Pointless oil changes?

And I thought my Forester was using a lot at a quart every 800 miles before I replaced the engine... I guess not!

I would still change it, but maybe extend the intervals a bit. Otherwise you never have completely fresh oil to start with.
I definitely feel more comfortable with this than with total forsaking oil changes.
 
I would consider that it may be time for a new car
I have other vehicles, but we've been together a long time. I have a parts-car that I've already pulled the transmission from and am disassembling the engine of in situ for rebuild. My ex offered to take it and leave me with her much newer car, but I said no.
 
I don't think any Nissan Sentra needs an oil change every 3,000 miles. A change every 5,000 miles would be more appropriate.

In this situation I think the answer depends somewhat on whether the engine is burning oil or leaking oil.

If it's leaking oil the oil is being constantly drained and replaced and the only thing to do would be to replace the filter occasionally, say every 10,000 miles. For good measure you might change the oil at very long intervals, say with every other filter change.

If it's burning oil, it might be getting past the rings or past the valve seals. If it's only getting past the rings, my theory is that some of the bad stuff in the oil wouldn't get past the rings, so the oil should be changed at a normal interval which still would be every 5,000 miles. But if the oil is fairly clean looking when you drain it I'd go for an oil and filter change every 10,000 miles. It would be interesting (but probably not cost effective) to have the oil analyzed at the next change.

If it's burning oil I can't imagine the catalytic converter tolerating that for very long, so rebuild that engine. If it's smoking, do us all a favour and rebuild the engine.
 
This could definitely be an interesting experiment. Some engines (including mine) tends to increase the oil consumption at the begining of using Valvoline Restore and Protect, so that is something to be careful with.

Also, I am curious how does adding 7 quarts of oil in 3000 miles to an oil pan with 3 quart cap
I don't think any Nissan Sentra needs an oil change every 3,000 miles. A change every 5,000 miles would be more appropriate.

In this situation I think the answer depends somewhat on whether the engine is burning oil or leaking oil.

If it's leaking oil the oil is being constantly drained and replaced and the only thing to do would be to replace the filter occasionally, say every 10,000 miles. For good measure you might change the oil at very long intervals, say with every other filter change.

If it's burning oil, it might be getting past the rings or past the valve seals. If it's only getting past the rings, my theory is that some of the bad stuff in the oil wouldn't get past the rings, so the oil should be changed at a normal interval which still would be every 5,000 miles. But if the oil is fairly clean looking when you drain it I'd go for an oil and filter change every 10,000 miles. It would be interesting (but probably not cost effective) to have the oil analyzed at the next change.

If it's burning oil I can't imagine the catalytic converter tolerating that for very long, so rebuild that engine. If it's smoking, do us all a favour and rebuild the engine.

acity works? I guess that is topping up every 200 miles or so?It
I don't think any Nissan Sentra needs an oil change every 3,000 miles. A change every 5,000 miles would be more appropriate.

In this situation I think the answer depends somewhat on whether the engine is burning oil or leaking oil.

If it's leaking oil the oil is being constantly drained and replaced and the only thing to do would be to replace the filter occasionally, say every 10,000 miles. For good measure you might change the oil at very long intervals, say with every other filter change.

If it's burning oil, it might be getting past the rings or past the valve seals. If it's only getting past the rings, my theory is that some of the bad stuff in the oil wouldn't get past the rings, so the oil should be changed at a normal interval which still would be every 5,000 miles. But if the oil is fairly clean looking when you drain it I'd go for an oil and filter change every 10,000 miles. It would be interesting (but probably not cost effective) to have the oil analyzed at the next change.

If it's burning oil I can't imagine the catalytic converter tolerating that for very long, so rebuild that engine. If it's smoking, do us all a favour and rebuild the engine.
This could definitely be an interesting experiment. Some engines (including mine) tends to increase the oil consumption at the begining of using Valvoline Restore and Protect, so that is something to be careful with.

Also, I am curious how does adding 7 quarts of oil in 3000 miles to an oil pan with 3 quart capacity works? I guess that is topping up every 200 miles or so?
After an oil change, the usage increases to about 1qt per tank of gas.
 
I don't think any Nissan Sentra needs an oil change every 3,000 miles. A change every 5,000 miles would be more appropriate.

In this situation I think the answer depends somewhat on whether the engine is burning oil or leaking oil.

If it's leaking oil the oil is being constantly drained and replaced and the only thing to do would be to replace the filter occasionally, say every 10,000 miles. For good measure you might change the oil at very long intervals, say with every other filter change.

If it's burning oil, it might be getting past the rings or past the valve seals. If it's only getting past the rings, my theory is that some of the bad stuff in the oil wouldn't get past the rings, so the oil should be changed at a normal interval which still would be every 5,000 miles. But if the oil is fairly clean looking when you drain it I'd go for an oil and filter change every 10,000 miles. It would be interesting (but probably not cost effective) to have the oil analyzed at the next change.

If it's burning oil I can't imagine the catalytic converter tolerating that for very long, so rebuild that engine. If it's smoking, do us all a favour and rebuild the engine.
Burning and leaking. No smoke, but oily residue on back bumper above exhaust. I have a replacement engine to rebuild to save downtime and it's complete with cat.
 
