MG4 would seem to have made it through a flooded ford

[JonnyG]

Any link to that? I couldn't find it.

Edinburgh couple fume as they are handed £17K bill by Tesla as they 'drove in rain'

The pair have told of the "excruciating stress" that has been caused by the ordeal, with Tesla allegedly demanding they pay for the battery that stopped working after a drive in the rain.

www.edinburghlive.co.uk

 

[Rolfe]

Ta.

 

[Alb]

Can anyone enlighten me what it is about the flood water that causes the ICE cars to drown? I believed it was water being sucked into the tail-pipe, which you could prevent by never letting the engine fall into idle while driving through the water, but in another thread here a bunch of people told me that was nonsense. So what exactly is the fail point? It was slightly disconcerting to see several cars appear to make it, but then grind to a halt in obvious deep trouble shortly after emerging from the water.

How repairable is the damage? Are these cars going to be OK with a little drying-out, or are they write-offs, or what?

The most likely failure is hydrolock.
The engine air intake sucks in water instead of air. As water isn't compressible, once it's in the cylinder the piston will stop dead. Unfortunately the conrods and crankshaft carry on moving so the conrod will end up bent. It's terminal for the engine.

 

[Tonych]

Can anyone enlighten me what it is about the flood water that causes the ICE cars to drown? I believed it was water being sucked into the tail-pipe, which you could prevent by never letting the engine fall into idle while driving through the water, but in another thread here a bunch of people told me that was nonsense. So what exactly is the fail point? It was slightly disconcerting to see several cars appear to make it, but then grind to a halt in obvious deep trouble shortly after emerging from the water.

How repairable is the damage? Are these cars going to be OK with a little drying-out, or are they write-offs, or what?

Initially it's the exhaust getting blocked stopping the engine. But water getting into the electrics and engine itself are all bad news.

 

[Rolfe]

The most likely failure is hydrolock.
The engine air intake sucks in water instead of air. As water isn't compressible, once it's in the cylinder the piston will stop dead. Unfortunately the conrods and crankshaft carry on moving so the conrod will end up bent. It's terminal for the engine.

Initially it's the exhaust getting blocked stopping the engine. But water getting into the electrics and engine itself are all bad news.

Hell's bells, that's bad. And they drive the cars at that flood like they think they can make it through on momemtum! I was always told, if you have to risk it (and don't even think you can risk it if the water is more than about a foot deep) then go as slowly as you can while still keeping the engine driving the car. I can see how that might keep the exhaust somewhat clear, but not how it can protect the air intake.

All that rushing at the flood with a bow wave is going to make it more likely that the air intake turns into a water intake, right? Why on earth would anyone even start to drive through that? I can't even imagine.

I think the MG4 driver was mad too, but the risks there seem more to do with the car losing traction due to the depth of the water (not sure if it did that, when lighter cars didn't) and the damn undertray warp giving it a good chance of getting ripped off.

 

[Tonych]

Hell's bells, that's bad. And they drive the cars at that flood like they think they can make it through on momemtum! I was always told, if you have to risk it (and don't even think you can risk it if the water is more than about a foot deep) then go as slowly as you can while still keeping the engine driving the car. I can see how that might keep the exhaust somewhat clear, but not how it can protect the air intake.

All that rushing at the flood with a bow wave is going to make it more likely that the air intake turns into a water intake, right? Why on earth would anyone even start to drive through that? I can't even imagine.

I think the MG4 driver was mad too, but the risks there seem more to do with the car losing traction due to the depth of the water (not sure if it did that, when lighter cars didn't) and the damn undertray warp giving it a good chance of getting ripped off.

Got to agree. We had a ford in the village I was brought in and I often had to drive through it as a learner. I was told go fast enough to create a small bow wave - and if you can, follow someone else!

 

[Rolfe]

There's a ford in the river here, but I have only ever gone through it on horseback.

Until relatively recently satavs were bringing cars this way, because it saves a couple of hundred yards over taking the bridge that carries the main road. I don't believe anyone actually attempted to drive through it though, they just swore a bit and did a 3-point turn.

I think Land Rovers can do it OK, but anyone trying it in a normal car even on a day like that pictured would have a screw loose. What it's like right now is left as an exercise for the imagination of the reader.

 

[dsimpkins]

Here are my thoughts in relation to some of the replies to this thread, sorry if it's a bit TLDR (Too Long Didn't Read)

Petrol vehicles, the ignition circuit can short in water causing the engine to die. Usually by the fan behind the radiator spraying water over the HT leads.
Diesel and petrol vehicles, hydrolock by sucking water into the engine, or exhaust getting blocked with water (keep the engine revs up)

Land Rovers and other 4x4s can still suffer from this too, but the higher ground clearance plus driving technique are the key to wading. Yes, you can get raised air intakes or snorkels for these vehicles. There is a subtle difference. Raised air intake is used to raise the air intake, typically used in dusty/desert conditions to reduce amount of dust/sand sucking into air intake. Not waterproof. Snorkel, also raises the air intake, but is waterproof, and can be used to wade deeper water. Plenty of 4x4 owners out there with raised air intakes that think they can safely wade in water as they don't know the difference.

