Weird problem...

[December]

I've been away for the weekend and my father changed the engine oil without changing the oil filter and drove around about 17km using the new oil and the old oil filter. So i've just bought a new one (oil filter) and i don't know what to do.
He used Mobil 1, 10W-40 ( 505.00 ) for my 81KW Leon :|.


Should i let the oil drain again before changing the oil filter ?
Should i not change the oil filter at all and change everything 4~5 months from now ?
Should i try changing the oil filter without draining the new oil allover again ? Is that even possible ?

After draining the new oil and changing the filter is it ok if i pour the same oil back into the engine ? :|

You see the mess i'm in; what should i do ?

 

[dj_hektik]

mobil 1 is what, 10 quid a litre? if you are willing to spend 40 quid change the oil again.

i think that's over the top, though. I wouln'd bother too much - keep the filter till next oil change. If you want to pamper your car, though, you can collect the oil in a VERY clean container and re-use it after fitting the new filter. 10 mins out of the car won't change the oil.

make sure the engine is cold first so you don't burn yourself/melt any plastic containers.

take care

 

[December]

Well i lost my patience yesterday and went ahead and changed the oil filter without draining the oil; and then drove around about 20km just to see how it goes and i didn't notice any problems so i guess all is well now.

But just to be on the safeside i'll change the oil sooner rather than later; maybe 5~6 months from now or @ 7000km (Mobil 1 says next oil change should be after 15.000km) >_<;

 

[Fluke]

I don't see how you can have done any harm or why you should change oil again sooner than you otherwise would. The only thing is you will have lost a small amount of oil in the old filter when replaceing it, so check your oil level and top up if necessary.

 

[December]

Yup; i had 1L of oil to spare anyhow as i bought 5L of Mobil 1 and only needed 4.

 

[iannez]

as soon as you started the car and the oil passed through the filter it will have become contaminated and about as good as the oil that was drained. the filter will be choked reducing oil flow. bite the bullet mate, use a decent flush then drain the oil and fit new filter.

 

[Muttley]

iannez wrote

as soon as you started the car and the oil passed through the filter it will have become contaminated and about as good as the oil that was drained.

Contaminated with what?

The oil filter is there to filter out solids, putting new oil through it won't magically dissolve the solids or anything.

You change the oil because it wears out, becomes thinner and loses its performance due to mechanical damage (getting mashed between hot bits of metal) and oxidation (getting hot). This change in its composition is not something that can be "caught" by the new oil, like some kind of lubrication disease.

There will have been a small amount of old oil left in the filter, but this shouldn't dilute the new oil to any serious extent. Simply make sure you change the oil and filter again at the proper interval.

the filter will be choked reducing oil flow. bite the bullet mate, use a decent flush then drain the oil and fit new filter.

Fit a new filter, yes, it gets blocked and eventually the bypass valve will open, saving the engine from lubrication failure but removing the filter from the circuit. You don't want that to happen.

If you change the oil at the recommended service interval, or better, at 5K intervals, you don't need to flush. Flushing is for high-mileage engines that have been neglected.

 

[December]

Thanks ^_^; As i said i changed the oil filter aswell now so i guess its all good.

 

[iannez]

lol. i will never bother changing my filter again if thats the case. oil is good for about 2 year or 20 k before it brakes down so why chang it before hand. its a precation and if they wernt changed together it pretty much defeats the object doesnt it. the new oil is drawn through the old filter passing over and picking up micro fine particals and oxidants. the filter only holds the big lumps. the flush breaks down any crap caused by moisture mixing with oil (stops hydralic tappets sticking etc) and most flushes now contain oil seal replenisher and coat all internal parts with ptfe so when you drop the oil it doesnt stick to anything and just about all the oil is removed. try filling 2 glasses with oil but first swill one round with some engine flush. then empty both glasses. youll get the idea. dont understand why you disagree with this as you seem realy clued up.

 

[Muttley]

iannez wrote

lol. i will never bother changing my filter again if thats the case. oil is good for about 2 year or 20 k before it brakes down so why chang it before hand.

Oil starts to break down as soon as the engine is started. The aim is to change the oil before it becomes too degraded to protect your engine. That interval is up to you: you could get some benefit from changing it every week, but it would be expensive and time-consuming. Most people stick with the manufacturers recommended intervals: some of us change more frequently, at 5k miles.

its a precation and if they wernt changed together it pretty much defeats the object doesnt it.

No, and that was my point. The filter is there to catch gross contaminants before they get ground into the bearing surfaces and cause accelerated wear. It doesn't matter how new or old the oil is, the filter will still catch all the contaminants it can - oil on the output side of the filter will be just as clean whether it's new oil or old oil.

