I met a BMW owner last year that believed changing the oil filter was some sort

I've always changed the oil filter when doing an oil change. Is this necessary? Do some people only change the filter every other time, etc?

So the filter is basically squeaky clean.

Also, i sometimes am changing about half the oil, to adjust viscosity from summer/track to fall/winter/road.

e..g. i might have all 15w50 in for hot summer track days, and after 3+k miles, at the end of fall, pull out 5 qts and put in 5w40 o even 5w30 for the winter (yielding in effect 10w40, and with replenished additives)

For regular use, cut your filter open and see what it looks like.

Grant

Grant

gee-lenahan-at-gee-mail-dot-com

of conspiracy by the manufactures just to get you to spend money. Yet this same person would buy the overpriced oil at the BMW dealer for his oil change, go figure

so it is easy to see where someone might arrive at the thinking that an oil change doesn't have to include a filter change.

And honestly, it doesn't.

The filter is large and has plenty of capacity, but even if it didn't it doesn't have to hold much stuff. I mean if the filter was in any danger of getting too full to flow oil the engine would already be in pieces from the failure of whatever was shedding material enough to raise any concern about the filter's ability to flow oil.

Once or twice I've changed the oil without changing the filter when I realized I didn't have a filter and didn't want to postpone the oil change. For sometime now since to change the oil means having to drive 30 miles to the office and use the shipping bay for my garage if I find I do not have a filter it means essentially postponing the oil change for a week. Due to my schedule sometimes a week's postponement is not doable.

After one or two of these oil change sans the filter change I did make it a point of before leaving the house to double check that not only did I have all the tools/equipment and the sufficient oil I needed that I had a new filter with an o-ring and drain plug sealing ring too.

But save for one or two times every other time with the Boxster and the 996 I've changed both the oil and the filter. Oh, once I did the GTO's oil and found I didn't have a wrench with which to remove the filter, but I found out only after I had opened the drain plug. So I left the filter in service until I picked up a filter wrench then changed the filter after the oil change.

Your oil filter contains how much of the total oil in the system? So if you change the oil only, how much of the benefit of an oil change do you get? What is the last ~10% worth? Not implying you should do it all the time but for a 3-4k oil change interval doing it every other time, would it be better to extend the interval or skip the filter?

meh.

Grant

gee-lenahan-at-gee-mail-dot-com

the filter is due to be changed. If one develops a habit of changing the filter every time the oil is changed there's no missing a filter change.

Is that when you change the filter you can inspect the filter element for metal, which typically gives you early warning to problems.

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Boxsterra
Is that when you change the filter you can inspect the filter element for metal, which typically gives you early warning to problems.

Of course, you'll want to change the filter every time during the break in period, but I don't think that's where you're at.

Whether or not you change the filter every single time, props for doing it yourself. How I picture shops chaning oil and why I always have to do it myself:

The main reason I asked is that I'm away from my tools for some months and want to do a change due to the large mileage I'm putting on the car during that time. I was going to try an indy, but I like knowing what's been done to the car as much as I can (plus, I enjoy doing the work). I have space, just no tools. So I'll buy the couple of tools needed (priciest of which will be a set of ramps for $50). I thought I'd skip the filter this one time to save a little on tools. I've always wanted to try one of those strap filter wrenches though, so I went ahead and bought one.

That whole thought process just got me to wondering about the need of doing the filter each time. I like Marc's comment about the added complication of keeping track of when the filter's due. I hadn't thought of that, and I'm sure I would end up forgetting.

This is an interesting subject. I have never changed my oil without changing the filter, but always noticed that some manuals state filter changes every second time. I always halve the intervals, and since it is kind of a pain to change the filter on the Boxster, particularly the 981, I start to wonder if it would be fine changing the oil every 5k, and the filter every 10k. This would still be halving the filter interval. I don't see a problem remembering when to change the filter since the filter changes would always be on the 10k's. I'm not trying to cheap out, it's just such a pain changing the filter.

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gedwin
This is an interesting subject. I have never changed my oil without changing the filter, but always noticed that some manuals state filter changes every second time. I always halve the intervals, and since it is kind of a pain to change the filter on the Boxster, particularly the 981, I start to wonder if it would be fine changing the oil every 5k, and the filter every 10k. This would still be halving the filter interval. I don't see a problem remembering when to change the filter since the filter changes would always be on the 10k's. I'm not trying to cheap out, it's just such a pain changing the filter.

Is the filter on the 981 in a different position or covered up that makes it more difficult to change than on previous generations?

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Guenter in Ontario


Is the filter on the 981 in a different position or covered up that makes it more difficult to change than on previous generations?

Generally the same position. 987.2 sits higher up than 986, so it is harder to reach. 981 is same as 987.2 position wise, but the frame is closer to the canister, making it more difficult to finagle it out and dumps oil all over.

It's also time (every 12 months, if I remember). It's pretty easy to get out of sync with nice round odometer readings.

