Engine Flush Is it needed? Does it work?

[Nodzed]

Just though I'd share this,
Over the years I have always shied away from using flushes, mainly from horror stories of high mileage engines in the 80s being wrecked by using them and running out the shells, I have no evidence this was true just hearsay and articles in motoring magazines etc (pre-internet days) but I've done an oil / filter change today on my Zed ready for the up and coming Euro run and decided after speaking to a few people on here that has used them, and the fact I had a sticky lifter on cold start up I decided to try one.

The oil had only been in the engine for just over 5k and though slightly dis-coloured before adding the flush, once added to the up to temp engine and run for 10 minutes on tick over and drained the oil that came out was black! Now being a bit of a sceptic I though the additive had done this to show something had happened, but removal of the filter showed that something had happen. The caramel discoloring that is always coating the inside of the housing (and is always covering everything else inside the engine, and that I normally wipe off) wasn't there in fact the inside of the housing was completely clean. So I am assuming its done a similar job else where.

I am a little surprised to be honest
So I am now of the opinion they do clean off the residues, but still not so sure you need to. I'll report if its cured the sticky lifter later on.

 

[Nodzed]

Reserved

 

[Paul Rice]

Over the last four years at annual oil change had the engine flushed. Car fast approaching 100k still runs as sweet as a nut 40mpg+ and although not up to the bigger engined models has a good turn of speed. For what is a minimum cost works for me.

 

[Pingu]

I would steer clear of it on a well maintained engine as it does what you say - it chemically strips the inside of the engine. This means that when you put the new oil in, there will be a short period when there is no lubrication. As most people know, most engine wear happens in the first few seconds after start-up - this is when you need the lubrication that the flush has removed.

On a poorly maintained or old engine, the flush removes the excessive gunk that is inside the engine and helps to clear the oil-ways.

I use it on my van, as it's an old knacker that has had 265,000 miles of hard life and gets cheap oil (£40 for 20 litres). My toys are well maintained with high quality oil (£30 for 5 litres).

 

[t-tony]

There are mainly two types of engine flush, those that have lubricating properties and those that don't. Always follow the directions on the container closely.
I use Forte, because it has very good lubrication properties and you can run this in the engine for a couple of days before changing the oil.

Tony.

 

[gookah]

I use it with all my oil changes now after a few sticky lifters were immediately cured by it and have never returned..

 

[Lee]

I use it with all my oil changes now after a few sticky lifters were immediately cured by it and have never returned..

Exactly what I was going to say, cured my N52. Run a flush every other oil change.

 

[Bozzy]

I've used an engine flush before oil changes for the past few years,no issues yet.
Sara's Vauxhall has nearly 100k miles on it,when we bought it,it had 15k miles on it.
Always used a flushing agent on it and never had any troubles........so far.

Steve

 

[t-tony]

Exactly why I started using a flush too. My Z3 2.0 had a rattley tappet and after using Forte flush it was gone. Roy @Rha always used to comment how quiet my Z3 ran.

Tony.

 

[Nodzed]

There are mainly two types of engine flush, those that have lubricating properties and those that don't. Always follow the directions on the container closely.
I use Forte, because it has very good lubrication properties and you can run this in the engine for a couple of days before changing the oil.

Tony.

Hi mate, glad thats a good one thats the one I used.

 

[Nodzed]

Exactly what I was going to say, cured my N52. Run a flush every other oil change.

Hi I used it following our discussion mate ... the trust I put in you!!

 

[t-tony]

Just though I'd share this,
Over the years I have always shied away from using flushes, mainly from horror stories of high mileage engines in the 80s being wrecked by using them and running out the shells, I have no evidence this was true just hearsay and articles in motoring magazines etc (pre-internet days) but I've done an oil / filter change today on my Zed ready for the up and coming Euro run and decided after speaking to a few people on here that has used them, and the fact I had a sticky lifter on cold start up I decided to try one.

The oil had only been in the engine for just over 5k and though slightly dis-coloured before adding the flush, once added to the up to temp engine and run for 10 minutes on tick over and drained the oil that came out was black! Now being a bit of a sceptic I though the additive had done this to show something had happened, but removal of the filter showed that something had happen. The caramel discoloring that is always coating the inside of the housing (and is always covering everything else inside the engine, and that I normally wipe off) wasn't there in fact the inside of the housing was completely clean. So I am assuming its done a similar job else where.

I am a little surprised to be honest
So I am now of the opinion they do clean off the residues, but still not so sure you need to. I'll report if its cured the sticky lifter later on.

I used a flush in my Z3 for just this problem, and I also added some Wynn's Hydraulic Valve Lifter concentrate with the new oil too. We've used this additive at work for many years, it is a great product.

Tony.

 

[Rha]

Exactly why I started using a flush too. My Z3 2.0 had a rattley tappet and after using Forte flush it was gone. Roy @Rha always used to comment how quiet my Z3 ran.

Tony.

Ha ha, yes (still do with his Z4 30) and when parked next to Tony's Z3 it made mine sound like a diesel so if you've got a noisy engine it will eather quieten it down or it's needing some more in depth maintenance like mine, which probably needs Mr Vanos.

RHA, Roy.

 

[handsomejackuk]

1

 

[hard top]

1

??

 

[GuidoK]

I always use some diesel as engine flush.
Right before the oil change, I tap off 1L of oil, add 1L of diesel and let it idle for about 30min.
Then do the oil change.

 

[Lee]

I always use some diesel as engine flush.
Right before the oil change, I tap off 1L of oil, add 1L of diesel and let it idle for about 30min.
Then do the oil change.

Never heard of that before, is it effective?

 

[mwpe]

Interesting thread, I have always been wary of using flushes but I think I might try it, Too late for this year as I have just done the oil change, but one for next year.

 

[Jack Ratt]

I always use some diesel as engine flush.
Right before the oil change, I tap off 1L of oil, add 1L of diesel and let it idle for about 30min.
Then do the oil change.

I've done this too. It's the detergent in modern diesel fuels that make it effective

 

[GuidoK]

I've done this too. It's the detergent in modern diesel fuels that make it effective

Not only the detergents.
Diesel itself is a very light oil. Like penetrating oil.
Light oils are good at dissolving non polaric residues.

Because diesel is a light oil in itself I dont believe it's doing any harm to the engine when the engine is only idling, when used as a 1:5 mixture with the remaining oil.
I've seen video's on youtube where people completely remove the engine oil and flush with 100% diesel, but I cant imagine that leaving damage. Diesel doesnt provide the thick oil film that engine oil does.

This was my cylinder head after 80k miles, I think its pretty clean. This cover is taken off at a time that the oil change was also due, so what you see has been running in the same oil for about 10-15k miles and then flushed with 1L diesel):

No usual staining of the vanos yet.
Obviously that also has to do with climate, engine design etc.
But this engine leads a hard life as its tuned to 350+bhp (supercharged) and is often used as such (autobahn runs, alpine hoons etc).

I admit I'm not the first owner so I dont know how its previously been treated (from what I see on most aspects of the car pretty good though)

I also use diesel as a gunk cleaner for carparts and works pretty well (better than other oily products like wd40 etc). Its not as effective (aggressive) as gasoline etc. but putting gasoline into your engine oil is a really bad idea