What breaks......Floods and water in the engine

[ratboiler]

Hi I am living just up from a flooded road which at the moment is around 2 feet deep and closed to traffic, and there are still people willing to give it a go, some get through but a lot of BMW drivers are not, latest one to fall fowl was a 5 series, I happen to know the guy who has just been told by the garage that he faces a 19k bill for a new engine.
Having stripped a few engines in my time and knowing that water is not compressible what actually breaks in the engine? I would have thought the head gasket would have gone first?

[TallPaul]

Con rods usually bend.

[jagracer]

[samuelellis]

jagracer said:

it is scary to think of the force required to do that

[marting]

Con rod painful experience...

[Stelvio1]

Indeed hydraulicing is not good!

[thinfourth2]

I saw a boat engine once that snapped the crank when water got up the exhaust.

However it kept running

[Mastodon2]

19K for a new engine? What was he driving?

[iva cosworth]

Mastodon2 said:

19K for a new engine? What was he driving?

OP says 5 series......the one fitted with platinum pistons

[eldar]

Mastodon2 said:

19K for a new engine? What was he driving?

New engine, ecu, turbo(s), other odds & ends BMW rate labour + VAT. Kind of plausible.

[real4star]

jagracer said:

That's just a kink, an American acquaintances Discovery 2 can beat that after some wading

[Flying Phil]

Some years ago I drove our Alfa 156 through some water _ only as deep as the top of the sill but the engine stopped and I had to take the plugs out and spin it on the starter. Got it going again and all seemed well for two weeks....... then the engine went Bang! The air intake to the air filter is surprisingly (Expensively!!) low on a 156.

[J4CKO]

I think I know why its BMW's having the problems, I was told about King Canute as a kid thinking the water would respond to his commands, I think BMW drivers think the same, well I have heard peopel call them Canutes, or something similar.

[BFG TERRANO]

9 out of 10 times a rod bends as already mentioned. Sometimes the crank may snap.

If It's really lucky and low speed you may be remove plugs, spin it over and pump out water and it will run again. Water won't compress very much so as the piston rises something has to give if It's full of water.

[omniflow]

J4CKO said:

I think I know why its BMW's having the problems, I was told about King Canute as a kid thinking the water would respond to his commands, I think BMW drivers think the same, well I have heard peopel call them Canutes, or something similar.

Google the Canute story, you've got it all wrong.

He didn't think the water would respond to his commands. The point was he was demonstrating the exact opposite.

[4key]

jagracer said:

That'll lower the compression a bit, just throw more boost and fuel in to compensate

[JDMDrifter]

Only issue I've had on my car is water drowns the carb , if you can keep the engine running at 2k rpm for about 10-15 mins it dries out and is fine

[Vipers]

Why be a dick and drive through water?

[MoelyCrio]

I'm not an engineer, so forgive the ignorance, but why don't the piston rings (or something else?) give up before the water compression bends the solid thing?

[LeeMad]

MoelyCrio said:

I'm not an engineer, so forgive the ignorance, but why don't the piston rings (or something else?) give up before the water compression bends the solid thing?

it happens pretty quickly, too quickly for the water to be squeezed through a small gap like between the rings. dont forget the force the crank is being turned with is enough to move 1-2 tonnes of metal