Comma engine flush - yay/nay

Stonedofmoo · 21 Mar 2007 at 15:02

Now normally on engine flush posts I would advise not doing it as things can go wrong...

...however i'm about to service an engine that has 97,000 miles on it and the oil has not been changed for about 25-30k of those :eek:

What's left of the oil (and there isn't much) is something like molasses

So under such circumstances should I risk some comma oil flush and get the engine cleaned out?

I'm somewhat afraid it might leak from the seams afterwards

Liverpool-Lad · 21 Mar 2007 at 15:14

Either that or fill it with very cheap supermarket oil, take it out for a hard drive and drain and refill with good stuff?

Homeslice · 21 Mar 2007 at 15:15

Liverpool-Lad said:
Either that or fill it with very cheap supermarket oil, take it out for a hard drive and drain and refill with good stuff?

Sone · 21 Mar 2007 at 15:32

mickeyd did a good guide about this, recommened cheap oil mixed with atf

Simon · 21 Mar 2007 at 15:33

Liverpool-Lad said:
Either that or fill it with very cheap supermarket oil, take it out for a hard drive and drain and refill with good stuff?

Much better idea although there is no need to take it for a hard drive, infact I would advise against it on a cheap oil. Just get it up to temp and drive it for a fairly long trip.

Avalon · 21 Mar 2007 at 15:36

Remember it'll need two filters, the cheap flush will hopefully break down most of the crap gunk in it but it'll block the filter up something shocking. Having been in the same position I used very high grade diesel engine oil (in a petrol engine) as it contains a shed load more detergant (this was after asking both mechanics in the family as I though they were kidding), warmed it up gently and gave it a good run, the crap that came out with the oil was pretty bad and I was concerned i'd loose compression after but it seems to be fine now with another 20k on the clock. YMMV ... litrally!

Stonedofmoo · 21 Mar 2007 at 16:08

The comma stuff is not an additive to exisiting oil like some and its sold down my local motorfactors

They basically say put in 2.5 litres, and fast idle the engine for 10mins and empty and replace with fresh oil

This stuff here: http://www.commaoil.com/Product Pages/Oilsnlubes/flushout.htm

Simon · 21 Mar 2007 at 16:42

Stonedofmoo said:
The comma stuff is not an additive to exisiting oil like some and its sold down my local motorfactors

They basically say put in 2.5 litres, and fast idle the engine for 10mins and empty and replace with fresh oil

This stuff here: http://www.commaoil.com/Product Pages/Oilsnlubes/flushout.htm

2.5 litres isnt enough oil for most engines

Simon · 21 Mar 2007 at 16:45

Avalon said:
Remember it'll need two filters, the cheap flush will hopefully break down most of the crap gunk in it but it'll block the filter up something shocking. Having been in the same position I used very high grade diesel engine oil (in a petrol engine) as it contains a shed load more detergant !

Diesel engine oil simply contains more dispersants due to the nature of diesel combustion and it's soot loading of the oil. These dispersants stop the soot clumping up and forming deposits. This is why oil in diesel engine goes black so quickly, it's holding the soot within the oil and is why dirty oil is a good thing.

Stonedofmoo · 21 Mar 2007 at 17:03

Simon said:
2.5 litres isnt enough oil for most engines

Thats what I thought, but it clearly says half the normal amount of oil is sufficient. So in the Vectra's case 2.5 litres would be more than they actually recommend

Matt82 · 21 Mar 2007 at 19:00

before youre due a change, add about 0,5 L of autogearbox fluid with the oil, run it for a week or so, 200-300 miles should be ok.

amazning at cleaning stuff because it is so full of detergents etc

Simon · 21 Mar 2007 at 19:08

Stonedofmoo said:
Thats what I thought, but it clearly says half the normal amount of oil is sufficient. So in the Vectra's case 2.5 litres would be more than they actually recommend

I'd never run an engine with that amount of oil.

Stonedofmoo · 21 Mar 2007 at 19:09

I don't think i'll risk it either

...although ironically thats probably more oil than she had in there last saturday!!

silversurfer · 21 Mar 2007 at 19:13

I remember AGW saying he did this with some diesel oil.
If it were me, I'd probably just get the oil and filter changed and then do it 1000 miles after again but if it blocks the filter straight away you think, that'd be bad

Is this the Saab we're talking about?

I remember on some car vid, they cut open the filter after changing oil to try and gauge any problems.

Ive run engines with barely the end of the dipstick showing a mark, you could actually hear more engine noise on starting

I think the top of the engine struggles with lubrication in that case and any g force is not good

Stonedofmoo · 21 Mar 2007 at 19:18

God no, I maintain my cars religiously!!

This is the gf's Vauxhall Vectra GLS

Dogbreath · 21 Mar 2007 at 22:37

The more crud that has built up in an engine, the more harm "flushing oils" can potentialy do by blocking oilways etc.

Stonedofmoo · 22 Mar 2007 at 08:03

Right well thanks for the replies. I've had some more correspondence with Lisa at Comma oils and she basically said this on the oil flush I have

It will clean it a little but it is just a basic oil with a basic additive. It may be worth using this to begin with and clear out most of the muck and when the engine has got use to the new clean oil you can use the other product when the next oil change is due just to give it an extra cleaning boost.

Which sounds perfect for my needs. I really don't wish to make it shiny clean inside, just simply remove the old oil gunk.

:cool:

Matt82 · 22 Mar 2007 at 21:22

not the clearest picture ever, but this is the inside of my golf's head.

http://www.picturevillage.com/photo/showpic.php?uuid=3557&aid=24049&pid=339452

has done 158k+ miles, no built up crud anywhere to be seen. done the auto gearbox fluid trick a couple times. when the oil has drained away, its all a lightly tinted silver colour

Jonny69 · 22 Mar 2007 at 22:33

Cheap oil, 500 miles, change it again.

agw_01 · 22 Mar 2007 at 22:37

silversurfer said:
I remember AGW saying he did this with some diesel oil.
If it were me, I'd probably just get the oil and filter changed and then do it 1000 miles after again but if it blocks the filter straight away you think, that'd be bad

Yeah, apparently it's good to do it with an engine that you don't know the history of. The extra detergents in diesel oil help get rid of years of gunk.

There was a guy on Rovertech who took the sump off an engine before and after running it with diesel oil. If the photos were true, it was very impressive.

Comma engine flush - yay/nay

Man of Honour