Opinions on oil flush

[Ginger pig]

Morning gents,

 

I just wanted to pick your brains re using a cheaper oil to refill initially; get up to temperature and then drain and refill again with 'Edge'.

 

I am just about to change the oil on my SE and I know that this has not been for some time on this car.

 

What are your thoughts?

 

I was looking at some cheap 'Carlube' which was within spec and cost £13 for 4L.

 

Mark

[jonwat]

Good idea, when you empty the cheep stuff out leave it draining overnight to make sure you get every drop. 

[Escape]

Even when draining overnight, there will sill be some cheap oil left in the pipes and the oilcoolers. So I wouldn't be to happy with cheap/unknown oil and rather use a good oil to fill and flush straight away.

But then I do pay less for a quality oil than the price you mentioned as cheap...

[cammmy]

It's pretty standard practice to do that. I did it on an MR2 that had grot looking oil upon purchase.

 

I'd put a few miles through it before draining, maybe a little bit of spirited driving too. AFAIK almost any oil that's better than the recommended API grade for the car will protect it just fine for that amount of time (we're talking <50 miles here). Where the more expensive oils shine is that they don't degrade as quickly; since longevity isn't a factor here I don't think that really matters.

 

The remaining oil in the pipes and coolers etc will dilute the oil you put into it. You could possibly shorten the next service inteval again to compensate? The same goes whenever you change the oil though. There will always be some amount of old degraded oil in there. It will be all new oil in there, just some of it won't be of the same quality. Is it better to run old good oil or new cheaper oil? That's another discussion in itself X-D.

 

I think the one thing that most people agree on is to never use an engine flushing agent.

Edited October 28, 2014 by cammmy

[Bibs]

Don't they thin the oil to aid it's removal, leaving residue therefore permanently thinner oil in the future?

[cammmy]

There's two reasons I'm aware of. Any sludge that gets dislodged can block oil galleries and that oil gets into the pores of the metal over time, if you clean this off with an agent, you have less protection until it builds up again.

[Bibs]

Thanks.

[glynherron]

I read on here some time ago that one owner cracks open the oil cooler pipes to drain the coolers and pipes and also so that the oil cooler unions never seize solid.

[Ginger pig]

Thanks guys.

 

Glyn,

 

Since the oil coolers and pipes look original; I would think that chances of successfully removing these would be next to impossible.

 

I think I will buy the cheap stuff and follow your advice above.

 

Mark

[glynherron]

Thanks guys.

Glyn,

Since the oil coolers and pipes look original; I would think that chances of successfully removing these would be next to impossible.

I think I will buy the cheap stuff and follow your advice above.

Mark

Hi Mark

I agree!!

[Jacques]

My take on this is, that the "cheap" oil may or may not be the same viscosity as the better Castrol Edge oil, or any other good oil, the new version even have som titanium particles (well sort of) in it, so they mix. Viscosity is not a problem in general, mixing a bit into the greater amount of the following oil.

Where I would think a bit about it, is the types of oil I mix. I spoke to Castrol and two other Companies some time ago, regarding oil and their additives. They all said do not mix diferent types of oil, eg. mineral - semi-synthetic and fully synthetic oils with each other.

Then there's the additives. Some use specific additives to obtain certain abilities in their oil, like the ability to withstand high temp, pick up contamination and keep it, surface-strength, expected average lifespan etc.

 

For the same reason, I never add some snake products into my engines, like fancy teflon stuff that is supposed to fill small crevices on metal surfaces, and thereby reducing drag. I've seen destroyed engines because oilfilters became quite blocked up by strange additives, being that the additives themselves or the Chemical mix of an oil and the additives. I'd never chance that. Nor in the gearbox. Fresh oil in that too every year, for the same reasons.

 

I've spoken to a few highly professional car tuners, and they said, that long-life oils are to be avoided. They lube differently and they can make sludge inside the engine, which in some cases advance an engine breakdown, especially on a tuned engine. Say a vw r32 with 730 biturbo hp engine.

 

Then everyone I've spoken to, said mix with same brand.

 

Now, that is going to be a bit hard, when intending to flush with a cheaper oil, to save some Money on oil going straight out almost immediately, when wanting to use same type oil - mineral, semi or fully synt. type.

 

Another thing is what temperature does to lubrication and other abilities to your engine oil. If say the engine oil is subjected to frost, the oil's added abilities like protection, begins to degenerate. Since there is really no sure way of knowing what exact state your oil is in, I would always change the oil - read flush it - and then add another fresh oil. I would never start the engine up on old unknown oil, even if I knew the exact type and brand.

 

I therefore concluded, that it takes some Money to flush it, and since it's something I'm doing seldom or maybe only once in your time with the car/engine, it's not really worth saving on exactly this. I therefore bought the same (expensive) castrol edge (no titanium at the time) for both flushing and oilchange afterwards.

It have to be said, that I trust the previous owner, that he did indeed use Mobil 1 all the time, and changed it very often.

I change it every 5000km or once per year, whatever comes first. If it have been put away with fresh oilchange and then subjected to frost, I always change it before startup in the spring. I always change oilfilter and only use original ones.

 

Just my two-pence,

Jacques

[Mark Blanchard]

Use Mobile 1 and change it every 3000 miles or less.  You'll have a nice clean engine.

[glynherron]

I'm in the process of rebuilding an s4s motor with 55000miles on the clock. It is costing far more money than anticipated. Even though I'm just a maths teacher and realise that the oil doesn't get everywhere to cause damage the percent cost of oil vs the cost of a rebuild is so small. Having been through this I would use good oil every time.

[Vanya]

I think a lot of stuff enthusiast owners go about doing is pure overkill. Flushing with cheap oil is pointless - as some have stated, there's still stuff left in the coolers. And you'd have to remove the coolers to get all the sludge out that's in there - with that you have the added fun of taking things apart without breakage, which as some have pointed out, is next to impossible.

 

The 910 engine is pretty hardy - there's lots of cars rolling out there with oil that probably hasn't been changed in 10 years and they're working ok, not that I condone that kind of thing.

 

Once a year with quality oil should be fine. 

 

Until I see a study with a sizeable sample group that says otherwise, I wouldn't be too worried about "flushing" and whatnot.

 

 

 

On a related note, sometimes I just feel sad changing oil every year - the stuff that came out of my V8 earlier this year was so clean it could have been reused in another vehicle for some time without issues... feels like a kick in the nads to the environment to throw away stuff which is probably still more than good enough. 

[cammmy]

I agree that a lot of what we do is probably over kill but I definitely wouldn't judge the oil solely on how it looks. That's just carbon from combustion. If you ran LPG, it would look like that no matter how long you left it in there but the oil still degrades. As previously stated, it's about the additives breaking down. So your oil might look clean, but it probably isn't anything like as good as it was when it went in. So don't feel bad on that account.

 

Re. Mixing of oils. If the car has a semi-synth or the cheapest full synth available in there when you buy it, does that mean you can't drain it and put a more expensive stuff in there? Because you are mixing types or different qualities?

 

Do we know the capacity of the lines and coolers vs total? I'd have thought that the advice about mixing oils would be around putting more of a 50/50 mix because you had half a bottle of semi-synth and half a bottle of full. How much of an effect does it have if it's only a small amount?

Edited October 29, 2014 by cammmy