engine flush

The intended purpose of engine flushing oil (if that's what you're referring to) is supposedly to remove gunge before refilling with the correct grade of oil. In my opinion, a complete waste of time & money. Modern oils contain detergents anyway. Just drain your oil when hot and refill.

Terry D.

In message , Matthew H Williams writes

The purpose of a flushing agent is to "clean" any sludge or deposits from an engine prior to refilling it with new oil.

A couple of points to note though:-

1. You run the risk of dislodging a bit of muck which was not doing any harm and transporting it to another part of the engine where it might block an oil way and damage the engine.

1. If you use good quality oils in a modern engine and change that oil at the recommended intervals, your engine won't get sludgy. This was a phenomena of oils produced in the 80's and was often known as "black death". You don't often see this these days. I personally think engine flush is a waste of money.

Read more about black death, flushing oils and oil in general here:-