The key thing is driving technique. Not too fast, and not too slow, but enough to create a bow wave. This will cause the water to be higher at the front, but is then lower than the actual water level around the front wheels allowing a vehicle to wade through water deeper than the vehicles maximum wading depth (0.5 metre for a standard Land Rover Defender)

However, this ford is in flood, which means the water flowing through it is flowing faster than it normally would. Water doesn't have to be very deep at all to lift a car if it is flowing fast enough. The MG4 demonstrates this, and was definately floating at one point, but either it took on more water and sank, or hit some higher ground and regained traction.

Other potential hazards with flood water, you do not know what is in the water, you could hit a large tree branch, rocks, etc washed downstream. Flood water should be treated the same as raw sewage as sewers and drains will have overflowed in the flood. If the flood is on a road rather than a ford, then drain covers could have lifted, and if your wheel drops into one of those, then you're stuck. If you have to walk in flood water, then an open drain would suck you in and that would be it.

From the training I have the guidance is clear, do not drive or wade in flood water. Find an alternative route. There are too many examples of people losing their lives as a result of driving through flood water. Even experienced drivers can be caught out. For example, there was a lady who drove through a ford in her Land Rover every day, but drove through while it was in flood. Her Land Rover was swept away, and found 5 miles downstream wedged against the side of a bridge. Unfortunately she drowned.

As far as I'm concerned, every driver going through that ford in flood is an idiot.

 

[Rolfe]

Thanks for all that, really interesting. I was taught the not-too-fast-not-too-slow technique too, and to keep the engine revs up, but never had it explained about the air intake. And that's all very well for maybe a foot or so of standing water, but even trying that ford suggests a screw loose on all the drivers. What that bin lorry driver thought he was doing I have no idea.

I remember just once, standing water on the A702 one morning, and a car actually stopped in it on my side of the road. I thought about it, didn't seem too deep, and knowing the lie of the land it seemed highly unlikely there were any obstacles on the road. Also, it seemed slightly shallower on the right-hand side of the road. I pulled out and went for it, not-too-fast-not-too-slow, keeping the revs up on my automatic gearbox by steady acceleration, and made it through. Wasn't much more than a foot though, and there was no running water.

I'm surprised if the MG4 really did float at one point. It certainly looks like it, but then I wondered if it was an artefact of the way the camera was moving. It's odd that it would do that when lighter cars didn't appear to do it. But that is surely a serious concern if there's any current - that even if you do it right and your engine doesn't cut out, you could be swept away. And even if you were only swept into these hand rails, and they held, that would be quite enough trouble.

 

[TheHypnoToad]

Initially it's the exhaust getting blocked stopping the engine. But water getting into the electrics and engine itself are all bad news.

If the air intake is above the water, then water in the exhaust will be OK, as it won't be totally blocked by the water - for example the air intake on this is a snorkel going to the top of the windscreen:

 

[Rolfe]

The water is half way up the damn windscreen. Where is the air intake?

I can't stop watching that original video. It's absolutely mesmerising the way driver after driver just throws his car into the water with gay abandon. Sometimes it even looks as if they've been advised not to do it, but they shoot off anyway.

The MG4 driver isn't any better, he just gets away with it! It's hard to see the water level as the gauge isn't shown when that car goes through, but I think at the higher end of the range shown, which would be almost three feet. Absolute madness.

 

[TheHypnoToad]

The water is half way up the damn windscreen. Where is the air intake?

It's the big black tube that zip-tied to the side of the windscreen, there are also some green electical cables for the roof light next to it. Around 4.25 in the video it's easier to see This will be an aftermarket extra btw, I wouldn't recommend doing this in a regular 4x4 !

 

[Rolfe]

Oh, I see it now. A sort of DIY snorkel. Someone doing a demo, that much was obvious. The police were at least allowing it, if not actually driving it.

I saw a video about an electric vehicle driving underwater somewhere in Australia - a strait that had been tried in modified ICE vehicles before but without success. The specially-built EV succeeded, with drivers I think taking turns to go up and down to drive it in relays.

 

[dsimpkins]

It's the big black tube that zip-tied to the side of the windscreen, there are also some green electical cables for the roof light next to it. Around 4.25 in the video it's easier to see This will be an aftermarket extra btw, I wouldn't recommend doing this in a regular 4x4 !

The green cables may be raised breather tubes for the engine, gearbox, transfer case, and diffs. On a Land Rover these normally terminate just below the underside of the bonnet. Wading that deep would allow water to get into the oil of those components turning the oil into a creamy sludge.

