Driving Through Floods !

dak

I had to drive my new Grande Megane 1.5 diesel through 4 flash floods in Freshford in Kilkenny last week. I drove through in first gear with high revs and pumped brakes afterwards etc which I believe is the way to go. Thankfully I got through safely .

A friend suggested that diesel cars are better for going through floods . Is this true and do modern cars have better sealing around the engine.

Whats the deepest flood you should attempt to drive through in a standard sized car . I personnally avoid taking the risk is at all possible as I have seen several SUV's fly through creating a wave over the bonnet of cars going through from the opposite direction with no consideration for the other driver !

Del2005

dak wrote: »

I had to drive my new Grande Megane 1.5 diesel through 4 flash floods in Freshford in Kilkenny last week. I drove through in first gear with high revs and pumped brakes afterwards etc which I believe is the way to go. Thankfully I got through safely .

Yes

A friend suggested that diesel cars are better for going through floods . Is this true and do modern cars have better sealing around the engine.

Old diesels has less electrical wires then petrols so where generally more tolerant of water outside the engine. All modern engines are full of electronics which really don't like water. No car engines are sealed, there's too many breather holes

Whats the deepest flood you should attempt to drive through in a standard sized car . I personnally avoid taking the risk is at all possible as I have seen several SUV's fly through creating a wave over the bonnet of cars going through from the opposite direction with no consideration for the other driver !

You're safe to any level below the sump, but the only way to know for sure is to walk it first.

Axe Rake

Slow down as you approach a flooded area.

It's best if you can avoid it all together however try to drive through the shallowest part but watch out for debris that might be hidden in the water.

Simply engage first gear and keep the engine running just above idle speed.

Also note that in older cars, driving at high revs could prevent water being drawn into the exhaust. However in many newer cars the air intake is positioned below the front bumper so avoid high revs as this would cause water to get sucked up.

And as you mentioned when you get out of the water apply the brakes gently a few times after to ensure they are working normally.

cian1500ww

Try to go as slow as possible through the flood, the faster you go, the more water gets thrown up and around the engine.

Atlantic Dawn

Deepest I would ever attempt would be to the base of the body of the car. One spoon of water taken inside the engine air intake is enough to write off an engine.

Matt Simis

cian1500ww wrote: »

Try to go as slow as possible through the flood, the faster you go, the more water gets thrown up and around the engine.

There are some that have a strong opinion on that (not me as such) that you should go fast enough to make a bow wave in front of the car, basically upto the grille. Such a wave stops water getting into the engine bay as would happen when driving slow.

I dont think its realistic to avoid sump level water, I think aiming for water below the air intake is more resonable IMO..

bonzodog2

Atlantic Dawn wrote: »

Deepest I would ever attempt would be to the base of the body of the car. One spoon of water taken inside the engine air intake is enough to write off an engine.

Possibly more so with diesels, with their higher compression ratio.

If you don't know the road, and the hedges etc dont give a clue, walk it first. Some cars (was it a Renault Espace ??) had a stupidly low air intake.

Too much water can bend con-rods

chessman

its not so much the depth of the water,but if its over 18 inches it will probablly get into the exhaust pipe and then you are in trouble,

peasant

chessman wrote: »

its not so much the depth of the water,but if its over 18 inches it will probablly get into the exhaust pipe and then you are in trouble,

Water in the exhaust pipe (as long as your engine is running) causes no trouble whatsoever ...unless you're going diving, the pressure of the exhaust gases will always be higher than the water pressure and keep the water from flowing into the engine (which would be quite a ways uphill from the tailpipe anyway)

How deep a pool of water you can ford without doing damage to your car really depends on your car ...the height of the air intake most of all ...so know how high or low yours is.

But even without sucking water into the engine (thus killing it) you can do damage. All sorts of electric and electronic components (from your alternator to your ECU) while spray proof, do not like a dunking. Also gearboxes and clutches have breather holes and react negatively to water and silt being sucked/flooded in.

If you're unsure as to how high or low your critical components are, I wouldn't really go any deeper than the bottom of the car ...which isn't all that much really ...maybe 10-15 cm on the average car(?) ..hardly a "flood"

Thoie

In general I'd try to find another route, but if I'm forced to go through, I'll always aim for the crown of the road.

peasant

Is this an opportune moment to show (off) what my Syncro could do?

sure it is ...

bbam

I had a R19 diesel years ago and got caught in a flood on way home from a nights work...

I had to cross a narrow flooded bridge, I pushed on through and the "bow wave" as it was called was at the tip of the bonnet..

The scarey thing was that with the narrow bridge the wave was bouncing of the stone walls and back to the car at window level :eek:..

No real problems except the clutch was a bit juddery for a while, garage reckoned that some crap had got brought in and no long term damage was done..

dak

Some Great Syncro videos around! Thanks !

peasant wrote: »

Is this an opportune moment to show (off) what my Syncro could do?

sure it is ...

CiniO

No one mentioned so far, no to use brakes excesively before going into the flood.
Brake disc when really warm, if they got hit with cold water, can easily bend. This will cause a car shaking while braking afterwards, and discs will need to be changed.

Just the worst you can do is to drive fast, see the flood, brake strongly to slow down before the flood and go straight into it.
If you see the flood in the last moment, slow down strongly, but wait for a couple of minutes to cool down your brake discs, before entering the flood.

Anan1

Is that second Syncro driving or floating?

peasant

bit o' both I'd say

Top Dog

Probably better to stay to shallower water than this lunatic

https://www.youtube.com/watch?v=j7gZ28Msa8g

peasant

Top Dog wrote: »

Probably better to stay to shallower water than this lunatic

but even there water getting into the exhaust isn't a problem

shogunpower

don't go near any puddles in an e60 5series anyway. stupidly low air intake, must have been 20 in David Prentice BMW garage after the floods in NI in 2008.All with blown diesel engines.

tossy

peasant wrote: »

Is this an opportune moment to show (off) what my Syncro could do?

More like flow motion than Syncro i'll get my coat!

Top Dog

peasant wrote: »

but even there water getting into the exhaust isn't a problem

True - but the breathing for the driver might be a bit dodgy :eek: