[Travel] Flooded petrol engine - what’s the damage?

[Algernon]

The 4 phases of the 4 stroke cycle are:
Suck
Squeeze
Bang
Blow

If water has been drawn into the engine in the Suck phase then the squeeze will be what has caused the damage and an unwanted kind of Bang will occur.

Air can be compressed, and heats up in the Squeeze phase.
Water can't and so the pressure blows holes in bits and pieces in an engine. This is expensive to fix.

However if no water was drawn in she may have just covered electrical parts in water and they could possibly be replaced or even just dried out. This is also expensive if parts are needed but it depends on what parts.

Did water get inside the cabin of the car? Because some cars have their ECU (electronic brain) in the passenger footwell, behind the glovebox ish. It depends which car though, some are in the engine compartment. I don't know where it would be in a Mercedes but an ECU can be very expensive although there are companies that can swap a knackered one for one of their reconditioned ones. But some require a dealer to get involved in expensive computery jiggery pokery.

Get a report on the damage first then go from there of course.

 

[Fungus]

The 4 phases of the 4 stroke cycle are:
Suck
Squeeze
Bang
Blow

If water has been drawn into the engine in the Suck phase then the squeeze will be what has caused the damage and an unwanted kind of Bang will occur.

Air can be compressed, and heats up in the Squeeze phase.
Water can't and so the pressure blows holes in bits and pieces in an engine. This is expensive to fix.

However if no water was drawn in she may have just covered electrical parts in water and they could possibly be replaced or even just dried out. This is also expensive if parts are needed but it depends on what parts.

Did water get inside the cabin of the car? Because some cars have their ECU (electronic brain) in the passenger footwell, behind the glovebox ish. It depends which car though, some are in the engine compartment. I don't know where it would be in a Mercedes but an ECU can be very expensive although there are companies that can swap a knackered one for one of their reconditioned ones. But some require a dealer to get involved in expensive computery jiggery pokery.

Get a report on the damage first then go from there of course.

Thanks for the explanation; much as I expected. Her son is in the business, currently doing service and MOT on her husband’s identical Mercedes, but that’s up in Bognor. I’m sure he’ll get a full diagnosis, but I was curious about the likely outcome.

 

[Papak]

Depends on whether it is hydro locked or just some electrical components have been damaged by the water.

Is it a diesel or petrol engine?

Diesel engines are higher compression and much more likely to be destroyed by water in the cylinders, that said, a petrol engine won't fair much better tbh...

The fact it was driven for a few miles after the incident is potentially a good sign.

Hydrolock - Wikipedia

en.wikipedia.org

 

[zefarelly]

An impossible question to answer.

full water ingress could have hydraulic-ed inside and bent/damaged all sorts . . . . Or just got everything wet.

also depends on engine type and spec. . .

 

[Westdene Seagull]

The 4 phases
Suck
Squeeze
Bang
Blow

So many connotations !

 

[happypig]

Nothing wrong with driving in a bit of water:

 

[Fungus]

Will let you all know when I get an update. Thanks for the info.

 

[Lady Whistledown]

The 4 phases of the 4 stroke cycle are:
Suck
Squeeze
Bang
Blow

We can be but moments from @El Presidente making an appearance on this thread.

 

[AK74]

Can someone explain it better?

 

[ROSM]

We can be but moments from @El Presidente making an appearance on this thread.

A quick reference to 2 stroke should help summon him

 

[ROSM]

So many connotations !

That was how my physics o level teacher taught us about the 4 stroke internal combustion engine

It was certainly memorable to 15/16 year old boys

 

[OzMike]

She can afford a Merc, bin it and get another one.

 

[Justice]

My Escort Mk11 was a doodle to fix plenty of working space within the engine mounting. Shame it wouldn’t start in damp weather, I had to give the spark plugs a clean to get the old girl firing.

 

[RandyWanger]

My Escort Mk11 was a doodle to fix plenty of working space within the engine mounting. Shame it wouldn’t start in damp weather, I had to give the spark plugs a clean to get the old girl firing.

42 seconds it takes to swap out a Mk1 engine

 

[el punal]

The 4 phases of the 4 stroke cycle are:
Suck
Squeeze
Bang
Blow

If water has been drawn into the engine in the Suck phase then the squeeze will be what has caused the damage and an unwanted kind of Bang will occur.

Air can be compressed, and heats up in the Squeeze phase.
Water can't and so the pressure blows holes in bits and pieces in an engine. This is expensive to fix.

However if no water was drawn in she may have just covered electrical parts in water and they could possibly be replaced or even just dried out. This is also expensive if parts are needed but it depends on what parts.

Did water get inside the cabin of the car? Because some cars have their ECU (electronic brain) in the passenger footwell, behind the glovebox ish. It depends which car though, some are in the engine compartment. I don't know where it would be in a Mercedes but an ECU can be very expensive although there are companies that can swap a knackered one for one of their reconditioned ones. But some require a dealer to get involved in expensive computery jiggery pokery.

Get a report on the damage first then go from there of course.

“Suck, Squeeze, Bang, Blow” - thank goodness you were referring to the internal combustion engine. I happen to know a lady who does the aforementioned and knows nothing about cars.