They clearly were interested in having fun, with total disregard for anyone else. Did you see the spectators on the footbridge getting soaked by the waves they created when they "doubled up".

This sort of behaviour should be kept to "pay and play" off road sites, and not the public highway. Just damages the reputation for other 4x4 owners that have respect for other road users.

I can't express how I really feel about those drivers in the Kenilworth video as it'd probably result in me being banned by the mods

 

[Corindikev]

Oh, I see it now. A sort of DIY snorkel. Someone doing a demo, that much was obvious. The police were at least allowing it, if not actually driving it.

I saw a video about an electric vehicle driving underwater somewhere in Australia - a strait that had been tried in modified ICE vehicles before but without success. The specially-built EV succeeded, with drivers I think taking turns to go up and down to drive it in relays.

That was across Darwin Harbour and it was a specially built electrically powered old 1970s land cruiser.

 

[Corindikev]

Most of those drivers who attempted the ford were complete idiots. I train 4WD drivers for the NSW SES & dsimpkins post #28 is on the money.

 

[Rolfe]

That was across Darwin Harbour and it was a specially built electrically powered old 1970s land cruiser.

I watched quite a long video about it a few months ago. Absolutely amazing.

 

[tsedge]

EVs are inherently better at wading and some makers test for it - eg Nissan Leafs have long been known for 700mm wading depth (the same as many 4x4s).

Here's a short test video, also showing how to create the right bow wave by driving consistently at a steady speed.

I'm not saying I'd do this - it can still be bad for the long-term health of the car - but it shows what can be done.

 

[dsimpkins]

Most of those drivers who attempted the ford were complete idiots. I train 4WD drivers for the NSW SES & dsimpkins post #28 is on the money.

Thanks @Corindikev. I volunteer for our local 4x4 Response group, and our training is very clear and specific on water. DON'T GO IN. If we were to get stuck then that's just someone else that needs rescuing, tying up vital emergency services time, and risking further lives.

I get that it's fun, but the people in the second video are just idiots, and an accident waiting to happen. If you want to play, go somewhere set up for it. I've been wading, but in a controlled environment, with help on standby.

What's the wading depth of an MG4, anyone know? I doubt it's 700mm, and the gearbox breather is already problematical. Unless it's raised to a suitable height, the gearbox of the MG4 in the first video will now be full of water.

 

[Tonych]

Here are my thoughts in relation to some of the replies to this thread, sorry if it's a bit TLDR (Too Long Didn't Read)

Petrol vehicles, the ignition circuit can short in water causing the engine to die. Usually by the fan behind the radiator spraying water over the HT leads.
Diesel and petrol vehicles, hydrolock by sucking water into the engine, or exhaust getting blocked with water (keep the engine revs up)

Land Rovers and other 4x4s can still suffer from this too, but the higher ground clearance plus driving technique are the key to wading. Yes, you can get raised air intakes or snorkels for these vehicles. There is a subtle difference. Raised air intake is used to raise the air intake, typically used in dusty/desert conditions to reduce amount of dust/sand sucking into air intake. Not waterproof. Snorkel, also raises the air intake, but is waterproof, and can be used to wade deeper water. Plenty of 4x4 owners out there with raised air intakes that think they can safely wade in water as they don't know the difference.

The key thing is driving technique. Not too fast, and not too slow, but enough to create a bow wave. This will cause the water to be higher at the front, but is then lower than the actual water level around the front wheels allowing a vehicle to wade through water deeper than the vehicles maximum wading depth (0.5 metre for a standard Land Rover Defender)

However, this ford is in flood, which means the water flowing through it is flowing faster than it normally would. Water doesn't have to be very deep at all to lift a car if it is flowing fast enough. The MG4 demonstrates this, and was definately floating at one point, but either it took on more water and sank, or hit some higher ground and regained traction.

Other potential hazards with flood water, you do not know what is in the water, you could hit a large tree branch, rocks, etc washed downstream. Flood water should be treated the same as raw sewage as sewers and drains will have overflowed in the flood. If the flood is on a road rather than a ford, then drain covers could have lifted, and if your wheel drops into one of those, then you're stuck. If you have to walk in flood water, then an open drain would suck you in and that would be it.

From the training I have the guidance is clear, do not drive or wade in flood water. Find an alternative route. There are too many examples of people losing their lives as a result of driving through flood water. Even experienced drivers can be caught out. For example, there was a lady who drove through a ford in her Land Rover every day, but drove through while it was in flood. Her Land Rover was swept away, and found 5 miles downstream wedged against the side of a bridge. Unfortunately she drowned.

As far as I'm concerned, every driver going through that ford in flood is an idiot.

Brilliant summary - I have experienced all of that while learning to drive. I learned in a Hillman Hunter with dodgy electrics so large puddles, and even a heavy sneeze would stop the ignition from working, so driving through a ford just slowly enough to stop water hitting the coil and plugs was fun for a teenager (who always carried WD40)