In various magazines I have read that it not only bad practice to allow the car engine to idle whilst cleaning the windows from ice and snow, but it also does more damage than good. They suggest that you start the car and drive off immediately. Can anyone explain to me why this is so. I cannot see any reason why damage will be done to the engine when idling - let's face it when you are stuck in a traffic jam you can sit for ages with the engine ticking over with no bad results.

Never heard this before, probably the save the planet green brigade perpetuating the myth that it's causing global warming. I often do it in the wife's car. Mine's always garaged so never needed to.

your car handbook will say the same, it is not eco myth

basically it is increasing wear on the engine - google it for more information

Letting an engine tick over to warm up from cold is the worst thing you can possibly do, if done with a modern Diesel with DPF you will kill it in no time.

This is not a myth, and nothing to do with the green brigade, or EU.

I speak from over 40 years as a Motor Vehicle Technician.

Engine/gearbox warms up driving, not idling, so move on buddy.

A petrol might warm up gradually but a diesel being more fuel efficient probably won't. Cold running accelerates wear in an engine as all the parts are designed to move together properly at operating temperature. When they are not then the parts of the engine that are made from different metals will be at different sizes and so will bang together and cause more wear. Of course this is only in fractions of millimetre but it is enough to make a difference. That is why it is reckoned to be best to drive away straight away, not gunning the engine but relatively gently so everything warms up quicker.

Ian

I remember being told that when a petrol engine was started the fuel/air mixture was rich, so if it was left idling for a while just after it was started, the petrol rich mixture diluted/cleaned away the lubricating oil between the piston and cylinder wall and caused more wear than just starting and driving away. Dunno if it's still true or not.

Letting an engine tick over to warm up from cold is the worst thing you can possibly do, if done with a modern Diesel with DPF you will kill it in no time.

This is not a myth, and nothing to do with the green brigade, or EU.

I speak from over 40 years as a Motor Vehicle Technician.

your car handbook will say the same, it is not eco myth

basically it is increasing wear on the engine - google it for more information

I said that I hadn't heard it before, not that it was a myth that it was bad practice. The myth I flippantly referred to was about it [meaning the car in general] contributing to global warming.

I speak from over 15 years as a Doctor of Paleoclimatology [that's a joke, obviously ].

Edited 15 January, 201214 yr by Guest

The general idea is to get your oil up to temperature as soon as possible. This won't happen on idle, you need to drive the car.

There used to be a Castrol GTX advert that reckoned a high percentage of engine wear happens on cold starts as the oil is not distributed evenly, and it isn't up to temperature.

The general idea is to get your oil up to temperature as soon as possible. This won't happen on idle, you need to drive the car.

There used to be a Castrol GTX advert that reckoned a high percentage of engine wear happens on cold starts as the oil is not distributed evenly, and it isn't up to temperature.

IMHO - after engine started on cold, oil supposed to have a chance get distributed - which takes few seconds; i.e., ideally good idea to warm up about 30 sec before start driving; I even had such a rule in my previous Nissan petrol car manual. Nobody talking about minutes until engine get warm (particularly for disels). So the truth always somewhere between...

Well this morning was -5 here so i as usual scraped all the windows(amazing how many people dont)

clutch in started the car and slowly released the clutch.

Front and rear demister on, heated mirrors on, seatbelt on, lights on and drove away changing at below 2000rpm but without having the engine labour.