Water Crossings (Vehicle Preparation)

[Dedman]

So I am thinking of tacking some stupidly wet (potentially floating deep) tracks in Tasmania over summer and I want my forester to be as prepared as possible. I have decided to make a list of my preparations so others can reference as well as collect everyone else’s ideas and experiences.

Please post info on the following and remember to include your make and model;

1) Waterproofing engine

• I am particularly interested in how the electrics go under water/what people have done to improve them. (If don’t get information here I will experiment with submerging the engine before I change my oil next)
• Also interested in how sealed the ECU is/ if its likely to be damaged through submersion.

2) Water proofing other mechanical components

• eg diff or transmission breathers

3) Waterproofing cabin area

• What have you done to stop water from coming into the passenger compartment in the event of a long crossing or getting stuck in the water?

4) Damage that is likely to occur if the car is flooded in the event you get stuck in deep water

• Include critical damage that will stop you from driving home as well as other damage like cd player that may get destroyed but wont kill the car immediately

Here is what I have done so far (99 2.0N/A Forester, Manual, No airbags);

1) Waterproofing engine

• I have a snorkel that is water tight and have made sure all attachments/sensors to airbox/intake are sealed
• All leads are in good condition and engine doesn’t flinch with a good hosing
• Also have a fan cut off switch

2) Water proofing other mechanical components

• Diff breather with the outlet at the top of the rear gate

3) Waterproofing cabin area

• Sealed rear vents behind the rear bumper (a must for anyone who goes near water as they act as a pond storing water for months)
• Sealed holes in the floor (a floor bung was loose and previous owner had kindly drilled drainage holes)
• Sealed hole in spare tyre well (either bung was missing or there is just a massive drainage hole),
• Sealed up and holes/gaps in the firewall for cables etc.

4) Damage that is likely to occur if the car is flooded in the event you get stuck in deep water

• For not critical im guessing CD player/inverter/uhf/aircompressor would be destroyed
• Also the dash instrument/cabin fan probably would have future issues
• Not sure if there would be any damage that would not let you drive home (I don’t really know what controlling hardware is where in the car except for the ECU? mounted on the drivers side rear of engine)

Hopefully we can get a detailed list going for lots of different models so we are all prepared for the wet stuff :ebiggrin:

Also feel free to add water crossing tips and tricks you may have learnt along the way

 

[mr turbo]

You kind of touched on it in part 4, but one thing that is a must for longer &/or deeper water crossings would a fan cut off switch.

Another thing you might like to consider too is a tarp/blind for the front aswell :iconwink:

Regards
Mr Turbo

 

[dajeepman]

Water = bad

 

[Dulagarl]

Move the ecu. Mine is in the glovebox. If it gets wet there, it's the least of my problems.

 

[NachaLuva]

Move the ecu. Mine is in the glovebox. If it gets wet there, it's the least of my problems.

Do you know how they extended the wiring harness? I would love to do that!

 

[vincentvega]

I have a routine that works pretty well for me.

When I get to a crossing i pull to the side and let the engine run until the fans come on, and then go off. I then turn the engine off. There is now no reason for the fans to kick in since things are only going to get colder form this point.

I walk all crossings (with the exception of murky water in croc counrty!) and for anything deeper than bullbar height my water blind gets fitted as does my snatch strap which I wrap round my roof racks.

By now I have had time to properly asess the crossing and hopeully avoid doing something stupid Also my diffs, gearbox, wheel bearings etc have had a chance to cool down before hitting the water.

I then cross my fingers and give it a crack The key to surviving water crossings is preparation. If your strap is already fitted you can have mate hook up and drag you out of trouble before everything gets damaged.

A good blind that fits your car well makes a massive difference. I credit surviving a fairly wet cape york trip to the blind I had made up. I will try and find a pic of it for you but its basically a silver tarp wrapped around the nose of the car from the engine crossmember to the bonnet, marked up with a nikko and sewn to shape.

It sounds like you know your car pretty well. imagine your car with 10cm of water through it and think what would be water affected. If you are travelling in a remote area its fairly cheap insurance to carry a spare ECU, especially in a foz where they are mounted low. I carry a spare ECU for my lib even though it is mounted up under the dash. you never know!

 

[Dedman]

You kind of touched on it in part 4, but one thing that is a must for longer &/or deeper water crossings would a fan cut off switch.

Yep already done that, was in my list of mods under engine section

Water = bad

Good info... Do you want to share an experience?

Move the ecu. Mine is in the glovebox. If it gets wet there, it's the least of my problems.

