Engine flush - Good, Bad, Ugly?

[Robinxr4i]

I'm about to do my first oil change on the my E30 318, the engine has done approx 97,000 miles and I've got no history with it. Anyway..........

Right engine flush, I've used it several times in the past and the results seem to be inconclusive. I know it's meant to remove harmful stuff from the engine and I'm not expecting a performance increase or the engine to run noticeably better from just one treatment, but I seem to find when I use it the engine end up using more oil than before (or maybe I imagined this )

I was once told by an ex-ford technician that "in his opinion" if the engine had always had a flush every time the oil is changed then you'll increase the engines life, BUT if the engine has never had an engine flush say for arguments sake 100,000 miles, then you use engine flush you risk disturbing deposits that might not be removed when change the oil. Causing potential damage to the engine. Any true in this?

Just wondering if the consensus is on it? What are the fact (if there are any)? Should I flush the engine in my E30 before I change the oil?

Love and kisses Robin ;D

[waveman1500]

I would just put clean oil in, who knows what that engine flush stuff might do. All of your oil seals might be held together with the crusty deposits! If it runs nicely and doesn't leak or burn oil, then leave well enough alone, I say.

[will]

If it ain't broke don't fix it - my 2p

Recently flushed a swapped 4 stroke dirt bike with diesel after 2 people gave the same advice. The bike had gone down in a muddy pond and hydraulic locked the motor with feted swamp water, derv worked a treat with no noticeable ill effects. Still stand by first comment though

[lolface]

I heard horror stories too about engine flush, tbh I wouldn't bother either.
no oil gallery is made narrow enough to be blocked by oil sludge if it's had filter changes. Many peeps use it as a lazy way of silencing sticky hydraulic lifters, which the 318 engine doesn't have does it? (sorry not very clued up on these .
+it's made to be aggressive enough to dilute oil deposits so it can't be doing much good to seals methinks.

[ruishy1]

use a mix of 75% diesel and 25 % 90w gear oil and run it through your engine, keeping an eye on the water temp.
Keep doing this untill the oil you put in comes out nice and clean

[Deleted]

a lot of people say engine flush ruins engines this is complete rubbish all engine flush will do is show up a problem if the engine is already ruined sometimes the crud buildup in an engine can mask what is really wrong with it and once all that crud has been removed it will start to reveal the underlying problem . i have flushed through lots of engines with no problems . at least if it does show up a problem you will have a nice clean engine to rebuild

[bodieanddoyle]

Feb 18, 2010 7:46:16 GMT nightmaresracing said:

a lot of people say engine flush ruins engines this is complete rubbish all engine flush will do is show up a problem if the engine is already ruined

not BMWs- they seem to have an odd shell bearing material that likes to lunch itself when you put flushing oil in them. I would NOT use a flush in any BMW.

stick 4 litres of cheap oil in, run it for 250 miles then change it, that will get a lot of any sludgey deposits out without harming a thing. then make the next service at like 500-1000 miles and change again, that will have it looking nice and golden inside in no time.

[Lewis]

I'd never put something in that thins oil down, then proceed to run the engine for any period of time. Just doesn't even make any sense on that front!

Like bodie says, I'd rather run a few cheap oil changes through it (maybe with some diesel oil in it for the detergents) if I was that bothered about it.

[steveo3002]

ive had good results with atf ...use about 1 litre in the oil for a few hundred miles and change , repeat if its a minger

[Oldbus]

I´ve always used diesel to flush out my engines over the years - never had any problems.

Don´t drive the engine anywhere with diesel in it though - just let it idle until it´s all warmed up and then bin the sludge.

If you´re unsure just change the oil and filter after a week of driving it around.

[ChasR]

I agree with the if it ain't broke idea.

A very experienced engine builder told me that if you need to flush the engine through, change the oil at around the 1000 mile mark.

I did something similar to this in the Peugeot 306 and the oil is now quite clean again (well, as clean as it can be for a derv).

As said the flushes can start to make the engine leak around the seals which is not an underlying problem. Remember that our cars were built when 20W50 looked thin and radical.

[Deleted]

Well if the seals leak with flush in due the the flush being to thin then once the correct oil is put back in they should be fine if not they were already shot . I do agree though about just using fresh oil if you are in any doubt out the engine you want to clean

[misteralz]

On my Golf I'll drop a litre a few hundred miles before an oil change and then top it back up with ATF. Works a treat.

