Negociating Floods

Kalashnikov_Kid

Ive only 5 months driving experience on a 99 1.4 Polo and nearly got cought out tonight near Dundalk.
This will give you a good idea of what im on about!
http://www.meteireann.com/latest/rainfall_radar.asp


You know the story... the road ahead is flooded on both sides but theres no garda presence and no-one there to assist you and you decide to chance it...


whats the best driving technique to get you through without screwing up your engine?

Cheers,

KK

Bam Bam

Get out of the car and try to see how deep it is IE use a stone ar a stick.

If you're not sure don't chance it.

hellboy99

best thing to do is to reverse and find another route if you can. if thats not possible and you think it's not too deep then put the car into second and drive through it steady, don't let your foot off the accelerator or you'll end up sucking water up in the exhaust and the engine will cut out. don't ever go through water if there's a car driving in it, always let them go and allow the water to settle.

Kalashnikov_Kid

hellboy99 wrote:

best thing to do is to reverse and find another route if you can. if thats not possible and you think it's not too deep then put the car into second and drive through it steady, don't let your foot off the accelerator or you'll end up sucking water up in the exhaust and the engine will cut out. don't ever go through water if there's a car driving in it, always let them go and allow the water to settle.

I tried 2 routes already and most people were turning away (live out in Blackrock you might know what the flooding is like there)

I put it to first it went smoothly until at its deepest point when the water went over the bumpers, engine started revving very high and started chugging on the final 10 yards, but kept it in first and got through...scary stuff!

hellboy99

Kalashnikov_Kid wrote:

I tried 2 routes already and most people were turning away (live out in Blackrock you might know what the flooding is like there)

I know it well, least you got through it. Watch yourself tomorrow as it's suppose to be rain all day.

seamus

If you know the road well, or it's a narrower, older road, you're better off testing out the dead center of the road. Using a stick, you should be able to tell which way the camber on the road is (afaik, it usually slopes from centre to edge). Your main aim is to keep the engine as far out of the water as possible.

Rovi

As others have said: if in doubt, turn around and find another route.

Most SUVs will have a 'safe wading depth' specified in their owner's manual, but I don't think many cars will have this.
Find out where your car's air intake is. If you submerge this, you'll suck water into the filter/engine and stall in the middle of the flood at best; at worst, you'll destroy the engine. Most car air intakes are somewhere behind the front grill, but some are down pretty low in/near the bumper.
Be aware too, that belts/pulleys/fans will fling water up into the engine compartment which could drown the ignition or fuel systems even if the water isn't deep enough to reach them if the engine wasn't running.
If you get in so deep that the fan gets a grip in the water, it could possibly pull itself into the radiator and do terminal damage to it.

Your 'safe wading depth' will be a bit below the lowest of these things.

Check the depth of the water. This may even involve a bit of wading (take off your shoes and socks first ), but better that than getting the car in too deep with no hope of retreat. Be especially watchful for 'surprises': potholes or other deep spots that will suddenly drop the car into deeper water.
I'd be of the opinion that anything much over six inches deep is getting marginal for driving a conventional car through.

If you're satisfied that the water is negotiable, proceed slowly but with a little determination. Don't slow down, hesitate, or stop in the middle.
You're looking to go fast enough to make it through and not let water back up the exhaust pipe, but not so fast that you splash water up into the engine compartment.
First gear with maybe two thousand revs or so should be fine. If the water is so deep that this won't get you through, I'd strongly suggest not attempting it in the first place.
Don't worry about stuff like bow-waves and negative pressure in the engine compartment and all that stuff, these are pretty advanced off-roading techniques that are well beyond what we're talking about here.
Ideally, you should turn off your headlights and allow them to cool as immersion in cold water could crack hot lenses,but if you're in over the headlights, I think that a cracked lens is the least of your troubles.

When you're through the flood, apply the brakes gently a few times as you slowly drive along to dry them out.

Have the car serviced as soon as possible afterwards; water in the gearbox/engine sump, suspension joints, CV boots, alternator, etc, will rapidly destroy these parts.

Pigeon Reaper

I'm in a water rescue unit. Unless you have experience or training in driving through floods turn around and try another route. If the water is flowing it only takes a few CMs before the car is swept away. If it is a fast flowing flood the road may be gone or impassable due to something below the water. Personally I don't drive through floods in my car, it's not worth risking your car or worse. In the past this has meant waiting for a number of hours for the water to clear.

Sam Vimes

well don't do what i saw before. the road was flooded for about 30 feet but the paths on both sides weren't. someone in a 4x4 tried to get up on the path but got stuck in the grass verge. then ten other people said "my micra is far better than that 4x4, i'll try to make it over the verge". they should each get a darwin award