Hello all

I was told it is unecessary to flush your engine if you use synthetic oils as there is no sludge build up and was given the impression flushing ones engine might potentially be bad.

Should I just Empty Oil and Refill or Flush it?

If an engine is flushed from relatively new it can have advantages...
However flushing an engine which hasn't been done for some time or ever can dislodge crap and cause further problems... blockages etc..

Then couldn't it be flushed again afterwards?

What if an older engine was flushed for a long time before refilling with oil, would that be ok?

the theory about flushing old engines is that over time the build up of deposits actually helps to create a seal, or protect parts, or prevent leaks, or reduces friction and wear of components blah blah blah and if you remove the deposits of crap you'll cause oil seal leaks, and premature engine wear, also performance will suffer and the engine wont run as smoothly. (even local motor factors have said it)

here's what i know, i've always used engine flush on every car at every service. that includes cars that have high milage and probably never had a flush before in their lives. i've never seen it cause a problem once and it feels good to see thick black crap come out. on an old 1.3 escort i noticed a definate improvement in the engine running after giving it the first good flush of its life, the tappets were less noisey, the engine seemed to rev more freely, fuel economy improved, and despite the horror stories nothing bad happened, no leaks, no burning oil, nothing. i gave that engine 2 cans of engine flush every 6 months for 2.1/2 years and 50k, it never caused a problem.

if you ask me the engine deposits are better off in my oil bucket than in the engine. the urban myth of damage from using flush is just that, a myth. the only real danger is blockage of oil ways if a lot of crap gets dislodged and then gets stuck on its way to the sump (usually in the head oil ways). thats why i use 2 cans of engine flush and do it with the engine red hot.

To be honest I wouldn't...
some of the oilways in an engine don't take much to get blocked, no matter how many times you flush it. Its one of those unknown quatities really. since you cant see inside you'll not know if its done you any good or bad until something goes wrong.
Engine flush is vey thin base compared to oil so running your engine for a longer period wouldn't be advised..

i knew a lad who stuck some in his car and drove it for days before i found out. he said he wanted to give it a good clean out. what a noob. he wouldnt let me drain it either, i offered to do it for free as well.

dave flushes with 50% cheap 20w50 oil 50% petrol, cleand old filter out with petrol and refit for flushing, then drain it for hours, then put a ltr of new oil through to remove flush.

i like that idea

why talk about yourself in the third person?

jug said:

why talk about yourself in the third person?

Click to expand...

because usaly someone else put it up and writes it like that

ah, makes perfect sense