The oil has to be changed because the long-chain molecules that give it its character are slowly broken down by the mechanical mincing action of the engine. Oxidation products build up as well, formed at hot-spots, especially at start-up and shut-down.

the new oil is drawn through the old filter passing over and picking up micro fine particals and oxidants.

Nope. Micro-fine particles will not be held by the filter and oxidants are dissolved or suspended in the oil in the first place - they are what turns the oil black. The oil will be black within a few hundred miles of any change as the oil begins to oxidise - take a look at your dipstick.

the filter only holds the big lumps.

Exactly. Oil on the output side of the filter will contain whatever contaminants the filter can't retain. The filter won't hold onto them with old oil and release them into new oil.

the flush breaks down any crap caused by moisture mixing with oil

What kind of crap would that be then? (be specific) . . .

(stops hydralic tappets sticking etc) and most flushes now contain oil seal replenisher and coat all internal parts with ptfe so when you drop the oil it doesnt stick to anything and just about all the oil is removed. try filling 2 glasses with oil but first swill one round with some engine flush. then empty both glasses. youll get the idea.

I think you've been taken in by the claims of the marketing men. It doesn't matter if a little of the old oil remains in the engine, it will be an insignificant proportion of the total oil content and the fresh oil will not be compromised any more than it will be by the first engine start,

 

[iannez]

The oil filters on most engines today have been downsized to save weight, cost and space. The "standard" quart-sized filter that was once common on most engines has been replaced by a pint-sized (or smaller) filter. You don't have to be a rocket scientist to figure out that a smaller filter has less total filtering capacity. Even so, the little filters should be adequate for a 7,000 mile oil change intervals -- but may run out of capacity long before a second oil change at 15,000 miles.

Replacing the oil filter every time the oil is changed, therefore, is highly recommended.

An engine's main line of defense against abrasion and the premature wear it causes is the oil filter. The filter's job is to remove solid contaminants such as dirt, carbon and metal particles from the oil before they can damage bearing, journal and cylinder wall surfaces in the engine. The more dirt and other contaminants the filter can trap and hold, the better.

In today's engines, all the oil that's picked up by the oil pump is routed through the filter before it goes to the crankshaft bearings, cam bearings and valvetrain. This is called "full-flow" filtration. It's an efficient way of removing contaminants, and it assures only filtered oil is supplied to the engine. In time, though, accumulated dirt and debris trapped by the filter begin to obstruct the flow of oil. The filter should be changed before it reaches this point, which is why the filter needs to be replaced when the oil is changed.

If you wait too long to change the filter, there's a danger that it might become plugged. To prevent this from causing a catastrophic engine failure due to loss of lubrication, oil filters have a built-in safety device called a "bypass valve." When the pressure drop across the filter exceeds a predetermined value (which varies depending on the engine application), the bypass valve opens so oil can continue to flow to the engine. But this allows unfiltered oil to enter the engine. Any contaminants that find their way into the crankcase will be pumped through the engine and accelerate wear. An oil flush should be used periodically to get rid of contaminants and sludge that build up in the crankcase.

 

[December]

 

[Muttley]

iannez cut-and-pasted

http://autos.yahoo.com/owning/maint...lters+&+Oil&topics=qaairfil
qalubric
qaengoil

<a lot of stuff that restates and amplifies what I had already written>

So, you agree with me then that changing the oil filter a few KM after the oil change should have no effect on the engine or the new oil? After all, it's not as though the filter was left in placed until the next change was due.

Just to restate my position, in case it has become unclear: Always change oil and filter at the same time. If (as in Carpathian's case) you discover that the oil has been changed for you but the filter hasn't, change the filter immediately; provided only a few miles have been covered neither the oil nor the engine will have suffered.

As I said upthread, a filter left in too long will eventually clog to the point that the bypass valve opens, allowing unfiltered oil to circulate as a last-ditch defense, poor oil being better than no oil. This is to be avoided by changing the filter, and oil, at the prescribed intervals.

Incidentally, the spin-on, canister filters each contain a fresh bypass valve, which is another reason why you should buy a good-quality filter.

 

[December]

yup; 17km only

 

[iannez]

thought it was plain to see that i cut and pasted as i would never prattle on like this. see previous posts. anyway what ever i've had enough now. its up to who ever post what advice to take. got better things to do with my time than to argue with ppl. in futre if you dont agree with what i post just ignore it.

 

[dj_hektik]

thought it was plain to see that i cut and pasted as i would never prattle on like this. see previous posts. anyway what ever i've had enough now. its up to who ever post what advice to take. got better things to do with my time than to argue with ppl. in futre if you dont agree with what i post just ignore it.