My best advice would be to consult the owners manual and follow up with the dealer service department to see if there is anything official from Porsche regarding oil filter change interval.

It could be Porsche has rescinded that change the filter only every other oil change guideline and now requires the filter be changed with the oil.

As long as Porsche doesn't forbid skipping the filter change when the oil is changed if you want to do this it is your car and you can do as you wish. I would urge you to reconsider but the oil filter has plenty of capacity.

" I would urge you to reconsider but the oil filter has plenty of capacity."

Part 1 does not follow from part 2 of that sentence. Regardless of where the facts lie, one should change!

Grant

Grant

gee-lenahan-at-gee-mail-dot-com

not forbid it in the newer model owners manuals or by a tech note or TSB or whatever, the OP is free to do as he wants which is I gather is skipping the oil filter change every oil service.

Well, he's considering doing this.

I would urge him to reconsider, that is do as he has been doing and change the filter every oil change, but the filter has enough filtering capacity to handle being left in service through two oil changes. I mean at one time Porsche believed for example in my 02 Boxster's case the filter could suffice for 30K miles with 15K mile oil changes I think the filter can handle 10K

The filter has handled this more than once, 2 maybe, doubtful 3 and definitely not 4 or more times, I'm sure, in my Boxster when a few times I have not done a filter change at the same time I did an oil change. Also, essentially the same filter (nearly the same size anyhow) handled 10K miles (at least once) in my 996 when I missed a 5K mile oil/filter service and the oil and filter were left in service for 10K miles. The factory service manual calls out a 10K mile oil/filter service so I was not violating any guideline or rule other than my own 5K mile oil/filter (well, filter with very very few exceptions) changes.

Just seems like the right thing to do.

BarryL
2002 2.7 base tip
165K miles

...exceptions) for both of my cars and in fact for my cars going back some time, those car for which synthetic oil was specified. For car engines that used mineral oil I followed a shorter change interval.

I think the oil/filter change schedule I have followed over the years and miles is one of the major reasons I have enjoyed such good life from my cars, the Boxster now with over 268K miles, and the 996 with over 109K miles. But I also got over 120K miles out of my VW Golf TDi and way over 120K miles out of my Mustang GT. While I've owned other cars and one truck I drove them a lot fewer miles.

But with none of my cars have I had any engine issues related to oil. As I have pointed out numerous times the oil is the sacrificial part, or item, in the engine/oil partnership. Better to discard oil that has some (possibly) additional "life" left than to run the risk of running it too long.

But i always change at roughly 1/2 the manufacturer's spec. As a bud who formulates oil for a mahjor reminds everyone who will (or wont) listen, "everyone's driving qualifies as severe service".

Ive kept cars for up to 300k. I have never had a lubrication related failure, or even any significant wear, really.

For my track driven cars i cut even the shortened interval (typically to 3-4k, including 3-4 trackl events plus normal use).

Adn, as i keep harping on, use oil that suits YOUR use, not some theoretical norm.

As we all know, i'm nto normal :-)

back to the OP question,. its still not clear why one would need to change the filter every time in an accelerated change routine. I dont, and i dont see any fact-based reason to do so.

Grant

Grant

gee-lenahan-at-gee-mail-dot-com



Edited 1 time(s). Last edit at 06/25/2013 12:02PM by grant. (view changes)

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grant
But i always change at roughly 1/2 the manufacturer's spec. As a bud who formulates oil for a mahjor reminds everyone who will (or wont) listen, "everyone's driving qualifies as severe service".

Ive kept cars for up to 300k. I have never had a lubrication related failure, or even any significant wear, really.

For my track driven cars i cut even the shortened interval (typically to 3-4k, including 3-4 trackl events plus normal use).

Adn, as i keep harping on, use oil that suits YOUR use, not some theoretical norm.

As we all know, i'm nto normal :-)

back to the OP question,. its still not clear why one would need to change the filter every time in an accelerated change routine. I dont, and i dont see any fact-based reason to do so.

Grant

That's exactly what I am questioning at this point. If I change the oil every 5k, and the filter every 10k, I am still changing the filter at an accelerated change routine, per Porsche requirements. The only consequence would be that about 1 pint or less of oil would remain in the engine for 10k miles, which is Porsche's required oil change interval.

I haven't decided on this yet. And I come from an "oil and filter every 2K" background, back in the mineral oil days, so I was always for "better safe than sorry". But I am reaching a point where I should at least be questioning old thinking.

Yes, there's one pint of old oil in there. But the issues with old oil are:

1. shear
2. sludge
3. reduction in TBN (ability to buffer acids)
4. Loss of additives (including bases above)

Putting in 17/18th new oil fixes, 4,3,and 95% of 1 and 2

The filter is obviously in its window, and you took out dirt with the oil.

Grant

Grant

gee-lenahan-at-gee-mail-dot-com