Ok let me just check I know where the ECU is... It is the metal box attached to the rear of the engine on the drivers side of an ej20 and has 2 largish plugs (lots of wires) going into it yeah?
Assuming I am right about this being the ECU I have definitely got that soaked many times before as well a covered in steam, mud and the likes and havent had any issues. Are they really that vulnerable to water crossings? Being in the engine bay and all I would have thought that they would be very sealed but I would love to hear more of your ideas and opinions on the issue.

A good blind that fits your car well makes a massive difference. I credit surviving a fairly wet cape york trip to the blind I had made up. I will try and find a pic of it for you but its basically a silver tarp wrapped around the nose of the car from the engine crossmember to the bonnet, marked up with a nikko and sewn to shape.

Great info vincentvega. I had never thought of sewing a tarp into shape. Nice cheap way to get a good fit. I would also need a winch cable hole in it though
Also like the idea of carrying a spare ecu if they really are as prone to water related failures as people think (for $40 for a second hand one you cant really go wrong)

Also in terms of having recovery gear ready mine would be have the winch cable out and hope it works underwater well enough to get me to the other side (as I will most likely be doing this trip alone)

 

[NachaLuva]

If you are travelling in a remote area its fairly cheap insurance to carry a spare ECU, especially in a foz where they are mounted low. I carry a spare ECU for my lib even though it is mounted up under the dash. you never know!

Are ECUs interchangeable between cars, ie, will a 2nd hand one from an SF Foz fit ANY other SF Foz?

Ok let me just check I know where the ECU is... It is the metal box attached to the rear of the engine on the drivers side of an ej20 and has 2 largish plugs (lots of wires) going into it yeah?

Yep thats it...pretty vulnerable spot for something electronic & so vital

 

[Rally]

ECU is under the front passengers feet(firewall). They are not interchangeable unless you have the same mechanical set up and year model (generally). Depth of water is one thing- SPEED of the water is another thing altogether. Can be VERY BLOODY DANGEROUS.

 

[NachaLuva]

Depth of water is one thing- SPEED of the water is another thing altogether. Can be VERY BLOODY DANGEROUS.

Spot on! I have a whitewater kayaking background & can tell you water even only 12" deep can be impossible to stand in if it is moving fast. Fast flowing water only 2' deep can pin you against a log or rock under water making it impossible to lift your head above water against the flow.

I've never personally witnessed it but I've seen vids of fast flowing water ~3' deep pushing heavy 4WDs off a concrete ford. Would be funny if it wasnt so serious....

Fast lowing water should NEVER be underestimated!

 

[mr turbo]

Fast lowing water should NEVER be underestimated!

Spot on.

One rule of thumb I use is that if you can't stand up in it, with out being knocked over, due to it's flowing speed (what ever it's depth) you shouldn't be attempting to drive through &/or across it.

Regards
Mr Turbo

 

[Ratbag]

^ Actually, Mr T, if the water is flowing at a speed fast enough to even notice, one shouldn't attempt to drive through it. It doesn't take much speed on the part something as dense and heavy as water to push something as light as a car anywhere it likes ...

If one calculates out the force of water travelling at even one or two miles an hour, it's got a lot of energy ...

Most tsunamis we have all seen on TV show the enormous power of water moving at about a walking pace.

A car presents far more surface area to the water than your legs. Even if the water is only up to the wheel centre, the area presented to the water is about 4-6 square feet, or more. Think about it.

 

[Dedman]

^ Actually, Mr T, if the water is flowing at a speed fast enough to even notice, one shouldn't attempt to drive through it.

I think that is a bit of a conservative generalisation there Ratbag. You can absolutely safely cross water that you can obviously notice is moving if its not that deep. It just a matter of how fast vs how deep. If the car is at risk of floating then any current at all is going to cause issues. But in shallow water lower that the body work it can be going like hell and wont cause to many issues if it passes the walking test. Depths in between you will have to judge but some mild flow for most depths should be fine.
You also need to consider the risk of geting swept off course. For example a shallow causeway that has a meter drop on the done stream side I would be very hesitant to do with much flow at all. As part of your pre-crossing checklist you should always check the depth of where you might get washed if things dont go to plan/how you would recover from this.

I do think the walking test is a bit conservative though especially for our light low Subaru's.

As for the almost floating track im considering doing it is completely stationary water, not a river at all.

 

[Ratbag]

Gidday DmW

I think that is a bit of a conservative generalisation there Ratbag.

