Changing Oil Without Changing Filter
Discussion
Hi, yesterday I changed my engine oil on a used car I bought (not sure when it was last done). When coming to change the filter, I found that the filter I ordered was the wrong one (whoops). Ordered the correct one and will be installing it tomorrow.
Just wondering if running new clean oil on an old filter could have a noticeable negative effect on the new oil. Only concerned because the old filter was black with some "sludge" build up in the filter (looked rather old).
Shouldn't make any difference, right?
Just wondering if running new clean oil on an old filter could have a noticeable negative effect on the new oil. Only concerned because the old filter was black with some "sludge" build up in the filter (looked rather old).
Shouldn't make any difference, right?
DSykes said:
Hi, yesterday I changed my engine oil on a used car I bought (not sure when it was last done). When coming to change the filter, I found that the filter I ordered was the wrong one (whoops). Ordered the correct one and will be installing it tomorrow.
Just wondering if running new clean oil on an old filter could have a noticeable negative effect on the new oil. Only concerned because the old filter was black with some "sludge" build up in the filter (looked rather old).
Shouldn't make any difference, right?
Well yes, the new oil will be mildly contaminated. Wouldn't really matter that much but don't do it again sort of thingJust wondering if running new clean oil on an old filter could have a noticeable negative effect on the new oil. Only concerned because the old filter was black with some "sludge" build up in the filter (looked rather old).
Shouldn't make any difference, right?
some tribologists advocate 2 oil changes per filter. others argue to definitely leave some 'activated' oil in the system.
i believe the evidence points to regular oil changes and ensuring oil level is never low and you're good to go.
even some of those pictures of "my good, look at this engine not serviced in 40,000 miles, just topped up" don't look that bad. engines with no oil, less good.
i believe the evidence points to regular oil changes and ensuring oil level is never low and you're good to go.
even some of those pictures of "my good, look at this engine not serviced in 40,000 miles, just topped up" don't look that bad. engines with no oil, less good.
Baldchap said:
Does anyone know if the Americans, with their obsession with silly short change intervals, just do oil between services or do filters too?
Don’t think they do that any more. My us car is the same servicing in the uk as us, except severe weather - been -30c in Minneapolis today...Tony1963 said:
GreenV8S said:
What is 'activated' oil and why would you want that rather than fresh, clean oil?
I was wondering too! As far as I know there’s no such thing. New oil is as good as it gets. Activated oil is contaminated oil!
OP, if it were my car for the price of peace of mind I would just do another (admittedly unnecessary) oil & filter change & put it down to experience while getting another spare correct filter so the same mistake doesn't happen again.
Bitog forum provides hours of nerdy fun on this. sad, but at least those guys have lots of oil analyses to provide some facts.
activated is just used (ie heated).
as for 'contaminating' new oil with old that's questionable. for people on this forum, especially some earlier posters, most oil is being changed way too early. 3500 is technically about a quarter through it's life, maybe less depending on cycles or quality of oil. multi-million pound machines don't get the OCIs of some cars here.
i'm a mix up myself. i refresh my oil early via a suction pump. i do it earlier than facts suggest is necessary, but it's my indulgence. I feel good topping up the tbn and removing some acids and 'bits'
activated is just used (ie heated).
as for 'contaminating' new oil with old that's questionable. for people on this forum, especially some earlier posters, most oil is being changed way too early. 3500 is technically about a quarter through it's life, maybe less depending on cycles or quality of oil. multi-million pound machines don't get the OCIs of some cars here.
i'm a mix up myself. i refresh my oil early via a suction pump. i do it earlier than facts suggest is necessary, but it's my indulgence. I feel good topping up the tbn and removing some acids and 'bits'
the bad stuff should be still trapped in the filter , some old black oil will always remain in the engine anyway so yeah youve mixied it with a few cc of extra old oil , change the filter when you get the new one and carry on
dare i say many iffy motor dealers will have given a filter a wipe with a rag and just changed the oil on many thousands of cars
dare i say many iffy motor dealers will have given a filter a wipe with a rag and just changed the oil on many thousands of cars
eldar said:
Don’t think they do that any more. My us car is the same servicing in the uk as us, except severe weather - been -30c in Minneapolis today...
Many years ago Americans changed their oil every 3000 miles but not the filter. The oil and filter change was every 6000 miles.Oddly enough I was checking the service interval for a 2018 Mini. I came across an American Mini site which states a Mini should have an oil and filter changed every 4500 miles.......nothing really seems to have changed very much.
One place I worked, a lot of the others had worked in AC Delco's filter factory. They reckoned that the particulates from the old oil actually helped reduce the hole size in the filter thus giving increased filtration. In other words, only on the second oil change is the filter actually filtering as it should.
I can see what they are saying, but not saying its right or wrong.
I can see what they are saying, but not saying its right or wrong.
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