[mdh]

Feb 18, 2010 7:46:16 GMT nightmaresracing said:

a lot of people say engine flush ruins engines this is complete rubbish all engine flush will do is show up a problem if the engine is already ruined sometimes the crud buildup in an engine can mask what is really wrong with it and once all that crud has been removed it will start to reveal the underlying problem . I have flushed through lots of engines with no problems . at least if it does show up a problem you will have a nice clean engine to rebuild

It ruined 3 Rover V8's of mine.
This was the flushing stuff that you add to your oil.
All 3 developed major oil leaks afterwards.

Ive been told that old style flushing oil, where you replace yoor old oil with it run for 5 mins then drain, is better.

[DavidB]

I've used Winn's engine flush everytime I change the oil. I'm of the understanding that it thins the oil out enough to remove a small amount of crud, which is okay for me as I want my oil clean when I put it in. Not had any back things happen as a result though. The tappet that taps on start up has been the same every oil change as well.

[10mpg]

I once bought a late 90's fiesta 1.4 zetec S cheap cheap because it was kicking out heavy blue smoke, it'd just had a service and an engine flush I drained the oil put in fresh 10/40 and drove it for 10 miles, the smoke stopped after about 5 or 6 miles and it ran beautifully, passed it's MOT no problem with good emissions and thereafter used no oil at all...

Going from this I'd not use engine flush's unless the engine is severely choked up with crud as oil changes have been severely neglected, but then the engines probably bushed anyway so you don't stand to gain much!

I have used it to good effect on vintage engines that have been sitting in barns ect but the engine when laid up was known to be extremely good or freshly built but where over time the oil has turned to tar, but this i very rare circumstance as unless it was a known good un i'd be stripping it anyway...

[needabeetle]

I have used it once or twice on my E30 (M42 engine), but I put in 1/4 of a pint of diesel in, ran for 15 mins (till oil was nice and hot) then drained. It cleared some gunk, and when my dipstick thingy couldn't detect the oil level due to milky oil (when HG was going) it cleaned that out wonderfully.

I'm doing it again next time I change the oil, but it's not regular - that'll be the 2nd or 3rd time in just over 2 years, and I've done LOTS of oil changes in that time!

[Deleted]

Feb 18, 2010 14:11:37 GMT mdh said:

Feb 18, 2010 7:46:16 GMT nightmaresracing said:

a lot of people say engine flush ruins engines this is complete rubbish all engine flush will do is show up a problem if the engine is already ruined sometimes the crud buildup in an engine can mask what is really wrong with it and once all that crud has been removed it will start to reveal the underlying problem . I have flushed through lots of engines with no problems . at least if it does show up a problem you will have a nice clean engine to rebuild

It ruined 3 Rover V8's of mine.
This was the flushing stuff that you add to your oil.
All 3 developed major oil leaks afterwards.

Ive been told that old style flushing oil, where you replace yoor old oil with it run for 5 mins then drain, is better.

then you probably had 3 really leaky rovers with gunk built up round the oil seals that was stopping them leaking so they would have needed seals anyway;)

[mdh]

Feb 18, 2010 15:35:56 GMT nightmaresracing said:

Feb 18, 2010 14:11:37 GMT mdh said:

It ruined 3 Rover V8's of mine.
This was the flushing stuff that you add to your oil.
All 3 developed major oil leaks afterwards.

Ive been told that old style flushing oil, where you replace yoor old oil with it run for 5 mins then drain, is better.

then you probably had 3 really leaky rovers with gunk built up round the oil seals that was stopping them leaking so they would have needed seals anyway;)

I was told (after buggering the engines ) that the wynns and similar stuff contains strong detergents to break down the crud and that this can attack the seals.

Sure the seals were probably past thier best, but theyd have gone on for many more miles if I'd not used the flusher.

I for one wont use it again.

[Deleted]

Feb 18, 2010 15:55:26 GMT mdh said:

Feb 18, 2010 15:35:56 GMT nightmaresracing said:

then you probably had 3 really leaky rovers with gunk built up round the oil seals that was stopping them leaking so they would have needed seals anyway;)

I was told (after buggering the engines ) that the wynns and similar stuff contains strong detergents to break down the crud and that this can attack the seals.

Sure the seals were probably past thier best, but theyd have gone on for many more miles if I'd not used the flusher.

I for one wont use it again.

i know what your saying i think i would have to think twice about using it on an engine like a rover v8 or any engine that has a reputation for leaking lots