I would just add a pint if diesel to the engine oil and run at high idle for 20 minutes then drain, cans of oil flush are pretty much the same thing.
Always worth a gearbox oil change, get the filling bung out before draining
The caris a 1999 audi a4, 90bhp 1.9tdi, 188k on it, just getting that out the way!
I changed the oil in about may or june last year because it was thick, black, and if it got on your hands it just wouldn't come off, so warmed
the engine a bit, drained, left the plug out while I changed the filter, filled, ran the engine, left a few minutes to settle, checked the level and
it was still just as black...
I'm considering doing the gearbox oil now, and doing theengine oil again. Worth putting any sort of flushing stuff in? I'm seeing stuff that
says its not a good idea. Stuff about engines being ruined by flushing
It can dislodge rubbish, move it somewhere important and stuff your engine.
I would just add a pint if diesel to the engine oil and run at high idle for 20 minutes then drain, cans of oil flush are pretty much the same
thing.
Always worth a gearbox oil change, get the filling bung out before draining
I would drain the oil but leave the filter, bung in some cheapo oil, run for a short time so it gets hot, drain that and do a proper oil change.
I think the issues with flushing is that all the crud gets loosened up and then goes around the engine. In reality there should be little crud if good
oil has always been used, but oil is often skimped with.
VAG extended service intervals are to blame change oil run the car for 2000 miles ,. Stick some cheap low SAPs fully synthetic in. Then run it for
another c2000 and then go back to normal intervals.
Synthetic oils tend to break down deposits in the oil ways because they inherently act as solvents.
Mineral oils and to a lesser extent semi-synthetics depend on detergent and anti-varnish additives, in addition the mineral oil breaks down when
exposed to turbo termperaratures causing the oil to get "manky".
Mineral oils and semi-synthetics tend to turn black instantly when put in a dirty engine, but drop the black sludge as the oil detergents become less
effective
[Edited on 28/3/14 by britishtrident]
quote:
Originally posted by cliftyhanger
I would drain the oil but leave the filter, bung in some cheapo oil, run for a short time so it gets hot, drain that and do a proper oil change.
I think the issues with flushing is that all the crud gets loosened up and then goes around the engine. In reality there should be little crud if good oil has always been used, but oil is often skimped with.
You could change or flush the oil lots of times and you will still have black oil on the dipstick it's a diesel and high mileage just change the oil and filter at regular intervals with decent and correct spec oil and it will be fine.
+1 for flushing with cheapo oil
quote:
Originally posted by ian locostzx9rc2
You could change or flush the oil lots of times and you will still have black oil on the dipstick it's a diesel and high mileage just change the oil and filter at regular intervals with decent and correct spec oil and it will be fine.
We use Forte Motor Flush in every diesel we service and it works well. Cleans the poo and keeps it in suspension while you drain it. Stick it in run
for 15-20mins and drain. Certainly seems to work as even the drain bucket ends up clean.
The big issue with a car that hasn't been regularly serviced is that a cheap flush can just flush the crap down into the sump and block the
pick-up.
lovely, cheers for the info!
strange that you're saying don't do it because it can dislodge stuff, but surely thats the point? clean out the oil passages, stop them
blocking up?
i think the car had actually been serviced fairly regular, at audi the local dealer, stamps in the book and everything, every year, until about 4
years ago, then nothing.
yes i agree not to spend on it (but nick, you're rebuilding a french hatch back?! 
), but as it is, its a solid car, engine doesn't burn
any oil, gives me 50mpg, runs on veg oil, and i want to keep it this way as long as i can. if a flush would help for a few extra quid, i'd give
it a shot.
but, cheap oil it is! i'll leave the current filter in, less messy, and its only been in for about 5000 miles i think?
another question, any suggestions on which cheap oil? halfords cheap enough? is there cheaper?
Local car parts shop, mine does 10w40 for £15 for 5 litres. Local adsa/tractors superstores have cheap oil too.
quote:
Originally posted by blakep82
lovely, cheers for the info!
strange that you're saying don't do it because it can dislodge stuff, but surely thats the point? clean out the oil passages, stop them blocking up?
i think the car had actually been serviced fairly regular, at audi the local dealer, stamps in the book and everything, every year, until about 4 years ago, then nothing.
Never seen the point of a warm drain. Flush yea, drain no. If you run the engine and get it a bit warm all you're doing is chucking the oil into
far off places which warm or not will take time to return from. Last time it was put away it was put away at full temp and left to drain completely
into the sump, just crack the sump plug and let it drain for longer. Flush it if you fancy but I've never bothered and never come unstuck even
with high mileage long duration diesel?
There's the argument that it will suspend stuff in the bottom of the sump. which I see, but having always drained warm (was always told to by
longer-in-the-tooth people and did, despite not really seeing the point) my 23 year old tin top,. on pulling the sump off last month I found all sorts
in the bottom which clearly hadn't been lifted despite an oil change 1K earlier. <shrugs?
[Edited on 29/3/14 by coyoteboy]
Your right... as long as you leave it long enough. If time is limited then best to drain hot and if using flush, drain it hot so the crap it's lifted is still in suspension. Take a drained sump off and you'll be surprised how much oil is still there and thats the bit the crap will settle out into.
There was mostly piston parts in the sump when I took mine off, displaced the oil 