sulli

What oil next, based on the following?

20/11/98: 2953 miles, oil change 1st service
17/03/99: 10,248 miles, 10w40 semi-synth
130/5/99: 15,215 miles, Magnatec 10w40 semi-synth
27/08/99: 22,215 miles, 10w40 semi-synth
01/02/00: 30,246 miles, 10w40 semi-synth
20/06/00: 37,647 miles, 10w30 oil
17/11/00: 45,602, 10w30 oil
New short engine due to piston slap - warranty
25/04/01: 53,174, 10w30 oil
19/09/01: 60,973 miles, 10w30 oil
12/02/02: 67,867 miles, 10w30 oil
18/07/02: 75,163 miles, 10w30 oil
09/05/03: 90,095, 5w30 oil (f/synth?)
28/10/98: 92,479, Magnatec 10w40 semi-synth

Currently 94k - my plan was flush and run Castrol RS10w60. But based on the above, is there a more prudent option?

greasemonkey

RS, Mobil 1 Motorsport 15w/50, Motul 300V 15/50 are all good. When you say "flush", I wouldn't use engine flush or anything like that, just change the oil as per normal.

sulli

I was going to flush as semi and f/synth don't mix, so if using castrol 10w60, that's f/sytnh.

nom

Not sure about flushing myself either
Might be a plan - I'm not convinced that the two types of oil are that bad together, but I wouldn't risk it either.
A few hundred miles after flushing & refilling, I'd want to change the oil again as the flushing stuff isn't nice & I think you want that stuff in there even less than the mix. Which means it may well be simpler to just empty, refill, run for a few hundred miles, empty & refill again.
Lots of oil & filters

Ian D

Semi and fully synthetic oils DO mix, so I would not worry about a few hundred millilitres of semi left in the sump/oil ways - this will mix with fully synthetic fine.

If you were to mix semi and fully synthetic say 50/50 then you would lose a lot of the benefit of the fully synthetic but that's about it.

sulli

Someone said to me they never flush with Wynnes or the like, but buy a cheap supermarket thinnish oil, do a change, but not filter, run for a week, and then drain that for a decent oil - has a similar effect to flushing apparently, but kinder to engine??

greasemonkey

I've done something similar in the past after buying a new car, buying a gallon of cheap 10W/40 from B&Q for a fiver, cheap filter from Halfords and running it for a couple of days very steady driving before putting proper stuff in.

As has been mentioned above, there's no problem leaving a couple of hundred millilitres of semi synth inside the block when changing to full, it won't do any harm. Using engine flush in a hot-running turbo engine, however, can apparently do a number of undesirable things.

Jolly Green Monster

iTrader: (4)

Changed from semi to fully 15W50 Mobil 1.. no problems and about
29,000miles since (now @129,000miles).. I just drained and changed filter etc..

Make sure you prefill the filter...

The history of what oil it has run on made me cringe..

JGM

blitz imp reza

Don't think much of magnatec always go for fully syn, Can buy mobil 1 15/50 from local halfords for about £35! Have never flushed mine with aditives (smells like kerosene to me anyway, probably is?) don't think it would do the turbo seals anygood.

sulli

Is there a definitive answer to flushing for turbos? Particularly considering chequered oil history here.
I have always flushed, to get rid of crap in engine, and started afresh with a good oil, to be changed every 3k - filter then every 2nd change.
Should I forgo the flush on my turbo? if so, just run hot and drain, then refill, or go for the crap oil for a week scenario, to flush?

Jolly Green Monster

iTrader: (4)

Magnetec is not recommended in turbo engines due to the heat although I suspect Castrol might argue otherwise.

Flushing is not a good idea for any engine imho..

Just fill with 4.5litres of fully symthetic 15w50 or 10W60 and use a Subaru filter prefilled..

I change my oil every 7500miles.. and filter at the same time..

JGM

sulli

Any other recommendations? May just pop to Halfords now, and do today.
Subaru did a change 2k ago (probably using Magnatec) and changed the filter. Am I OK forgoing the filter change this time? Only reason I ask, is I cant get a Subaru filter today.