As one gets older one becomes more aware of all the "little" things in life that have one in their sights ... :iconwink: :lol:

You can absolutely safely cross water that you can obviously notice is moving if its not that deep. It just a matter of how fast vs how deep. If the car is at risk of floating then any current at all is going to cause issues. But in shallow water lower that the body work it can be going like hell and wont cause to many issues if it passes the walking test. Depths in between you will have to judge but some mild flow for most depths should be fine.
You also need to consider the risk of geting swept off course. For example a shallow causeway that has a meter drop on the done stream side I would be very hesitant to do with much flow at all. As part of your pre-crossing checklist you should always check the depth of where you might get washed if things dont go to plan/how you would recover from this.

I do think the walking test is a bit conservative though especially for our light low Subaru's.

As for the almost floating track im considering doing it is completely stationary water, not a river at all.

A quote for everyone:

"There are old pilots; there are bold pilots; But there are no old, bold pilots."

I am merely trying to ensure that every single person reading this thread is a bit more cautious than they need to be; rather than a little less.
Moving water is extremely dangerous, specially the sort of situation you referred to above (emphasised).

Here in Oz we have seen quite a number of fatalities recently arising from people not being careful enough. These are warnings well worth the repeating IMNSHO.

 

[thunder039]

i had 3 mates all loose there 4wds about a month ago crossing the mitchell river up at dargo luckily no one was drowned. i love water crossing but if water enters inside the cab consider everything stuffed including the electrics

if you cant walk it dont drive it

 

[idw]

Are ECUs interchangeable between cars, ie, will a 2nd hand one from an SF Foz fit ANY other SF Foz?

From what i understand no, the ecu from a 97 will work any other 97, ut and with an imobilizer either need to have all the imobilizer critical electrics as well or re coding. but i could be wrong.

I've considered encasing the ecu in a waterproof housing it looks like it'll fit inside an ally project box from jaycar, some rtv silicon and it's water proof. Not sure what other electrics need to be sealed.

https://www.jaycar.com.au/productResults.asp?MID=1&CATID=80&SUBCATID=987&keyform=CAT2

as for preparations for longer water crossings I've a small 1.2x1.8 tarp and a few straps to use as a car bra. lanolin (think thats what its called) is good for spraying all the electrics every few months. its wool grease works as a barrier to the water i think.

Not having a snorkel I've also poped off the air intake from the airbox on top of the manifold to stop water being sucked in for a crossing

 

[Ratbag]

^ Exactly the sort of thing that none of us want to see, or read about, Thunder.

Glad that all your mates were OK, but the loss of their vehicles has taught them a very expensive lesson ...

 

[idw]

As for the almost floating track im considering doing it is completely stationary water, not a river at all.

Welll put it this way, if you seal up to foz to be water tight when it does float just wack an outboard motor off the tow bar and motor down the river

 

[taza]

ECU's are not interchangable.

The one on the SF N/A i mounted on the back of the engine block and is 100% water tight.
SG, Outback's and so on(Yes even EJ20 impreza's) are mounted either in the passengers footwell or under the dash depending.

I personally hate water crossings, I've even gone off mud quite abit.
The damage and danger they can cause is unbelievable. Having seen a few cars washed away and or drowned it has completely put me off.
I'd hate to have my car fill up with water and wreck everything. To start off with the easiest things to go include; Engine(for me a rebuilt 2.5 donk, $3500), Piggyback Comp($500), Stereo(inc; amps, speakers, sub $1200+), A/C/Blower motor, starter, alternator, etc... It could quiet easily add up to $7000+.
All due to a stupid mistake or silly decision. Sure it might be fun and cool, and I do like water crossings but to me the risk isn't worth it.
I'd rather do some trails, rocks, sand dune, beach work, crawling, donuts or what ever else instead.

If you do wanna do these crossings by all means go for it, just walk it first and attempt so at your own risk.

Using a blind infront is a very good idea along with a snorkel. Putting vasilne on plugs and connections will stop water penetrating them.

Always take a few cans of WD-40 with you and some basic tools. Always have the tools to remove the spark plugs just incase you get water in the engine, then you can atleast get it out by cranking without the plugs in there. You could possible save an engine or be able to drive it with a bent rod. I know Kevin on hear hydro locked his first motor in his Foz.

Oh and lastly always video any and all water crossings!!! This is by far the most important :iconwink: You can then show off your awesome crossing/s or show us your epic fail/drowning. Either way good entertainment

 

[Dedman]

i had 3 mates all loose there 4wds about a month ago crossing the mitchell river up at dargo

Please tell me that they wernt traveling together....

Welll put it this way, if you seal up to foz to be water tight when it does float just wack an outboard motor off the tow bar and motor down the river

:rotfl:I was actually thinking of getting the oars out:rotfl: