Straw poll on engine flushes

[m4rkw]

When you last changed your oil, was there an 'engine flush' item listed on the invoice?

This is apparently quite common these days, my local garage has been doing it, but from what I've learned a flush is at least unnecessary and in some cases can even harm the engine.

I think next time it goes in I'm going to ask them not to flush it.

[C Mclean]

Personally I wouldn’t bother with it, sounds like the USA model where drivers are persuaded to get get the engine flush, tyres rotated, AC cleaned and disinfected, plus anything else they can think of to bump up the cost.

[m4rkw]

Well in the case of my garage, who I do otherwise trust, it was done without any prior approval. However next time I think I'm going to ask them not to. They used a flush when changing the coolant as well.

[C Mclean]

Mmm, I think I’d be checking what the service book says and comparing it to what the dealer done. 

[m4rkw]

The service book definitely doesn't recommend flushes.

[Guest]

There are pros and cons

If your engine get's very dirty and sludges rings etc then a good flush will help (as long as a top quality reputable product) - we are talking dirty diesel here really.

With regards petrol engines run on top quality oil and changed on time it's a risk you don't need to take. 

It's a risk because unless you know the flush chosen and the oil chosen don't react chemically...... should you mix them?

Liqui Molly state their product doesn't react "If applied correctly" . What does that mean? What if it's not done correctly?

Lastly - there are no standards for additives. IE a company can make and sell whatever they like and call it an oil additive. 

[Herbie]

What he said^^^^^^^^^^^^

[Fsport]

Avoid a flush.  If you want to clean your engine it is better to just change the oil again within a few miles eg 50 miles.  Alot more safer than a dedicated flush.

[Dewillia]

I think the oil in most modern cars is sucked out anyway