"washing the bores"

[texaxile]

Nothing to do with chucking water over Giles Brandreth, but more about a phrase I've not heard in a while.

Going back a bit, pre injection , I'd like to ask the collective if there ever was such a thing, that being from my limited understanding that a vehicle running too rich would send too much fuel into the head and effectively reduce the lubrication of the oil in the cylinders, the excess fuel "washing" off the lubrication , unburnt fuel being exhausted and as a result, excess wear in the cylinder bores, usually indicated by brown smoke from the exhaust under load, such as driving the car under "choke" all the time. (Remember them?)

Secondly, and perhaps more relevant, with modern fuel injected engines, is this now a thing of the past, if it ever was a "thing"?.

[Skyedriver]

It is my understanding that starting a cold car to move it then switch off can cause this as the car is effectively running on "choke" . But I'm no expert.

[GreenV8S]

It definitely used to be a thing - unlikely to be an issue these days with modern engine management systems.

[AdamIndy]

Definitely can happen and i have seen it with my own eyes. I witnessed a 15k+ engine get borewashed and lunch itself within 50 miles. It was running on carbs though.

I would imagine with modern technology it could only happen through massive injector failure or piss poor mapping these days. It wouldn’t happen without warning though.

[Evoluzione]

Known as bore wash. Still readily available from your local cowboy tuner if needed.
In a standard untouched car? Highly unlikely.

[steveo3002]

would be result of a fault like a stuck injector , not by running a cold engine etc

[normalbloke]

Still very much a thing, especially with diesels and failed dpf regens. Just look at the VW 180bhp BiTdi as an example.

[Boosted LS1]

It certainly can happen if for any reason excess fuel enters the cylinder. Piston manufacturers warn against over enrichment when an engine's first run after a rebuild.