Engine flush. Should I or should I not?

Mark rx450h · October 15, 2023

That is my question. In all my years of doing my own oil changes I've never used an engine oil flush.

I am wondering weather I need to or not to when you see how bad some toyota engines suffer from a tar like substance. I don't know what oil was used in the last couple of services so I have bought toyotas 0w20 as recommended, any info on oil flush and if there's a brand that works better than others.

Thanks in advance.

Spock66 · October 15, 2023

I would say not, but draining the oil when hot is definitely beneficial.

Malc1 · October 15, 2023

Oil flushes …….. is this really necessary or even desirable in modern engines having been properly serviced ?

an Urban Myth maybe, like UCL upper cylinder lubricant “ shots” with petrol refuelling in olden times !

My engine on 247k miles has never, to my knowledge, had other than simple ordinary oil and filter changes and ( touch wood ) functions well

I’m sure you’ll make the right decision for you …… just don’t waste your money if it’s an irrelevance

Best wishes

Malc

cdmaskell · October 15, 2023

As above do not waste your money. Complete con, as are the “Magic Pellets” in your fuel tank. Engine life has changed since 20/50 oil,and STP additives and non breathing engines.

J Henderson · October 15, 2023

Apparently an oil flush was performed at my last service. I didn't ask for it, but noticed the additional £5 charge on the invoice.

I didn't question it. The mechanics in the garage I use are a couple of older guys, very trustworthy with good Lexus knowledge. So, If anything, I was quite pleased to see it had been done since it was probably beneficial and the cost was next-to-nothing.

I believe a flush can clean out any deposits on the VVT solenoids, help cure cold-start rattle, rough idling etc.

My engine was not rattling and running fine beforehand, and still is, so no harm done.

Greisingel · October 16, 2023

Useful reminder. Haven't changed my oil since Feb 2021 and 8K miles.

I used to flush and run my 2001 E39 540i. Then one year I didn't and really i didn't notice any difference. It seemed to be all down to good draining and correct fill quantity.

Perhaps a quality Moly valve clean additive (I prefer Moly range...bit pricier) can do the cleaning job with the oil you put in thus avoiding the drain and fill twice pita.

But generally speaking a well drained engine and new, quality oil (I use Castrol Magnatec stop/start) seems to give me a lovely new engine tone when running.

oh yes, also buy a quality oil filter. Break open your old one and inspect for filings and unusual gunk gathering. Check via oil filler area for varnishing (use a little camera scope).

And never cane the poor bugger until up to engine temperature

GMB · October 16, 2023

My two pennyworth. It won't do any harm and would be a good idea if the car only does lots of low speed short journeys or has stood for a while. Carbon build up, condensation etc.☺️

12 minutes ago, Greisingel said:

And never cane the poor bugger until up to engine temperature

How true. The number of neighbours that like to blast off in their cold cars. Plonkers. Some would say that modern oil and engines do not reed molycoddling and don't even suggest careful running in. Do not believe them. I know differently from experience.

Look after your car and it will reward you with low maintenance costs.😇

Barry14UK · October 16, 2023

Of course engines as they age and the miles are piled on can suffer from carbon and burnt oil build up and even with modern oils. So a good flush now and again can be beneficial. However there isa risk of blocking an oilway with unfortunate results.

II had a Camry 2.5 v 6 some years where a head gasket failed resulting in overheating. A knock on effect was for hardened oil,carbob deposits peeled away and blocked the mesh on the oil strainer. Had the engine not overheated I am sure this would not have been a problem. It was not like the sludge found with old type oils. In my case the engine was flushed at least twice. but I wouldn't do it in normal use,

Mark rx450h · October 17, 2023

Thank you everyone. The car is only ever driven gently from cold. We have a lot of hills around here so you do have to come out of the green a lot and it's turned cold my mpg has dropped to around 37mpg uk imperial gallons.