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Old 30th June 2005, 15:58   #1
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Question Hydrostatic Lock - Water inside the engine

Hi,

The following is an excerpt from the site
"http://www.car-forums.com/archive/t8933.html"

Its an interesting write up on Hydrostatic locks... It describes what
could happen if we go thru water thats high enough to get sucked into the air intake.

###########################################
"Water lock" is the familiar term for the condition known as hydrostatic lock. As referenced in your question, it occurs when water is ingested by the engine in a certain quantity. The specific quantity necessary varies by engine. The problem is one of basic physics -- liquids are non-compressible. Water, of course, is a liquid.

Your engine is a four-stroke-cycle engine. The four "strokes" are intake, compression, power, and exhaust. Note that compression directly follows intake. The intake stroke occurs during (generally) downward movement with the intake valve open. This causes an air-gas mixture to be drawn into the cylinder. At the bottom of the intake stroke, the cylinder volume above the piston is at its greatest. During the compression stroke, the piston moves upward, reducing the cylinder volume above the piston until the piston reaches its upper travel limit. At this point, the cylinder volume is at its smallest. Under normal conditions, the air-fuel mixture is basically gaseous in nature and is therefore compressible. But... what happens if the cylinder is contains liquid instead of vapor? In this case, at the point when the cylinder volume is reduced to where it is approximately the same as the volume of liquid in the cylinder, the piston will no longer be able to move upward. This is the "lock" point.

Depending upon specifics of operating conditions, engine design, and general engine health, this sudden stopping of the piston by a non-compressible mass can cause damage such as a broken piston, bent or broken connrod, shattering of engine castings, or even breakage of the crankshaft.

As to the question of how much water is needed? Not much -- when the engine ingests into any single cylinder a volume of water greater than the cylinder volume above the piston at TDC, the piston in that cylinder will be stopped on its compression stroke when the cylinder volume above the piston matches the volume of ingested liquid. The smaller the engine (displacement), the less liquid is needed to get to this point. That amount can be roughly calculated for any given engine, so long as the bore, stroke, and compression ratio are known.
###########################################

My question....

The air intake of the diesel engine in my contessa is placed pretty low down behind the right headlight. As a result, I am afraid of the possibility of it sucking in water with the air when I travel through submerged areas.. and there are a lot of them on my way to work... Marol is among the worst!!!

Now in the case of a petrol engine, assuming I did not break anything... I could just remove all the spark plugs and crank the engine. This would eject all the water out of the cylinders. A lil spray of WD40 into each cylinder, put the plugs back in and I could drive my vehicle back home or to the garage.

Diesels don't have any spark plugs.... so... is there any way that we can get the water out of a diesel engine without having to take the head off ???
What about the glow plugs... has anyone ever replaced them ? if we remove them, does it open into the cylinder chamber ? and how easy is it to get them out ?

Regards,
Ashley
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Old 30th June 2005, 17:32   #2
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when my indica glow plugs died, the dude just opened then using a spanner and replaced them. So removing them is an easy task. They should be opening into the cylinder chamber because their function is to heat the air fuel mixture to facilitate compression ignition.
As for the intake, there used to be an old mahindra jeep i saw in which the owner had raised the intake by attaching a rubber hose it and pulling it out near the windscreen. Since lot of driving was thorough deep water in villages, he went for that option, i suggest you do the same if you wade through deep water regularly.
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Old 1st July 2005, 17:25   #3
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Man, the moment you get wate into the engine
Even if you think you have drained out every last drop-
(which i dont think will be possinle)
Stop. Dont move the car under its own power for a minute
You should lubricate cyliner piston walls if you can
Call a tow truck and take it to the garage

There will still be water there
also in that case water may have gone into you sump & Lub oil, (engine oil)
which if you run the engine will then mix with the oil and the sump and the lubrication will go south,
you will proceed to destroy all you bearings etc
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Old 4th July 2005, 18:27   #4
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The probability of an engine sucking in water is rather remote despite the fact that the restrictor is situated in the confines of one of the fenders, depending upon engine placement. For an engine to suck in water even whilst submerged, on suburban roads is a far fetched idea.
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Old 5th July 2005, 11:24   #5
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True, Ususally the engine would die first the moment the air pipe got submerged before it could create enough vacuum to suck in the water

Water in the engine so far, i've only heard of due to bown gasket
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Old 15th July 2005, 17:00   #6
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Quote:
Originally Posted by Revvhead
Man, the moment you get wate into the engine
Even if you think you have drained out every last drop-
(which i dont think will be possinle)
Stop. Dont move the car under its own power for a minute
You should lubricate cyliner piston walls if you can
Call a tow truck and take it to the garage

There will still be water there
also in that case water may have gone into you sump & Lub oil, (engine oil)
which if you run the engine will then mix with the oil and the sump and the lubrication will go south,
you will proceed to destroy all you bearings etc
Thanks Revvhead!

