What's the maximum depth of water I can drive my P6 through?!?

[mrtask]

Here in Berlin the heavens have been pouring a quite unbelievable amount of rain down upon us sodden citizens, which has led to flash flooding when the storm drains can't cope with the deluge. Yesterday I drove through some standing water which sent huge cascades up in the air to either side, and I was a little bit afraid of possibly conking out! I was especially worried because I no longer have a mechanical fan, and the Kenlowe fan I fitted in front of my radiator has the wiring running alongside the power steering hoses at the base of the rad, at a height at which I think it was quite possibly submerged! Seems to all still be working, but I did worry a bit! I wonder if anybody can tell me, what is the maximum depth of water that can be driven through in a P6?

 

[colnerov]

Hi, You were possibly fortunate that you didn't have the mechanical fan on because that can pick up water and throw it all over the engine. This tends to suddenly cool things like the dist cap and create condensation inside, then it would conk out. There is a technique for driving through deep water which is to create a bow wave in front of the vehicle thus leaving the engine in the lower water behind it, you need to get the speed right and maintain it.

Colin

 

[Demetris]

I would say if you don't know how deep it is, just don't risk it. Also how you tackle it, is more important than the actual depth; within reasonable limits of course.
The speed is quite critical, slow enough to maintain control and visibility without splashing water within the engine bay for the reasons Colin mentioned above, but also fast enough to create and maintain that bow wave if the water is higher than the front valance. In the V8 the distributor is rather high, so your primary concern should be splashing water rather than actual depth. Also mind you that pushing quantities of water consumes power, so be prepared.
That's all the theory, but of course if you don't practice is not easy to know how it feels.
Last but not least, in my P6 i would avoid anything above wheel hub level. Water entering the wheel bearings, the sills, etc can be an expensive experience.

 

[Quagmire]

This is the kind of question i would expect to see on LR4x4! Never thought I would see it on here

Demetris has got it covered, but also bear in mind that if the clutch gets wet it will slip heavily. I did this once in my Landrover when I forgot to put the wading plug into the bellhousing, whoops!

 

[mrtask]

Excellent information chaps. It was hard to judge the height of the water from in the drivers seat, but I did worry that it might well've reached the height of the front bumper, and thus also the motor of the electric fan, and therefore very possibly the inner sills and the long rear suspension arms and elbows. The 'deep' water was only for about three car lengths, and in all likelihood didn't in fact come up as high as the wheel bearings, but I'll put the car up on my lift this weekend and take a good look around underneath, and very possibly whip off the outer sill covers for peace of mind. After the brief 'fording' episode the car conveyed my wife and I all the way across town and back in absolutely torrential rain without missing a beat, I'm delighted to attest. Using the fast wipe is always a bit disconcerting, I worry a wiper arm will be flung off!

 

[classicalgreen]

correct comments on bow wave for driving in deep water. however thats mainly for cars and truck designed to do so! e.g. land rovers . etc would not drive through anything over half hub cap height and even then worry about water ingress into cavities etc .unless waxoled etc .
apart from water getting flung about engine bay and causing cutting out in middle of a wading session. one needs be aware brakes will need couple of light applications after a drenching to dry off or one may find a sudden stomach churning moment with np apparent brakes on first heavy application.
personally not an issue as I never take mine out in rain. I wash it with waterless system so reducing any moisture/rust issues to absolute minimum. have even missed shows due to rain. aware cars are there to be used not sat in garages all day. however costs and time invested thus far make it far to expensive to suddenly get an attack of the dreaded rust bug. as outer panels are not structural we can easily gain a false sense of security etc. car structure itself especially inner sections need to be kept clean and dry for longevity as water and heat can soon creep in with subsequent costly damage and repairs . ideally find another way around so wading is avoided thus risks negated.

 

[Dave3066]

It's been pretty wet here the last week or so too. I remember flying back into Edinburgh airport after a meeting in London one evening to find the exit road from the airport was flooded. If I wanted to get home I had no option but to drive the P6 through the water. I was paying close attention to other vehicles as they drove through and judged that it would be okay for the P6. The water was easily up to the height of the top of the sills but I made it through by taking it easy and keeping the engine revs high enough to stop any water going up the exhaust. I had about an hour long drive home after that which probably helped dry things out, but there were no ill-effects as a result of driving through the water. As others have said, if you're not sure how deep it is either find out by other means or find another route. I had no choice that day.

Dave