They said it was a common problem. It had a fuel injection system.

I think the electronics gets fooled and pumps in a very rich mixture. If spark gap in the plugs get sufficiently wet with fuel the spark won't happen. The fuel has to evaporate off sufficiently.

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Why Does Wifeys Car Engine Get Flooded ?
« Reply #7 on: 24/12/2009 01:32:20 »
Yup. Spark plugs don't work very well when they are wet with petrol.

It's not a good idea to only run a carmobile engine for a few seconds. The rich mixture left in the cylinders washes the oil off the cylinders (as someone already pointed out,) so the next time you start the engine, the cylinders and pistons move without much lubrication, and that can result in some wear.

It's best to warm up an engine once started, and the best way to warm it up is to get moving gently down the road. Trying to warm up an engine while the car is not moving is not good either. It takes a long time, and during that time the oil is too viscous to do a good job of lubricating the engine.

graham.d

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Why Does Wifeys Car Engine Get Flooded ?
« Reply #8 on: 24/12/2009 09:56:11 »
"[...] during that time the oil is too viscous to do a good job of lubricating the engine."

Not true with the new synthetic oils though.

neilep

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Why Does Wifeys Car Engine Get Flooded ?
« Reply #9 on: 24/12/2009 12:39:07 »
Will it not fix itself if just left for say 30 minutes or an hour ?

SeanB

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Why Does Wifeys Car Engine Get Flooded ?
« Reply #10 on: 24/12/2009 16:23:08 »
If left for a few hours most of the fuel will vaporise, if the ambient temperature is high enough. This problem is worsened on older vehicles in that the injectors can leak with wear and time, and flood the cylinder with a lot of fuel, that stays a liquid as there is too much, preventing starting. There is enough pressure in the fuel line to flood any cylinder so that it will be very hard to start, and can be dangerous to your catalytic converter by flooding it with unburnt fuel, which it will burn very rapidly on the next start, either overheating and melting, or setting fire to grass under the vehicle in worst case.

As to the lubrication, synthetic oils are lower viscosity, but they are still washed off the cylinder walls by fuel. The main reason for using them is to lower internal friction in the engine, and to enable tolerances to be made smaller and running speeds higher without metal on metal contact. These oils still depend on a pump to get the pressure up, and it still takes some time for the pressure to get the flow to full levels, especially in the head and the crankshaft, which are at the ends of a long oil flow path, restricted by a oil filter along the way that has to fill up first.

Geezer

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Why Does Wifeys Car Engine Get Flooded ?
« Reply #11 on: 24/12/2009 20:18:57 »
If left for a few hours most of the fuel will vaporise, if the ambient temperature is high enough. This problem is worsened on older vehicles in that the injectors can leak with wear and time, and flood the cylinder with a lot of fuel, that stays a liquid as there is too much, preventing starting. There is enough pressure in the fuel line to flood any cylinder so that it will be very hard to start, and can be dangerous to your catalytic converter by flooding it with unburnt fuel, which it will burn very rapidly on the next start, either overheating and melting, or setting fire to grass under the vehicle in worst case.


That's a very good point. I have witnessed a situation with a carburetted engine where so much fuel was dumped into the silencer (muffler) that when the engine actually did fire, the fuel in the silencer exploded and blew the silencer apart.

It's always a good idea to warm up an engine as quickly as possible so that it reaches its optimum working temperature in the shortest possible time. The best way to do that is by driving it (gently). Apart from inadequate lubrication, while the engine is cold, the fuel/air mixture will be rich. If it was up to me, those remote starter things for warming up your car would be banned in the US. Are they even available in the UK?

 

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