Well, the only time I did get water mixed in my Engine oil and Gear oil was with my M800.
It was the monsoon of 1999, office closed early cause of flooding in bombay and I had to drive home thru really deep water.
Water levels outside were as high as half my door height (thats nearly the top of the bonnet) and inside the car, there was water over the bottom of the seats...
Me and 3 other guys with me still find it hard to believe we made it home thru that deep water without stalling even once. We were very lucky!

Come to think of it now... the water was pretty high, but didnt get sucked into the air intake.

Took it to the garage the next day to get it washed (the gutter water made it stink inside!!!) and thats when we discovered that water had gotten into the engine oil and the gear oil... both were milky white.
Had both flushed with flushing oil and then put in fresh oil...
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Old 17th July 2005, 20:55   #7
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Hey, what happens if you go really slow thru deep water, and it goes into your muffler section?? My OHC has pretty low ground clearance and it has a crack in its middle tail pipe section(which sounds pretty cool, actually...!! Need to get it fixed), and a couple of days back I was wading thru deep water on 100 feet road, and the car would just not respond... I had to keep revving the engine, and after about 2000rpm, the engine would barely respond... and it felt REALLY sluggish.
My questions are:
1 will the back-pressure created in the exhaust also be able to keep the water out, or will it help suck it in?
2. What happens if water gets into the tail pipe...?? will it evaporate and turn into steam due t the temperature of the exhaust gases and corrode the pipe really quick, or what??
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Old 17th July 2005, 23:30   #8
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In our conditions, water vapour is enough to corrode silencers. Commonly visible on many cars, esp Hyundais.

In water of any depth over 3 inches, keep the car revved high. This will create enough exhaust pressure to force water outwards. It's a tried and tested trick.
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Old 18th July 2005, 14:18   #9
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Yeah, thats what I tried doing, but by the time i realised tat the water was that high, the engine was barely responding. Luckily i managed not to stall the car...
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Old 18th July 2005, 14:49   #10
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Quote:
Originally Posted by aveek
a couple of days back I was wading thru deep water on 100 feet road, and the car would just not respond... I had to keep revving the engine, and after about 2000rpm, the engine would barely respond... and it felt REALLY sluggish.
A link that was posted on another forum that I am a member of...

http://www.offroaders.com/info/tech-...r-crossing.htm

Do read the entire article, its quite informative.

The article states
... But if you do strike problems avoid using the clutch as this may allow water to get between the friction plate and the flywheel, resulting in limited drive. ...

I think this is what might have happened to you when you say "the engine would barely respond... and it felt REALLY sluggish"

I myself have encountered this situation but till reading this article, could not pin point the cause of the loss in power to the wheels!
The engine would race, the clutch was fully released, but the car would not move....
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Old 18th July 2005, 16:06   #11
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Water getting b/w the clutch and flywheel would result in loss of friction grip, leading to a situation much like clutch wear, where the engine revs freely, but the car doesn't move. The engine itself wouldn't become sluggish.
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Old 30th July 2005, 17:07   #12
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This thread is going to come back to life especially after the mad rains in Bombay over the past few days. Offtopic, but today I'd gone to ASS for regular oil change of Honda & saw quite a bit of cars. They said they weren't taking cars for oil change & I asked why, he said that there were 190, thats right 190 Honda's (city's & accord's included) which had various problems due to excessive rains!
Just for the record, our CRDi managed to wade through almost window high water without stopping, thanks to the car & our driver. Dad superbly impressed with Hyundai.

Last edited by RJK : 30th July 2005 at 17:10.
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Old 4th August 2006, 14:18   #13
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Guys could you tell me how to handle an A/T in similar conditions?
Thanks
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Old 9th September 2006, 00:19   #14
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This topic was about water so i thought i ll ask my question as it about water and air filter.
I just opened the bonnet of my car day before and i saw that little water was present in the air filter ka intake.If was like in very very minute proportion.I cleaned it with a cloth but.my question is how come the water entered the mouth of the air filter and if it is in very minute quantity will it cause any harm to the engine anyhow if i had not seen and cleaned it ?
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Old 9th September 2006, 04:32   #15
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Removing water for once?.... how about... putting the car in say 3rd+ gear and pushing the car backwards manually... ...

*just a thought...

Last edited by SLK : 9th September 2006 at 04:42.
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