Although the hope is not to encounter anything deeper than a dribble - if we find ourselves 100km down a piste - with 20km to go - and faced with something more substantial than a stream - what depth do you reckon I could drive the BMW 525 through??

And perhaps more importantly any hints/guides on how to manage it with a greater level of success.

I assume its petrol?

1st you need to source the level of the air intake. you DO NOT want to take on water higher than this. Water sucked through into the engine will kill it (most likely). Now you could fashion a snorkel for it if so inclined. This would also help to reduce the amount of sand/dust particles reaching your filter. Just extend it to a high point.

Back to petrol - I am not particularly clued up on this as a deisel LR owner but you need to waterproof the electrics under the bonnet including the dizzy and ignition coil? some other bits too but im not sure. if they get a sniff of moisture they will cut out. best to waterproof using vasaline and latex gloves with elastic bands over the dizzy.

you could also fit a cut out switch to the fan, i assume its electric not viscous? stop the fan before entering the water as it will chuck up water all over your electrical bits and cut out your engine.

alternatively. turn off the engine and get someone to tow you through! I towed a few mobile homes through flowing oueds in my Land Rover 90 back in October that was on tarmac roads though.

Hope this helps.

G

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I found the following link which may help you: Waterproofing a Petrol Engine [Archive] - Land Rover UK Forums

related to petrol land rovers, but the same principle applies.

I also forgot to mention raising the breathers from the axles and gearbox (if you have any) as water may get into these and emulsify your oils. extend these by pushing pipe onto the existing ones and raising it up higher.

(mine are up to the roofline with the snorkel ) maybe a bit excessive for your 525!

attached pic of my 90 in action (the river was nearly 4ft deep in the centre )

Attached Images

 

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Cheers Griff - I have done some reading - and reckon we will be OK up to about 15cm - and pushing it at 20cm.

We walk across any crossing to check the depth - and condition of the surface - before deciding what to do.

It is bad enough that I have ordered a South African spec sump guard - and will be buying metal tonight to build fuel pipe and tank protection.

If it is deeper than 20cm - we will head back the way we came

20cm doesn't sound very deep. I drove my AX through water approx. twice that. (Mebbe a little less)

My rather unscientific method (based on nothing but my own supposition) was to drive through slowly to minimise any bow wave and keep the engine revving reasonably high but on the clutch to keep the exhaust gasses pumping. As long as you don't actually submerge it, my suspicion is that most engines can take a fair bit of water spray. This was, however, standing water. I expect fast flowing water might be a bit more difficult.

Ah, that poor AX... the things I put her through... (bloody great car by the way! )

Matt

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*Disclaimer* - I am not saying my bike is better than your bike. I am not saying my way is better than your way. I am not mocking your religion/politics/other belief system. When reading my post imagine me sitting behind a frothing pint of ale, smiling and offering you a bag of peanuts. This is the sentiment in which my post is made. Please accept it as such!

You do want to go fast enough to create a bit of a bow wave because it means its pushing the water away from the vehicle. You just don't want to charge in. Your more interesting challenge with fording rivers in Africa is it depends where as there are significant parts where you probably aren't going to want to wade through first because of the risk from local wildlife. The only thing you can do then is to sit and wait to watch another vehicle going through and see how far up it comes. Your other key factors are how solid the bottom of the river is in terms of traction and also whether there are any rocks / logs etc that you can't see underneath the water.

Your key issues are going to be your air intake, you spark plugs / lead, electrics in general. The key one is your air intake because BMWs often have them quite low down. In respect of diff breather pipes, etc, if you were properly preparing the vehicle for doing this alot then it would make sense but given you are only planning wading in exceptional circumstances, I wouldn't bother. You just need to be mindful that your diffs may require an oil change at some stage after because water may have got in them. Its not an immediate issue that has to be immediately rectified but it would cause damage over time. Have fun