Engine flushing after oil draining - good/bad?

[uumode]

The guy who used to service my cars said engine flushing solutions (referring to my COMMA brand) said it was bad to flush the engine.

Another place recommends that the engine is flushed with
http://www.forteuk.co.uk/Advanced_formula.htm
after an oil drain and before the new oil is put in

Good or bad idea?

 

[glojo]

Brilliant question and I am posting merely to see any answers you might get. (If my e-mail notification gets fixed )

As a lay person, I would have thought flushing must surely be a good thing.

Fancy getting into a bath if the previous occupant hadn't cleaned it!! Yuk

Good luck with getting an informative reply.
John

 

[R2D2]

I was told it was good to do it sometimes to get rid of the rubbish floating about. I had mine flushed with a Wynn's product at 46,750 Miles and it did remove loads of c**p. I've not done it since though.

 

[jimmy]

It's good unless you have a real dirty engine and it is not flushed properly. The engine flush will then remove and loosen 'some' but not all the crud. This crud can then go onto block the oilways in very extreme cases.

If you are unsure of the history of the engine or the quality of oil used then use a flushing agent but run the engine for some time or even drive with it in for 20 miles or so then dump the oil, fit new filter and oil then do it again in a 1000 miles or so.

 

[jimmy]

Oh, by the way the Comma stuff is as good as they come.

 

[uumode]

I think the original guy advised it wasn't a good idea to flush, because the flushing solution itself has to be flushed out before the fresh oil is put in. So you would need to fill the engine with oil and then drain it again before the 'final' oil was put in.

 

[bangerman]

on high mileage cars not a good idea, remember the engine has worn and oil residue lies in micro pores in the cylinder bores etc
Using flushing oil removes this residue and can leave you with enough room for oil to seep past the Piston rings or higher up the problem is oil seeping through the valve guides. This would result in slightly smokey engine at high rev's or on engine rev come down.

But what do you class as a high mileage Mercedes? ( 100k or 200k ??)

 

[jgevers]

Hi,

In my garage we do not use flushing agents unless the engine is contaminated due to head gasket failure, black sludge etc.

The reason for not using a flushing agent is that when the oil/flush mix is drained, not all comes out. Most engines seem to hold on to about half a liter at least. This means that when the engine is re-filled with fresh oil, there is still flush left in.

On top of that, modern oils have plenty of detergents in to keep engines clean.

If you do want to use a flush, why spend money on expensive brands? As far as I know it is more or less straight diesel fuel re-packaged.

regards,

Job

 

[uumode]

Hi,

In my garage we do not use flushing agents unless the engine is contaminated due to head gasket failure, black sludge etc.

The reason for not using a flushing agent is that when the oil/flush mix is drained, not all comes out. Most engines seem to hold on to about half a liter at least. This means that when the engine is re-filled with fresh oil, there is still flush left in.

On top of that, modern oils have plenty of detergents in to keep engines clean.


regards,

Job

Thanks for your clarification, your argument seems to match my first servicing guys reasoning.

 

[mark.t]

flush

anyone any thoughts on flushing diesel engines,personally I'm not sure as I think the oil blackens as it hold the crud in suspension so when the old oil is dropped it should be like some sort of flush as it takes the crud with it, or would a flush be a good thing undecided on this one ..any thoughts

 

[Will]

How about a flush followed by two quick oil changes?

Ie, add flushing additive to old oil, drain and refill with fresh oil/filter, then change oil/filter in another couple of hundred miles?

Did that on one car in the past and the oil was nice and clean after a couple of thousand miles still.

Will

 

[jimmy]

..... use a flushing agent but run the engine for some time or even drive with it in for 20 miles or so then dump the oil, fit new filter and oil then do it again in a 1000 miles or so.

 

[Will]

Great minds think alike I suppose! :bannana:

Teach me to read the thread thoroughly again, I do remember your post now re: driving with the flushing oil in etc

Oh well, works for me too

Will

 

[fwb44]

Great minds think alike I suppose! :bannana:

Teach me to read the thread thoroughly again, I do remember your post now re: driving with the flushing oil in etc

Oh well, works for me too

Will

My garage has flushed the engine @ every oil change these last 3 years (180K miles = 11 services) and the engine sounds as good as new, never uses any oil, hardly any smoke except under hard acceleration - but I know these statistics aren't typical

 

[grober]

frequent changes

Comes down to the previous history of the car again!! I have read several posts in the past about this topic and the majority favour frequent oil and filter changes over "flushing" In other words you are using your new oil as a "flush" rather than the extra cost and labour of a flushing oil. How this plays out on a car with no oil change history is difficult to say. Maybe a rigorous flushing regime will clean up a poorly maintained engine difficult to say for sure. I have heard of people running the higher detergent diesel version of their normal oil for 3-4k miles to clean up their engine with no ill effects but difficult to measure the results other than the colour of the oil !!! The whole subject's a bit of a minefield. I personally favour the frequent oil/filter changes option myself.

 

[glojo]

I personally favour the frequent oil/filter changes option myself.

That would get my vote, although a high mileage vehicle with an unknown service history might well be a different decision.

John