The engine sounds like it’s beyond the point of no return but just for an experiment you could try using Restore and Protect to see if it helps in any way
^^^
I'm no expert, but I would have thought that giving Valvoline Restore and Protect a shot here would be worth a try. That there would be more than the two suggestions for that line of action.
Wonder why there aren't more recommendations to try Valvoline Restore and Protect for 10k miles at least?
 
This is totally experimental but I’d move up to a thicker grade like 10w40 or 15w40 to see if it decreases consumption and maybe sub in 1/3 of your sump with restore and protect to potentially do some cleanup too. See where that takes you and if consumption decreases then it’d make sense to change the oil at regular OCIs
 
For the BITOG collective. What about doing a Berryman's Piston soak? You obviously have some history numbers of use.

Burning at that rate is not inexpensive to keep adding oil but I'd really like to results of a piston soak followed by Valvoline Restore and Protect.
 
At what rate of oil consumption does changing the oil become pointless? My daily driver is a 1997 Nissan Sentra with 425,000 miles. I’d like her to make a cool half-mil before rebuild or failure.
I would still change it, but maybe extend the intervals a bit. Otherwise you never have completely fresh oil to start with.
Castrol GTX 5W-30 and a Bosch 3400 or Wix equivalent.

There are not pointless oil changes, if you want to keep your engine in good health.

If your goal is to reach 1/2 mil. miles I wouldn't be cheap on the oil changes. As the person above said - you'll never have completely fresh oil. In general, conventional/mineral oil is no good for more than 3,000 miles. Even if you add 1 qt every 400-500 miles you are not changing the oil and old oil will accumulate on the bottom of the oil pan as you already noticed:
It reaches that midpoint. Clear on the stick, black in the drainpan.

If you live in Manning, SC and winter temp. doesn't drop below 32°F, I would go thicker on the grade let's say 10W-40 and also choose high mileage synthetic blend oil. It will be the same price like the conventional oil. If temp. drops below 32°F in the winter - drive with 10W-30 in the winter and 10W-40 in the summer.

In this case you can extend your OCI to 4,000 miles and also your oil consumption may go down too. Keep using the same filters and always change the filter with the oil. However, there is no big difference b/w conventional and synth. blend oils. So, change it every 4K miles on your own risk. 3K might be better, especially if you want to clean a bit your engine internals.

I would try these oils. I've been using Valvoline MaxLife 5W-30 and 10W-30 for about 10 years without increasing the oil consumption I already had. I was changing it every 3,500-4,000 back then.

Valvoline MaxLife 10W-40
https://www.valvolineglobal.com/en/high-mileage-max-life-motor-oil-sae-10w-40/

Castrol GTX High Mileage 10W-40
https://www.castrol.com/en_us/unite...astrol-gtx-oils/castrol-gtx-high-mileage.html
 
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More. It starts off slower, but toward the end, it's a quart per tank of gas.
I had exactly the same experience with my oil burner '65 Comet. It wouldn't burn much oil right after an oil change, then faster and faster. I chalked that up to the poor oils at the time (late '60s, early '70s).

It burned a lot of oil and I didn't have a lot of money, so the cheaper oils I was buying at that time probably didn't help. Probably not staying in grade.

That suggests a "thicker" oil might work well. It looks like you live in a pretty temperate area so a 10W-30 wouldn't be out of the question during the winter. And maybe a 10W-40 in the summer. What are you going to hurt?
 
There are not pointless oil changes, if you want to keep your engine in good health.

If your goal is to reach 1/2 mil. miles I wouldn't be cheap on the oil changes. As the person above said - you'll never have completely fresh oil. In general, conventional/mineral oil is no good for more than 3,000 miles. Even if you add 1 qt every 400-500 miles you are not changing the oil and old oil will accumulate on the bottom of the oil pan as you already noticed:


If you live in Manning, SC and winter temp. doesn't drop below 32°F, I would go thicker on the grade let's say 10W-40 and also choose high mileage synthetic blend oil. It will be the same price like the conventional oil. If temp. drops below 32°F in the winter - drive with 10W-30 in the winter and 10W-40 in the summer.

In this case you can extend your OCI to 4,000 miles and also your oil consumption may go down too. Keep using the same filters and always change the filter with the oil. However, there is no big difference b/w conventional and synth. blend oils. So, change it every 4K miles on your own risk. 3K might be better, especially if you want to clean a bit your engine internals.

I would try these oils. I've been using Valvoline MaxLife 5W-30 and 10W-30 for about 10 years without increasing the oil consumption I already had. I was changing it every 3,500-4,000 back then.

Valvoline MaxLife 10W-40
https://www.valvolineglobal.com/en/high-mileage-max-life-motor-oil-sae-10w-40/

Castrol GTX High Mileage 10W-40
https://www.castrol.com/en_us/unite...astrol-gtx-oils/castrol-gtx-high-mileage.html
Great points.

The higher winter grade can decrease the oil leak, and may or may not decrease the oil burn. In any case, using a thicker winter grade could be a good option if the weather permits.
Maxlife and Castrol GTX High Mileage are great suggestions. Mobil 1 High Mileage leaves a lot to be desired, i think it is the only Mobil 1 oil that really lags behind all the competitors
 
It reaches that midpoint. Clear on the stick, black in the drainpan.
This would indicate you're adding to oil that's contaminated, and it would need to be changed. But a longer interval would be fine.
The suggested attempts with Valvoline Restore and Protect and/or a piston soak, would be worth the investment if you plan to keep it.
 
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